. PART I.  
THE EFFECT OF HYDROGEN AND.
HEL-IUM ON PLAIN CARBON STEBL’_
' ' PART; 11 ‘

sous PHYSICAL PROPERTIES. or  
. "CARBURIZED - mans , .

Thai; for the Degree gf-M.‘ S.
MlCHIGAN STATE COLLEGE

Eldon H. Shotwell
- 179.41

V
V
.
n
.'
¢
1
5
|
a
‘ J

-.-‘-LA

 

PART I
THE EFFECT OF HYDROGEN

AND HELIUM ON PLAIN CARBON STEEL

PART II
S ME PHYSICAL PROPERTIES

OF CARBURIZED STEELS

By

ELDON HQ SHOTWELL

.- ' 1:: a! KYiflM“

A THESIS

Submitted to the Graduate School of Michigan
State College of Agriculture and Applied
Science in partial fulfillment of the
requirements for the degree of

MASTER OF SCIENCE

Department of Chemical Engineering

1941

q-

’\

up“ '5
'3 H

 

 

 

 

 

 

 

 

A C K N O W L.E D G M E N T S

The author wishes to express his gratitude for the

cooperation and guidance received from the late Professor

H. E. Publow.

He also wishes to express his thanks to Professor
R. L. Sweet under whose guidance the work was continued.
The assistance in X—Ray analysis, giVbn by Professor
J. C. Clark of the Physics Department, is greatly appre-

ciated.

5-32666

I.
II.
III.

IV.

I.
II.
III.

IV.

T A B L E O F C O N T E N T S

Part I

Introduction
Experimental Work and Results
Conclusions

Bibliography

Part II
Introduction
Experimental Work and Results
Conclusions

Bibliography

Page

22

25

Part I

The Effect of Hydrogen and Helium

on Plain Carbon Steel

-1-
INTRODUCTION

The primary purpose of this experiment was to design and construct
an electric furnace capable of heat-treating metals under controlled
conditions of atmosphere. Plain carbon steel was to be the subject of
study, using atmospheres of helium and hydrogen.

Particular attention was to be paid to the macroscopic appearance
of the surface scale and the microscopic appearance of the heat—treated
specimens. At the outset it was hOped that an atmOSphere could be ob-
tained which would be inert to the metallic surfaces. This, however,
proved to be an impossibility with the experimental methods used. Pos-
sible causes for this failure will be discussed later.

"Bright annealing" is a term used in industry for annealing in
relatively inert gases. However, it should be noted here that most of
the successful "bright annealing" is at present carried on with metals
or alloys whose recrystallization temperatures are in a relatively low
range. Metals and alloys, such as aluminum, copper, brass, etc., are
annealed at temperatures usually not exceeding llOOOF. and are fairly
aptable to a "bright annealing" treatment. Steel, however, recrystal—
lizes at temperatures ranging from 15400F. to 1650°F., thereby present-
ing a more difficult problem. ‘The only advantage seen in "bright an-
nealing" steel or ferrous alloys at the present time is to reduce the
scale formation to a minimum and thereby shorten the pickling, sanding,
or cleaning operation. It might also be pointed out at this time that
metals having heavy cross-sections would require prolonged time for an-
nealing, thus introducing a problem of greater scope in the so-called

"bright annealing" process. In this problem a time of five hours was

_ 2 -

selected and a temperature of l700°F., which is well above the recrys-
tallization range of all hypo-eutectoid steels. The samples were all
placed in the furnace before the temperature was raised, and were re-

moved from the furnace at room temperature.

EXPERIMENTAL WORK AND RESULTS

The first problem to be confronted was the construction of the
furnace. It was desired to have a furnace that would heat to a max-
imum temperature of lBOOOF. in one hour. Actual tests proved that
the furnace would heat to l700°F. in one hour.

It was decided to construct a simple electric resistance furnace
using Chromel "A” wire for the heating element. The wire was “close
wound" on to the center section of a silica furnace tube. The winding
was about 10 inches in overall length. Asbestos sheet was wrapped
around the tube between the winding and the furnace tube. Silica was
chosen for the furnace tube because of its high refractory properties
and its relative imperviousness to gases, as compared to other refrac-
tory materials. A round tube was chosen having an inside diameter of
1-7/8 inches, a length of 24 inches, and a wall thickness of 5/16 inch.
The tube was open at both ends for purposes of adapting fittings for
control purposes. The furnace tube and winding were supported between
two asbestos board supports. The furnace body or frame was a cylindri-
cal sheet steel cylinder 10 inches in diameter and 10 inches long. The
body, which was packed with asbestos and fire brick insulation material,
was supported between the two upright asbestos board ends. The des-
cription of the furnace may be clarified by observing its construction

in figure 1..

.wnfiammunm oponamospw cmaaonpaoo new con: mspwpmmm<

H oadmwm

 

 

 

 

 

 

 

 

 

 

- 4 _

As stated before, the ends of the furnace tube were both open. A
threaded steel tube with a cap to fit was designed to fit over each of
the ends. The caps were made removable to allow for the introduction
of the samples, thermocouple replacements, adjustments of various sorts,
and cleaning. Three holes were drilled in each cap, into which copper
tubes one inch in length and 1/4 inch in diameter were inserted and
soldered into position. The purpose of the tubes was to serve as an in-
let for the thermocouple wires and as an inlet and exhaust for the gases.
A manometer and a vacuum pump were connected to these tubes as well.
Figure 2 is a blueprint of the designed threaded tube and cap.

The means of fastening the steel tube onto the silica tube afforded
a serious problem. Furnace cement was first tried with little success.
It was found that the cement after being subjected to the heat conducted
down the silica tube soon lost its coherent properties and crumbled with
the slightest torque placed on the tube. This in turn broke the air-
tight seal of the furnace. A "steam fitters" cement was then tried.

The cement was composed of litharge (PbO) in a glycerine base. It is
essential that the PbO be in the yellow form. It was obtained in this
form by heating the red Pb304 to a temperature of lSSOoF. for 50 minutes.
Enough glycerine was added to the litharge to make a pasty mass. After
thorough mixing it was quickly applied to the tube joint and allowed to
"set.” This joint had excellent strength and did not crumble through-
out the entire eXperiment.

Hydrogen was used first as an atmosphere for the furnace. The gen-
erator first selected was a Hoffman electrolysis unit. Connected in

series with the generator in the order named were: (1) An ascarite

 

 

 

 

 

 

 

 

 

 

 

.572n51. 7zxsur
42 IWEGLD

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12 rub: PER m CAP CLEARANCE

 

 

S 7551. CAP
.z le£192>

 

 

 

\
l _.._.___._.—— “-1- i L.
TURNED DOWN FOR

 

 

/
fl—lu—45‘;g .
. “i!
.8
V.
N

 

 

_Jt_.

mum ED -—/

cassava: _ SEC TION A -4

 

 

 

\ V
L___

 

 

 

 

£7vz>FVWP7w~«sstzwe'cnannnauztez>
.477vszFvnsveE'lrzneww4<ns

MICHIGAN 5 TA TE COLL 5' GE

 

SCALE 05p}-

 

/“=/"
czdi‘é%;,.

ORA VN

 

nz/endi7 49715V¥Ld7

 

 

 

 

 

_ 6 -

tube; (2) an overflow bottle; (5) Sulfuric acid desiccator bottle; (4)
an overflow bottle; (5) the furnace; (6) an overflow bottle; (7) an ex-
haust regulator. Also connected to the furnace was a vacuum pump,
thermocouple leads, and a manometer. Reference to figure 1 may serve
to clarify this description. The purpose of the ascarite was to remove
any traces of 002. Sulfuric acid served as a desiccant to remove any
water vapor present. The exhaust regulator served as a pressure regu—
lator, keeping the gas pressure within the furnace at the desired con—
ditions. The thermocouple leads led, of course, to a potentiometer

which was of the portable Leeds and Northrup manually Operated type.

After several blank trials were made using the Hoffman generator,
it was found that that type of generator did not supply a large enough
capacity for successful operation of the furnace. It was consequently
discarded. Several leaks were also noticed in the apparatus.

The gaskets originally used in the furnace were asbestos. These
gaskets were placed between the end of the steel tube and the inside
head of the cap. It was believed that the gaskets were too porous in
nature and were a source of leaks. Lead gaskets were next tried, but
it was found that a snug fitting was impossible with such a gasket.
Hard.rubber gaskets were next used and were found to be quite success—
fula It was necessary, however, that a heavy coating of grease be ap-
plied on the threads of the cap.

With these final adjustments made, it was found that the furnace
*was capable of holding gage pressures of four to five inches of water.
Along with these improvements, it was also decided that a method must

twatievised to evacuate the air present in the furnace before admitting

_ 7 -

the gas. This was possible by use of the vacuum pump. Absolute pres-
sures in the neighborhood of one cm of mercury were obtained.

Instead of using the electrolysis apparatus as a generator, small
tanks of gas were used. This was done to avoid the method of infinite
dilution for filling the furnace. Small tanks of Hydrogen and Helium
were purchased from the Fisher Scientific Company. The analysis of the

gas was reported as follows:

Hydrogen
Hydrogen 99.8%
Moisture .2z
1 100.0%

Helium
Helium , 98.2%
Nitrogen and impurities 1.8%

100.0%

It was found that these cylinders of gas provided enough gas for
one or two experimental tests.

The general procedure of the test was to first evacuate the sys-
tem.to about 1 cm of Hg absolute pressure)then admit the gas into the
furnace to atmospheric pressure. The system was then evacuated again
and refilled to a gage pressure of 2 inches of water. Gas was then
admitted slowly to the system so that the exhaust regulator bubbled
about 4 bubbles per minute.

The polished steel samples were placed in the furnace in a nickel

boat resting on alundum sand, the sand preventing fusion between the

_ 3 -

nickel boat and the furnace tube. The samples, of course, were placed
in the furnace before it was evacuated.

All of the tests were made at l700°F. for a total time of 5 hours,
including one hour for the preheat of the furnace. The samples were
allowed to cool in the furnace. It was necessary to admit the gas at a
faster rate during the cooling period to allow for the contraction of
the cooled gases. The samples were removed at or near room temperature.

The samples used were obtained from S.A.E. 1010, 1020, and 1040
hot rolled rounds. Photomicrographs of these steels as received may be
seen in figures 5, 4 and 5. Figures 6, 7 and 8 are photomicrographs of
the same steels after a five hour anneal at l700°F. in an atmOSphere of
air. The grain size should be somewhat comparable to those samples
annealed in Helium and Hydrogen atmospheres for the same length of time.

The surfaces of the "air annealed" samples were noted to have a
heavy flaky oxide deposit. The oxide usually formed in air atmospheres
is magnetite (Fe504).

Figure 9 shows the condition of the 1010 steel in the "as received"
condition as 20001. Figure 10 shows the same steel after a 5 hour "air
anneal" at 1700°F. It may be stated here that the depth of decarburiza-
tion, although noticeable, did not occur to any great extent.

Figure 11 is a photomicrograph of the 1020 steel in the "as re-
ceived“ condition magnified at 2000K. Figure 12 shows the "air an-
nealed" condition of the S.A.E. 1020 steel at 2000X. Likewise with this
steed.the extent of decarburization was not appreciable.

Figure 15 is a continuous photomicrograph of S.A.E. 1040 steel an-

nealed for 5 hours at l700°F. in a hydrogen atmOSphere. The resulting

  
 
  
   
 
 
  
   
  

Figure 3
S.A.E. 1010 Steel

"As Received"

Mag. 200x

Figure 4
S.A.E. 1020 Steel
”As Received"

Mag. 200x

Figure 5
S.A.E. 1040 Steel
“As Received"

Mag. 200K

-10-

  
  
 
 
  
  

Figure 6
S.A.E. 1010 Steel
”Air.Annealed" 5 Hrs.
at 1700°F.
Mag. 2OOX

 
  
 
 
  
  

Figure 7
S.A.E. 1020 Steel
"Air Annealed" 5 Hrs.
at 1700°F.

Mag. ZOOX

S.A.E. 1040 Steel
“Air Annealed” 5 Hrs.
at 1700°F.

Mag . 200x

-11..

 

Figure 9
S.A.E. 1010 Steel

"As Received"
Mag. 2000X

Figure 10
S.A.E. 1010 Steel

"Air Annealed” 5 Hrs.
at 1700°F.
Mag. 2000x

_ 12 -

 

Figure 11
S.A.E. 1020 Steel
"As Received"
Mag. ZOOOX

Figure 12
S.A.E. 1020 Steel
"Air Annealed" 5 Hrs.
at 17oo°r.

Mag. 2000K

 

 

of
i1

\
J

1h

rw r? *Y‘(“ (-~ s u
(e)-C‘V.I._~(x_i "ILL/1 El

ntinuous Ph

Co

.7 a
/ ’.
161611.130

e1 Anr

J1
DE;

E.L. JUKU D

M
we

.1-
he

a7000‘

_~

I. .1.

III

1
I

.-

Deuth of Decer

1.5.

311‘

r
y.
L‘

shown .

0 £_
1 ._:

r.- i _»~'r
irom page

C: 1”.)

i

4~
U

 

HOOK

f\
/
I»

re

 

 

 

 

-14...

decarburization is appreciable as may be seen. The series of photo—
micrographs are taken at 200x. Decarburization depth on the prints is
16 inches which when converted to actual depth on the metal is equiva-
lent to .08 inches. Pits may also be seen in the series, which were
probably due to the decarburization reaction. They might also be due
to original inclusions in the metal which were "broken up" by the hy—
drogen gas at the elevated temperature. Figure 14 is a photomicro—
graph of the same steel at 2000K. Apparently only pure ferrite is
left. No impurities may be detected as being present in the grain
boundries.

It was noticed when hydrogen was used that the scale formed on
the surface of the metal was relatively thin and of an adherent nature,
as contrasted to the thick flaky scale formed in an atmosphere of air.

Figures 15, 16 and 17 show respectively the condition of the S.A.E.
1010, 1020 and 1040 steels after a 5 hour anneal at 1700°F. in a Helium
atmosphere. The micrographs are taken at 200x near the edges of the
samples. Figure 18 is a continuous series of photomicrOgraphs taken of
S.A.E. 1040 steel annealed in Helium, showing the depth of decarburiza-
tion. This depth may be contrasted to the depth in figure 15, incurred
:in a hydrogen atmOSphere. The depth in the Helium atmosphere measured
ondy'.02 inches, which was one-fourth of the decarburization occurring
in the Hydrogen atmOSphere.

Figures 19 and 20 are micrographs of S.A.E. 1020 and 1040 steel
respectively, annealed in a Helium atmosphere. The magnification is
2000X. Nothing is apparently revealed by their structures to indicate

any impurities or abnormalities.

   

Figure 15
S.A.E. 1010 Steel

Annealed in Helium
5 Hours at 1700°F.
Mag. 200K

Figure 16
S.A.E. 1020 Steel
Annealed in Helium
5 Hours at l700°F.

Mag. 200K

Figure 17
S .A.E. 1040 Steel
‘Annealed in Helium

5 Hours at 1700°F.
Mag. 2001

-15-

 

 

Figure 18
Continuous Photomicrograph of
S.A.E. 1020 Steel Annealed in
Helium for 5 Hours at 1700°F.
Shows Depth of Decarburization.
Mag. 2001

 

 

 

 

 

 

-17..

 

 

Figure 19
S.A.E. 1020 Steel
Annealed in Helium
Atmosphere 5 Hours

at 17000F.

Mag. 2000K

Figure 20
S.A.E. 1040 Steel
Annealed in Helium
Atmosphere 5 Hours

at 1700°F.

Hag. 2000K

_ 18 -

The outer surface conditions of the steels annealed in the Helium
atmospheres were of an interesting character. Macroscopic examination
revealed that it was crystalline in nature and extremely adherent to the
metal. A low magnification photo of this granular coating may be seen
in figure 21.

The nature of the scale was at first unknown. It was thought pos-
sible that it might be due to fusion with the alundum sand, or possibly
with the Nickel boat. To ascertain this a spectrographic powder analy-
sis was made on a sample of the scale. It was found, however, that
only the iron showed up in the analysis. The analysis was made by the
usual qualitative arc method, using a recessed carbon arc. No metallic
impurities of any sort were found to be present.

It was next thought that the scale could be identified by X—Ray
analysis. This was done through the assistance of Professor J. C. Clark
of the Physics Department.

A finely powdered sample was prepared and mounted on a cardboard
disc. The sample, which was about the size of a pinhead, was rotated
during the exposure to obtain random orientation of the crystals.

The X-Ray light source was capable of emitting wave lengths of
light equal to .712 Angstrom units. Exposures were made on Eastman Blue
Line strip film with a fluorescent screen backing. The current through
the X-Ray tube was kept at 22 milliamperes. Nineteen hours was required
for correct exposure.

A reproduction of the pattern obtained may be seen in figure 22.

From Bragg's Law, the compound could be identified by determining

dn° The statement of Bragg's Law is;

- 19 _

Figure 21
Photomicrograph of Scale
Formed on Steel Annealed

in Helium Atmosphere
Mag. 50X

 

 

x”’_“\
A Figure 22

Replica of X-Ray Pattern Obtained
from Scale Analysis of Samples
Annealed in Helium Atmospheres.

 

 

 

- 20 -

nh = 25d sinO

order of reflection

where: n
d = distance between two successive planes of atoms
A = wave length of light used
0 = angle of reflection from the atom planes

It can be shown that this relationship becomes

nh=2dsin 2

distance from center beam on the film to the pattern
lines

where: S
R = distance from the sample to the film

The resulting lines from the X-Ray pattern were measured accurately
on a comparator and the respective dn values for each was determined.

The resulting dn values obtained from the calculations were plotted
on a graph, as shown in figure 25, for comparison purposes. The dn
values for the oxides of iron FeO, Fe203 and Fe504 were plotted directly
opposite them. These values were obtained from tables published by the
Dow Chemical Company. The ordinate units plotted on the graph are in
terms of relative intensity which were also available in the tables.
Intensity values for the sample, however, were estimated.

It may be seen from these graphs that the scale formed is undoubt-
edly FeO. There are also indications of other impurities present.
These, however, cannot be determined. No reason for the formation of
the FeO can be given, except to say that the oxygen might have passed
by diffusion from the steel impurities. Possibly some of the impurities

in the gas might have been oxygen. Oxygen from leaks in the apparatus

r.I.2.r@.J&. .r

v.N

¢.N

mp3: aonpmwaq. no
O.N

Al. aIVQI

macaw: c.2368.

¢O

.H\H

  

- 22 _

is hardly feasible, due to the fact that the pressure in the furnace

was at all times greater than atmOSpheric pressure. Incomplete evacua-

tion could have been another source of the oxygen. In atmospheres of

excessive oxygen Fe504 is formed.

1.

2.

5.

CONCLUSIONS

Prolonged annealing at elevated temperatures (l700°F.)
in reducing and neutral atmospheres is practically im-

possible without some slight scale formation.

The nature and depth of the oxides formed in the non-
oxidizing atmospheres is different than those scales
formed in oxidizing atmospheres. Usually a thinner
and more crystalline scale is formed in the non—oxi-

dizing atmospheres.

Decarburization occurs to a much greater extent in a
reducing atmosphere than in either an oxidizing or
neutral atmosphere. The ratio being 4 to l in com-

paring reducing and neutral atmOSpheres.

2.

5.

re
(A
I

BIBLIOGRAPHY
Clark, G. L.: "Applied X—Rays"

McGrawéHill Book Co., New'York, 1940.

Davey, W. P.: "Study of Crystal Structure and
Its Applications,” First Edition, New York,

1940.

Danah, W. A-: "Annealing in Controlled Atmos-
pheres," Continental Industrial Eng., Inc.

Chicago, Ill.

"Metals Handbook”: American Society for Metals,

1939 Edition, Cleveland, Ohio.

Littleford, F.: ”Equilibrium of Carbon in
Steel in an Atmosphere of Hydrogen,”

Masters Thesis, M.S.C. 1939.

Part II

Some Physical Properties

of Carburized Steel

_ 24 _

INTRODUCTION

Case Carburizing is a process of introducing carbon into the sur-
face of steels to form a eutectoid or hypereutectoid surface. When
quenched from the austenitic range a hardened condition will result due
to the incomplete transformation incurred during the sudden temperature
change. Case carburizing is carried out only when it is desired to have
a hardened abrasive resistant surface, and yet retain a tough, shock re—
sistant core. Such is the case desired in many gears, bearings, etc.

This paper, however, will not deal with the hardened conditions de-
rived from quenching. It is merely desired here to determine the effects
of carburizing for varied lengths of time, using a constant carburizing
temperature and a furnace cool. Special emphasis will be paid toward
the depth of carburization and the effects of the case depth on the
transformations occurring as observed by the Chevenard Dilatometer.

For future reference it is desired to construct an iron-carbon
equilibrium diagram which is shown in figure 24. This diagram is re-

produced from the "Metals Handbook."

EXPERIMENTAL WORK AND RESULTS
The steel chosen for this experiment was an S.A.E. 1020 plain car-
bon steel. As stated before, the carburization was carried out at
l700°F. for times varying from one to eight hours. A pack carburizer

was used having the following composition.

B8005 10-12%
CaC05 2—-5%
11182005 2—“:570
Coxe 25-50%

Hardwood charcoal . Balance

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-25-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

     

 

 

 

 
 

 

 

   

 

 

 

 

‘ 1 4 J — 1 4 4 44 4 4 4 J-
H .. _ s . ... _ _ . ~ . 4.:: I. » 4:411 o.Y.om.’u¢.-.N .0“ 0.. M .
r, o.... . . . l. .. .. . . Iv. u vl+.7 to v #.94I6I¢.. v‘. .. .. .. .4 .M.
Q ... . . . . . _ . . .... h . . to o ‘71.» o 1.14 .pfltl‘. ....OL..... ...
..... g . o 7 ._ . .. i 491. . A. . I. ohfliH.Iflfi ‘9,70 ., .0 o...
y a. .Vth . .I I . 0V0 . . Iclonuqt no. I IATOOIOQ4I 0 T0... 0 It. ‘Ioll 1 J < ...!‘nITOII. TJ'O ‘. rt. {‘4 d 1 b 1 0 a 9.0
. . . .....v. .. .OtI. : .I .I . . _ . I . .H .
fl.... . . ... MHI.;J£|0+I .«IHO. wo4LIo . . o ‘4 ...i
.. . . . _ .. u . . .. .. ... ..< u . . .. . q... H. O‘J .« o A fitgto ... o. ...
_ i . . . . . . . .‘ ... . o. , q . . i . t: +.d<¢£ 0V ’ .w o lo .414. ...
H . . . . . . . . P. . . . H . «<1 I. n . . . o. l 31’ . o.$.o .. . . . tvto CHI.
< 4 t a 44 »
.. . . . w _ — .. . ... . . fl . n. o . . a . .. ot.. N01 LMWLY‘... A.
. . . . . . . . . . ., o . . . IN.” . o . . o . . o .. ouflnkooo-i.f ‘. +.MI .¢L
o. . o . r . . s . . .. .~. .. . . . 0 . ..Ab ore 7490 1.. . r-
. _ . . y o k . . .. . o . . . . . p . o o . o . . .kH . . inhot . .# ‘.¢I& . . 9 IA
finvlfiool o 7...: .. .... . ..AD 0; It, 01:11. Iv o.I.. I«.Io-o AT 'IIQ‘I I 1: o .u v»... V iaoIfOlI It a A00. 4 0 I‘lY-ll‘ovol 'I‘IltllOiT’IIOQIIOAOv A 1 44H 11 0 0‘
. . .. . . I . .... . . . ... v ...-..AI .. .?
. u . . B ....u; . . I .. . . . 2? :7 £3.51 In
. h . . Dr 9 .A. . o cyliArl.6lIA o. . . . Y»-o . ‘1}. o.IOI‘.fi9§oI%, uvIO . 3L
. . . o. . le » . .ir. ' . .o 3 ...¢.« 7.4%.. 0‘
1 1 4 4 4
, . c A; i _ .L 7.. .n.
. . ¢. . . o . . o .. .7; v. 1.. I1; r
vIAo u . . l . ... . . . . . .l. .t o ’ .106 I990 ..OA
- . H. . . . . . . ._. ... - a. .IIH 1.-. .1
v IuiTlo. .I c. c. . oil 0. A o I .. . - «v.5.AIO. .1 1T1. I .IOAIJTfioL tlnhvltl'vooltt 1". O I Infil‘laioo» <4 I ..-.-L]! _ i L 1:1
. lg . so 4 .. .... c . o. .9..A. . I . .s o... ‘olo. .9
. . .. . . . o. . I . . I. . t g . to.» ...t. v
o u b M . . . . .. I . u . .... .. . . .;V% .1‘. o b
. . , . ..A . cv.t .... .w.
0-0!.-lll0 IIIIIIQ‘J.I'III. II..." b l r 4 R 4 1
a . r ~ . H m.. I..._ . . «o .o.« a... Q. 4 04 .
. . . . .. . H . .. _. . L. a. . ... A .. .. a .
. GU . l . .. .I . . . . . .. ... n... . o ..
m u C i 4 _ s . .. . . . . I; A. ...r ....~.o. .. H
x. o-.I,— o I p o c. 0 0 u u . v a . . A. enour c I o . 1...- .. .5. viii“; .09»%csav 7115.1011. . «c I . 4 1?.‘091
o . c . . .> . t «.0! . v .A
. h . fl 4 m m . "l,"‘ ""l" '11'11'*'l ...t ..4 . .... .,.. »
. . 2 . . . . . a .. _ .. a... .... .. ..
. . hr, . . . l
11 1
. u A} I A.. . . . O. .Y. 4 . W
- _ . . . . ... . o . . ....IA . .
‘ l . . _ . . . . _ . oI. . .. a
. . . . . h . .
v. I.. o .4 ..I n. a t. I f .001 lvoolol .YlOIvJfiIoICOIQI.-A.o ,. o.-'I.A OO.A4I'II .I! 00+iooo an. 900. . 1000‘50 InnIonn. H a- 9-.. 4|1 O‘IOIOI a
. . O . . . . . , H . . . . . .04
. ..... fl . .. ..- . .
. . . b . i . _ u . A ..
. . . . . . n . o . a .
FII'III. I’lIrIO‘IQ‘I‘ofl ‘IJ.II.F‘n-lllo"llllrll‘-llllil.l 1 0 i 144
~ . o . . . ..H: ... . .. . .19
. . . o . . . .. .o x .. . o o . u .G I
.1- . 7 _ ; . . .. . . If
. — .t . . ...; l . c . o «v.
won. 0 0:00 :. . .. a.I . u u on I . ...or I. ..-. ......I «.oovIIIOIblIli‘¢.| ,5 . ...Itan. .I.JCOOI‘1LV‘OIuOo c.70.~.4.uotTIIOI-O‘IOVGivfitooIofll
r . . m V _ . ... . . # . o .06..
. . . . . ..... . u ‘ ...
. o » ... . . H..o. . * . OI
. . 4. ... . .. ... . a . c 7r
P i r . s L r
4 1 . i 1 <4] ‘4
o .. . _ _ o .0 0‘1.
. . . .. . . _ . _ . . M ..A......
. .. . . v . _. . 4 .o . .voo
. .. . o . . . . . o .i 1..
II ..1’! I... I A I I .0. to. o. I if. .Ifilv.I.vo I. 00.0.A*0tt.6‘rbn IA 10‘ on-.. A]: voiji‘lllblulv 01'.QIatL-OIQ.o olOIll' 1:
y . . o . . . . fl . # H ..
. w . , . u - ..—
. . . m . _ _ . _ . I ..
v . .
. [w L. . o
. . . ..H . 1 . . o . Ho. . . ...
. . .. .. . . . ... ..I v;
. . r . G. . . .r < l _ . . .rm. a. ..Iool.l
. . . . . . r . . .. . ... o
T grit. o . .u I It‘l .. o Ito- . OI‘lxlul .vl..¢0 --.-.v JllfiailvOtl-TVU‘OIA- c .0: ‘u n v 0.: O~.OOI ”
4 . . . 4 p.8 . . . ..l . . . .
l . ... . . . a .o . ... . ,4
» >1 b P
4 4 l J
. . . .... . i . . . . . .
. . — or . . . . . nu.
. . . . o . ... o . . . . o . o o.»
. . ‘ . . o ..
I cII I4. 0 90 u n . o . . I o n 0. atDOI A ...n1 1 .* ..v I '00-. O Jthth. 0 to: .AY.91.11O-01101‘IIOOIIIIOI II VI A 00|t-.Oo Yuio‘ll vi .0 OO'IIIIIAVIIOI'DQOII.
- o o o. . — _ . - . . s
. . i . . . _ . n A . .
. u m . L . x _ fl . . . . H . . . . .
. . . . ~ _ . . . . _ _
III... IIIIIOOLIIIII ..II I + i w o
. . o o . . . o. L .H . . . . . . . .
. . . . . . . o . . . . . . . .
. . . . ~ . A . . . . _ _ .
p . . . . H . . . . .
v o'o:.uubo v onl. . ~I .. .o .0! .0 o . n 0 ..II. ...vhlnv CIVIIOOQOA IIIO'OIIOTIIIn1UIOI. -aIv 1..-.‘AYI .009 4 OIAYIIOJJ ..-!4.,. v-ID?0‘ 1-00 9|»:ch 0000061. 4
. .r . . ..A At. . . . . . I . .
. . u . u .. M ‘ H! . i . a. . . — . . . 0.. |
I . e . o . . x . . . . . . . . K
. . fi . n . .. . . en“ .
> L 7 t > L7
. . . I a . . . . . O. . s .
. . . . . . o i . . . . .._ . . a
. o . T ~ . u o . . . . n . .. .
. . . . . . . . .
Tol-.I.o.v|Ilo..nv.oln ... I on ..-! al.-l.o . A. . ...- . .. slltolo' n2 0 «VI 1.--..VITIIOALII ...Ilulv o1..v. 4 Iltvit.--&..I ..I».t.0104v0..00ll00l£609045-{1+ p
. . . fi . . . . ”r . . . . ..... o . n . o .
. - . . u . . . . a . o . ‘ . n
. . — 1 .T . e o . . . H ..
. . . . . r . . . . . . . .
I o p 0 [ul
n o l . w . o c o
. a . . . . . . , . . o o . . o
o o o e a . b . . s a. o . m o i
. . E hf . h .. .. .. . . . . . . .
I 6.0.0:: IIlo.o.I. «I .co v ootoOI' Al'l-o. . q. o .4 u .50. lolcnlOOO..A UAI‘ o..A. Out I Iii..odo‘al to OIAIQIAVI:'l.00'olv4vc.I‘QYOAAT.OI."III|LIOI!IIOIIICIOIIL{IIIOI¢"I
. . g . o . L h . o .. . o . o c o
. . . .r . m . . » .. . . . . _. . .
. . . 1 V. .. . _ . a n I . s o o
. fl . . .Ivi ...I . . * . . . t1 a . H .
[ b V LI?
4 1 a 4 4 4 4 14 4 1 1T
. . . .. . . . L. . . . . . NUT: . _ 4
. . .. . . ~ . . v ...o. . . - . or *
. . . . _ . . e o . . . . * . . a .
. . i . _ . . w . . . .
To. I 9’15 tan'. I .. ... . I... n I. . I11 . o. v .‘qu IIOoo.o« -IAOIIlelI..I c.0v 0 4 «wul '0010 o .v. 0. ovAvIv'ua. t'vca...'tb‘ .IIlno
. _ . . . . . . . a. . A . . . .
o o n . l . _ . . o . o o o .. . .. . ¥
. . . o b o a . . r . s o . H o u . .
. , _ . . l . : L _
.l > {l4 , i 44 4 u .
. . . . . . k . . . . . . . m
. . . . . . . _ . . _.. . . . . p o ..
. . . . o . . . . . . . . . . o . . . . a
. . p . . - . n . .... o H .
. ottlnlvvbu .... .9 .. “IIY «no u . Ion-.. . . o .. . -. ... I. . . Io§oovottlr|$uqao Iéoovav.o.ntfi.40ullc.¢.. .‘OOITi‘ -Ii'.I¢I... .Ic. .oloolY.o'06
. . . . g . . . . o I . . . .o
. . . o . o . .. . . — . . H .. o
. . _ . . _ . _ . . . H .. . . . H
u . . . o
a L H r L. . . . L. pl

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

nCQMZM 0;.Nan 00 20 U¢m

- 26 _

The reactions generally assumed as occurring during a carburization
process are as follows:

2 co 002 + C

H 11

C + 5 Fe F950
2 CO + 5 Fe :1 Fesc + 002

It may be seen that the reactions are all reversible and therefore
require "energizers" to keep the equilibrium shifted toward the forma-
tion of the FesC. Common energizers used for this purpose are BaCOg and
NagCOs.

The samples which were cut to 55 millimeter lengths were then tested
on the dilatometer for thermal effects due to different depths of carbur-
ization. The dilatometer used for this eXperiment is shown in figure 25.

The first sample tested on the instrument was an S.A.E. 1020 steel
to find the normal thermal changes occurring when no carburization had
taken place. Results of this test may be seen in figure 26. It may be
noticed when comparing the critical temperatures obtained to the iron-
carbon equilibrium diagram in figure 24 that the steel reacts normally.

A general expansion is experienced from room temperature up to 730°C.,
which is the A01 point. At this temperature the pearlite transformed to
austenite and the ferrite gradually dissolved in this austenite until

the AC5 temperature was reached. In the case of the S.A.E. 1020 steel,
A05 point is 83000., which again checks with the equilibrium diagram very
Well. It may be noticed that a general contraction occurs through the

austenite-ferrite zone. Upon reaching AC5 an expansion again occurs.

When the alloy is cooled, the reverse effects are encountered. The upper

and lower criticals being termed Ars and Arl respectively. It may also

 

 

 

 

 

. Figure 25
Photograph of Chevenard Dilatometer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

-23..

    

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. . . . a . ~ . .. ..H . ... .. . ...: l . ... . N.. ...... ....
_ n c . o . . . o . . . H . . . . .. ..‘v enof . n .. .u.. 0..
. . . . . . - . o . v . ... .. A..~ .711 . M . I I. ‘ .. .. v. .... ..v...
. . . _ . . o. . . . _ . . . o. ~H.” .fi4 . a o .. .... ....
1".)+ldo¢l;0¢l04.nllouifiln.. o .OII I. -.l" I .v!-i1nola11vlfi0000011 D .IOIOOIovI'IvleOII.. bl'..I I. 11.09.... '0 r 4 -OI A O
. . . q . . .. . . . .. ...... . .. . H i. .....9...
. a . . . . . . . . * . ~ . . o . I o . I n . . . i . o o 19 71144 A. I
. . p . . . o . . . a. . 4 . M . . . o ._ . . < . . . . .H .Hu I»-1\9L.4t.. find
. . . . . . . . . . . . .... . . . .u . 4 I !
.V 4 Pl? L . a .o .— o c 4141.. O‘HIA 1 ,\r
q . 4 1 4 4 1. 1441
. v fl . . . . . . . . . . . 0 ....¢... A.- . >o4o .
. . .. . . . . . n .H . . .. _ .
4 . — . . . H . . - H . . n . . u o . . .... ...,4 a
. . . . .. .. _ . . u . ... .. ., .. .. u . _ o .. . .. .... .
. . . - . . g . _ . 4 .. . . ... «I ..fil . . . . h .. . . . ... .4
5.110 1lilnlt' . I...-.I .4) I.0.vc. fi-1‘14l1.I. Iootoiooa To...01!u 1.’4.o A-.- 1.1.131! p.110VIO1 .I. .Ho-..’ b .0 1QV'FIOdon4toi 11114}. t’LT‘vI‘l 109110.... 0
. .... . p . . . . . a . . . fi . ... . a. a . o .. a . .. 9410.
. .. . a . . ~ . . .. . . ... I. . . . . s _ . . . . . . i...
.... . . . .. . . . . q + . a ” - . fi. . .. . . _ . *. .+.~
~uo. . . _ o o . H ? > r * . . ~nu _ . . ...-
. 1 1 1 1.1 4 1 11 1 1 u 4 1 < < 4
. .... . . . . u . +I _ . . . .m . n. . ... ... .. no _ .4 u. . I0101+0.
~ . .. . “ . . . . . 4 . . .. . .. . . .... b. . ... . _ .. . .4. ..
~ . . . .. v . . . n . . _ .. . . . . v 5.0. q a I... .. . H . ... .o
. . . . _ . . o . . . . . . . .A...o .. ... . . . . .. I .. .. -.
IIIII.I'IO-.'I‘1.OI4- V..oxf a-.- 170.--.-. . .OIIOIOQIQ. . .9-.+I..1.1'-I6.9v.‘.. 'VIOoIII41Y.t"I'O I‘Ltfialv c‘tl1vItblCacl1T 100014Al-n‘tlnlb wolo1Y‘IIIIIYA‘IOl1lO b .1910. C-I+VII.|0II1
. ... . . .. . fi . c . . t .1. ... . . o . .
o . . . . . . . . . o . . n . .. q .. .. . ... o . . . .
. . . . . . . . . . . — m .o .. w . .. . —
. . o . . . _ .. a o. . o . . .
L . . H
1 1 1 4 1 4 1‘ A 41414
. . . . m . . . o. . . . . . . ... .. .
c . . . . . o o . o . a o .
. . . . . o . _ . . I~ ..1 u M _ .. o .
. . . . o . . . . . o _ o . . . . . ..
I ov»|OoIAvaI.O‘VOI .IA.0II ...olun' - IIQO w ...0. Ir 0.-.. no.1]... 1".V «I1. 7 udO.'ILI‘a.J§ 1.. 5 .IOTIIIILTQ1'I 1|I~wOO‘COII11 .OII lill‘4YO...tlvlvlv Y0! II'OI' Y‘Oj'iol
. . .. . . o . . . . u . . .. . . . h L . . o . . .
. . . . . o. . . _ 1 .. . o . o
I . * . _ . _ e # . I .. ..E. . o .. . .
. . . . I. . . . . . _ . .
p H
A 11 1
¢ o o o . A" . . . . .
o . . . o . . . . o . _ . . v
. _ . o _ o . . .4 . . . . n ..
_ . o . . . . . .
I ‘ ov IICDOII..OI.I . 0 .0|1 I1 . l v A 11» oIDloIIH .40 Cooli1 I b.li§||’. '5 0 .I001 009' 1‘. OO‘O:*OO‘OII.- ..I. [II1OLIOIO'O‘AIO‘11‘ .010 '1
. _ . . y . . .
. . . . . . . . a . r ..
. . . — . . f — . s .1. . . o . . ..Ito
. . . . . . .. . Q .
11" .Vl > L1 0 00 1 A
_ . . o . . . . . ” ¢....
. . . . . . . . . . . a. -. .
. . . * o _ . .. .q ..
. .. . . r . . A. . ‘.
coolOonoIAV I... -.x . .., . .Y c I. .VI ..---A- O T» 1.. -..IIO-II4.'.IA 11‘- I-III.,IIAO ...!!!nntll" .011 0.1. Dolllnil 0 >
r . o n . . . . a. .. Q... .
. . . . — . _ _ . . . .
. . . . . . _ . b c . a .. g
o o . . . .
.. B11 a - , a a
. 1H . . . fl 4 .
. _ ‘ . . . . .. o . g “ .. . a . .
_ . . . . . .. . . . . .
. _ D. . h . : . . . . ; .
«I 1.0! . m . a II. . q I . .ctll . 0 . .l 1 .0! 1A . III . 4 1|- . I . . TI! I '0 'I'ILTth I- kl. OQAT.‘ IOIII. r n o- I It|l1lt1tnbt|110 . c 0" >0 '1'] 0" Ii..lll'-l9l'-01u#10
. . . . . I. a . . c . ..
. _ . .. . W . . . . .
— — . . _ o . .1“ . o .. _ u
n . . . . ..... . . . . ..
1) h . p s . 1 1
. q _ . . . .. .. . * fl .
. . . . . . o . . _ o .
. . . — . . I _ . .. . . . . . .
. _ . . . . . H . a
- Q.I- .lbI . . i o . o . v .u I. A 4 n n I. .OI’ r. 1 I o a A Tlllvo YI'tI . . ‘0! 1:00 o . .0 er- 1‘ o o V9.0 VLYIOO9 1 f I .AYDI v I'll. o 1 . . a o IIIIL VII|II*I¢ '51; "vu1 ollInlAlntchAI 14.1
. u . . . . .. . . . . o . . . .‘ .
. . . . . o . o. o . . o ... . . .
. m . o . . . _ . . . ~ .“ .W
- - - o . 1 I. A
- l e . . .
4 1l1 1 < 4
. a . H . . L . .....l
. . . . . . . o I ... . . . ~ . p .... . .
. . . . . . .. . h . . . f . .
-I.I. IIIVQ - ~ . . ..IA . TIT- g II .1 . alto. In. vllo V ... I.IO.IY no'gTI-ll11010 IQIO14 10!. I. noIOIA.l.IOIIIIOIvOI10I 1.00F ‘111I0-1.1|I|. bII‘r 4
. . o n . .» w . .
. _ . . . ~ . . . .. . _ . u. . . . .
_ . a . o . . . . a o . . .. ..
. . g . . o . _ . > . i.
II > > 1 1 1 1 q
_ . . . l . . . q . . . .. . n . . l
. o . . _ . H . . . . H . .. . . o . .. o ..
9 Q . . o . o n . . .. i n . . .. . o o o -
fil - . a o g . . o .. . . o . . . o
I .l. I .c 06I13.1 ... .. oiwnlvlv. v1: . .1 . '0 I--tc-luool«lvlld.co.itlila 001111..!Olllel10.1. .IAIAO-v1'tivl..n..o..acl. 1.1,IIIIIA1..1I1OI'|VIJ .-IIO.91.... 0t’0--.thontltllo.v altuol ‘
o . . . . . o . . . ~ . . . . . o .
. . . n o . . . . . . w o . o
. . . . . m . o . .- . . .. v . . ._ . . I ‘ . m .
. o _ . A . . . . . . .
L. . _ r . H . _ D > H
1 11 4 1 < < q 1
o . . . . . w . .I ~ . . 0 . . . .H .
. . . . . . . . .. . _ . . . I. . . .
. . — . . .. ...... w . _ . H . 2. . . .. .
. H . . . , . ..... _ n . . u . .
I...|¢I: -1. I- on 1?. l ..vl .1I . 0..-- I.-|I .Il.-- o 0’01 I.- ocIIo... IoIY.||.TaIII9AI1|o1 luI-...Y.1T1Ioil1711.--f. A -.IHIIIOIOIO -.0 ol--.T.t¢oo-o.1|||llI99§onilAv¢ I t I;
. . . . . . . . . . . a , . o . i u .v. .
A <
. . . o - . . o . .. . . I n . . o . . . . a v
. . . . . . . . . . H.... , o . . . . . . . . . .
. . . . . . . . . _ . . .. a.
F >
I 4 4 a
s . o u . . . . . . o. . H . ... . .0. .
. . . . . . o . . . o . . _ u . o . .. #u. m
. . a . . . . . 4 u o . . . . . H
AIIOJIIIII. .I-..o..-»r I. o II. . tuvvut .0 .0. I. tall Q. .Illnl. at a I . 919.011.70.111. ..v‘r‘. LY--AQOII01 .-O."10|.?l-ooe.lqn YllutIOIIIIIIIIIi-b,0~|.v ..loIooeo 1 1 ILT <
. .. . . . ~ . o . .. . . o e . . ....A-Ol.vi ...- . .-
. . . .. . . . . . . . . . . . .. . .... -o ¢ v.lg . u..
. o . . . . . — . . .. . . . _ Q. n . .... .. ..I . _
_ I. L I — . .0 1 0'1 I. I I
. . . 4 o . . W F . o o‘ n o . k
1 . 1 41 4 < ‘1 1 4
. ... . . « o . m . . . . . o .9 .1 . o ...o .. ,.
. a . . . . A . . . . ... . I . v .9. .. to
. o . . . I . fi . ~ . + . . . .. . . . p .. . ..
s . . . . . . ~ . . «... . . .. ..H . . .. .. x“ A
.-- lo... I ‘.I..Y..v-ootl 11.. . s -. IOIOI I... .6 . I1.- 0. 1.. o.l.. -.o.-!-I- 100‘. .1I. . . O 4} ..v.‘ '10. 0" 0-. ....lo. .-. olT1o.v itvtuo 10111.1. Y-.|5.Lr.1l’.5il9li.l
. . . . n . . a . . _ . . . r . ..
p c ‘0‘ - u . . . . . . o o . * ... . ‘
. _ ~ . v a . o o .. a I . . ‘ . . .. h .
IL . . . . v . . . ..
H - 0 1 . m l
. _ . a . . . CH . o .. .. n . . .. . . N .. . u .
o . . . . . . . . .. . .
. . . 0 . . . . n'm . .. .. . ... .. . H. . . .....,..
. . . H . . . o . .. . . . fl .. .. . , h ole. . o
..000 OIDI It-...|1 Qt- ... o O DuaA 011.10- 1.10... .I .o. . o.» I. IOO‘IIII‘OAHOO $3.1.dnile¢1t‘.|fll§5n$.l¢.91fiw'0%llv‘.+TWI..J.'.!‘.9-.. .. o.
. . . . . h n . — m . . m.. . .. _. . o . . . ... o. . ....
u . . h . . .. . o. . . ... ... . ....A O. . ..
.- . m fi 0 h... .... ... . P.... ... ....L 67..- cool‘
. . L [>1 .— . V V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

.... Sc ... .. .> . Eamzm Emzomz no 20. vi

 

be noticed that the Arg point was depressed to 775°C. and the Arl point
to 700°C.

In figure 27 we may see the reactions occurring in a sample carbur—

ized for 1 hour. It may be seen that the shape of the normal dilation
curve has been altered extensively. The Arl point is found to be raised
slightly to 740°C. However, the austenite-ferrite transformation line
has changed its slope considerably. This is thought to be due to the
fact that the sample has undergone complete transformation according to
zones in the steel. That is, the case being of eutectoid composition
has undergone its complete transformation at one temperature, the Arl
point. Due to the fact that there is no excess ferrite or cementite to
be dissolved in this newly fonned austenite, the case again tends to
expand with an increase in temperature. The core, however, being of
hypoeutectoid composition has not undergone complete austenite-ferrite
transformation and will continue to contract through this zone. This
will set up an internal shear within the zones and the resulting expan-
sion or contraction will be a resultant of the forces set up within the
zones. Two zones were selected for descriptive purposes, but in reality
there would be many zones of decreasing carbon content extending from
the case to well within the core. The same is true for the hypereutec-
toid zones which extend in the other direction (toward the surface).
The A03 point, for the reason given above, is very difficult to define.
Apparently from the curve the A05 point is about 8100C., which is a de-
pression of some 20°C. when compared to the non-carburized sample. The
cooling criticals are apparently 805°C. and 660°C. for the Arg and Arl

respectively. The occurrence of the change at 805°C. is not obvious at

--4A. ..-.—

' V
I
Y
'

f
I
-..-Q.--“

-... -....- —.

cu.

h

r627

t Qn,of s.A.E 1020 s

0:01.1«0a..

v

...-p--..
-o—

ma

1

0

.
.
O
o
w
.
o
"

.oll“t|co

I
-- ; --..-a
t

.
. .
.
.

.

'I'O-OII

o

0
¢ vO'TQIIIJ

.
.

...-,.-..-
.---..-.-

O

I

. A
-.-.Jr-_.-
- ‘0

b

n--§v--..

 

. v~.9s~rru.$- 5d,

mcmmzm quNOmz no 20. U+M

- 31 -

present. It is apparently higher than the Arg point for the 1020 steel.
The Arl point was depressed to 665°C. and occurs in the same relative posi-
tion for all of the carburized samples. It is quite logical, however,

that the Arl point will vary that much over the range of compositions re-
sulting from carburization. The lepe of the austenite-ferrite transfor—
mation line may be seen to be quite different than in the non-carburized
sample. The same explanation may be given here that was given for the
transformation during heating.

Figures 28 to 34 inclusive are dilation curves derived from samples
carburized from 2 to 8 hours. The same general effects in the critical
zone may be noticed in all of these samples as was noticed in the sam-
ples carburized for 1 hour. The tendency is, however, for the case of
approximately eutectoid composition to become the predominating zone in
the transformations as shown by dilation. This is quite lOgical, however,
due to the increase in the depth of case with a longer carburizing time.
In the samples carburized five hours or more it will be noticed that the
apparent transformation zone is narrowed down to some 30°C. which is fur-
ther indication of the predominating character of the eutectoid or slight-
ly hypereutectoid case.

Continuous photomicrOgraphs were taken of each of the carburized sam-
ples. They may be seen in figures 35 to 42 inclusive. The increase in
carburization depth may be noticed with the increase in time. These re-
sults may be more plainly seen from the graph in figure 45. The depth
of the case in each photomicrograph was measured to the zone containing
about an S.A.E. 1040 composition. It may be seen that the carburization

rate decreases after about a 6 hour period. The cause for fluctuation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-52..

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. . . * .... ....
+ . . . . .»4 . u H.. .+ .. A..." ...M ...v a... 0.... o... o . .. M H ... .... ”Hm.
. . . . . . _ . .. ..-. . . .k... . ... .:.1 '9‘. .... ... . . o . . k
. . . . . M... . .W..¢4. . v...... _ .. .... .... ... H. . L n . _.‘ a“ W ..4
. o u. . I‘v? _ ‘ F 4 .O Ibsttvtli‘léliit‘ ovlo .‘LFI’QTiOI'o 4
-..]. “54:! n . o“.t .9" cl 9|" lv'o'i onclulbtan.Ajv “It‘ll. vOVWHDI .... Hi. 4 . H. . A Muvoo .0... Qt.'i . u * . t . l ..h .~ .... ”H“. Molofl“
. . o o . . ... . .5 ... 07097.?0 v0<<< ._ . . ... - ... p .
_ . .. _ .. H . W . “y ......w n x.” . . I“. _. . ; 7. :. .17.... 3:
.. o. . y o .10 .v . ..o4 . o.
. . .. . 4— ... a . .. .' . . o . .o ..o. .10. ¢o_. H .r .
. . b H L. . . - w ..n .. 2...“. H. . .. . . 1
4 . 4 . . . . . . .. . . l
— _ . . .. .. . . . . o. . . . . . A. . .... . .... .... a . . . . ..- . .. .. . .oo .. o m
. . . . _ .. ._ . . . . , _ .... . . . .. 1........ ... .. l .. .. . .. .. . ..
. . .. . . .. . . . . . . . .. . . . O kl Ir 4 O 0 49.611
. . . u . . ... .5 . it It). 0; ..Vll-vl? 0.0- OIVIIIOvnIO o.§10.lv 11..«'O-0f61§z+OLTI'OOIHII| 4v..4 . 4 . _~ ~ — o.—
Q 1LT ....vla. .ooobocabol. .|.HI'I||.T to 4. IOJI'ICIO Tll 19!; . Ln. ._. . o o . . . 0 o L o o o
' "lv . O..v .. . o . U A. I. O CQI 00' AA UT‘OO - 0- 9 II. o In!
. . o a . ~ . .H . . .a . . . ... w o . o.” . d c. v. . . . .At 0. ~ . ... 0‘
. . . . . _ .. . .. . . .. . ~ . .. . H. . . .. ... ... 0m .4 P 4 fi _. d
a . . ... . 4 - o v . . 1
n .. . — n .. ._ .. .. . .H . 4 f _y P ~ 4 4 .1 k
. L 4 4 4 4 4 . H .. t . .... . . . .— . .. . o . . . c.
. .. . . l . u. . .. 4. o. _ . . ._ .. . ... . ’ . a. .. O . . c.
.. a _ _ . ... .. . . .4. . . . . .. _ . . .. . . . . h . . . .
_ o . . p. _ 4 . . .9 o. . . ..¢ . . .. . . . . . ... .. .. . . n . ..A ~o ~ . . . a .
. . . _ ... . - . u . o . av. .. o . 4 u. .4 .IH P O. 119:1 I'll Illl“ OI . rtnllv
. . . . 4.. . .043 c Ill- T r 4 0|- 0i: 0 '0. I J ..l 4
v Y . '0'1014.c..g.l‘lll‘.lalu.oo.‘QIT'QAQITAv.v YI|.9.1 Alon-I$‘- IOOOHIIIIIV q t. . . fl . . 1.. .. .H.. . .. .o . — . . . . m .
--I‘II‘I b h 1. I . . IO. . O O
. . .. 4 . n .. ._ ... . .. S . 4 . .. . .... .. N N H u .
v V o p A ...‘u l 0 u 0 a
c I o a _ . V . by ‘ P
. _ . . . 4 a H 4
4 0 fl . .. . . . .o . .... ....
- . .. _ . _ q . .. .n “ “. ... .. . 1..
. . o . . . o. . . N . . . . . . . . . . A .o4.al
. . . . a '9 Oh T «10.0..--» t. c---o¢oo9llt...ma. v ..Olqvaw-uTa. w o-.- m
. . . . ..0.4. no]. .-|.¢I t .ll.0 ntnvo .. l a .c . . . . .. to?
4.... Q0.» . u -904! ._ . e A. . . ¢ . .. _ . . n .. . ....ols.‘
. . . n . .a . u 8 . . . .. . .... .. . ........
. . u o _ o — .. . . ... . . . ....W‘.q.
. a _ . . 2 o s . _ r . L
e O . . . P 4 .1 4 .
. H . 1 . q E T, . H . _ . . . : . .
. ~ . e — . . . . J . o . . . 8“ .. ...._ H . .
. . c . .
. . . . n . . A ~ 4 H . . f. . . . .. . . ..
. s . — - . lvfiltn 4|. OIIIOIOL OIQIQ 11. .> .041 of 'IO-Q
. . . . . — o v . v '11 - VI" u . 101"; A . -Qlo‘In tlvlll ..I- I I n . 1’.|| 0.10 I at A VIOIO'I Q Oll . *IO‘IO“ ' i9 .1 . do ILA
. 111-.-; 31..-. .........4 . . _ . . . .
{+914 0... . . .. .. . o .. .
.. . . . icy . . w o. .. . . o
. . . . . . . . i 4
. . . . fl . m a . . n i 2 _ . . .. . . . . .
Iv. _ . b _
. IL 4‘. n t 1 ..- ilFii . . 1 . .
I b ..4 . . v . H . . l .c . H n .
. . . . 9. . .... . . o y .. . . .r . 4 . ... .
. . . . . . . . . .. a . . . I
. . . . . . . t o .. II.|9. II |A.¢vvloll.dL, 0'19} 1.Iolso .0n'i?’!0|¢.1.|?*oi-OL
. A H l‘ .a . 'I60~II‘... tlIOxOII..-v . A infi.ti 01-6: 4 0 A r v . . 9 . o A 5 a. .
A .l.. .-. A. 'v.. +11 ¢.4.. - . . . . ... . .. a. .. 4 .. . .
o . . m . .. . ‘V n... . u . . ‘ q . .o _ o.
. . . u o .
. w . . . a . _ i H . . o L. b .
~ . . u 4 t, ['u M .1 44 414 ‘
. . . . . . ...
_ . . ..
.1 . l . . « . . a . n n .. . . 6hr. W . m . .
. . ~ . . . . « i a l u . . . . .u a . O
. o . n . . . o . .70 . n . oIO'OvOLIPC.o%.V-I. 0'4'IQOII r vlcloltn .JIIOI'IO.I|'.AY 4.00‘41000+‘l"'
. . I-.. I . . - 77'! a V... .n c Jm‘ . .. . .
‘4 t..'.. I at cl: .00. 0.0 4: I6 Ill u+ll ..I. .. .9 4 . . . la . I . .. N . . M
. . 4 b .
. . . _ . . n . . h . D C . a . . ..ua . .
a o . . o . . . . o R
c o . . . p
. . . . - h 4 . 17¢ 4
a 4 'l! h _ . .. . a . o . _ o A H ...
. . . . . . . . o . “p . ..V o4.<
. . l . . W . . . .. H. ._ . . . . . n . rm xxx:
. . . . _ . .. I. - it 1: 5+. .1. f ..
. n I" .. I4.‘ --- " -....ll ~|l‘.' ‘
u . . .0 I P .cv... O‘Oltlooll ‘ t|.a.w Oil... 1‘ 0 CIA - .o O o o . . . y fi“;
- v-‘tlvll n aolll A. c.VI‘. n I ala...‘ ia’--.o a . o o _ T . “coal
. . . . . o . l .«l. . .
o . u o .. o . . H . .... o .... . o.
. . . _ . H . . . . . H: . . . . .
t a D
. o . . a r 0 4 4‘ W L «4
4r 0 4 M. . o n . .... . w a... aoab
o . . . . H. . H . o . . o . .. ...». .nu—
. H . .. . . . . .... o . .. . ... . . a...
. . . . Ill .0 'Ilr oIVlv-t.O§..Il..o. IoiYTollolfiocVIOI-Iql$190.?uOIIIoLVII'fwlr 4 “I11
. u-- -.. .l o¢ulul col -.. 1 4. out A. ..rllt.-. <..n6t.TA . . . . . . o ..o.
.6:. . . yo ’1. . . . . . . . . .. . . . .
. u U . H H u .v . . o u ..c o . ++~#
. h . . . .- . . . . _ . . . . ..
. . . c . 4
b. . . L t L . . . . . . . .. w . . «..l
4 . o . fl : . a . n . . o — o ... . $o<4
. . . . .. . o . . . . .. . o . . . .. a ‘Ao;
. n H J . o . . c H M H . o . 4 . a o . ‘I.
. . . . . . . . II. -I. cit-0:61.4I ‘ . fol. . .II .0 ..o' Totoo'lu- 1'01; fultv¢l c » o
. III! <Y.l..vv.Oanlva ..lioilnlllivoinl'tlslot.vutl [9| .7. o 0 H .. .. . . < u w¢4.
o I‘lliu llclu A'. 0.1'IIA.II.J..A.|. I... v . o o o . . u . H ., . . .. . .t . ¢.*o
. . H . . . . . ‘ p _ . H _ o H . U . o c .. ok¢w
. H . m . . . . . H m o a . . . 0- .. . . .ALst
. . . . . . t m 4 b_ 4
4 . . . . . o
. v . a o n . a
u - . H . H . . . . . . . . . .2. . ... .
. . o . . . H . y . h H 4 . . .. . . . +. . . .
m . . . . . . . . . . . . k . . _ . . . . . -
o . . . . v o : . ...... I H.10lvllo Til I4“-l&o I. o 6".-. -‘lll'obit -Ilo.‘. QAI1|OOLTQ|I.vtl'l!-'nr-1l.+~|0ivn. 0 3L . H .v 6. 4
140:--. V. a'tl I‘lolvulItulloO'OO CO Only- ..5.0 I0 9 o o . o o o v a . .. ...”
. . . . . . . H . . . o a a . p .. .. o. b n . . . 96.
o o a o . o . n . .. . . . . . o . . on . w o H. a ....
.. . . . . . . . . . . . . . . r
. . . . I» 01 I? u
_ . u L - .- ... ... .... . .. .1... . . _. .
. . H. .. . .ll»,.. .v u. H o . » . .. ..o c . v'uoI; . .. .. o . . ... .
— . a 5...: a. on I O I v ‘ l - . 0 ~ 0
a. . . . o m . . r . notov. . . .. . . . H.d Q. ... .H o. . . .HAI... ‘ to?
. . M . . . . . ..u. ..... .. t .v ...... i . .. .. . .. P 4 4 I» > Ilolll
. in. f .0 -‘I 14. 1 l v I . 0" a I .
VIII..OIH6|61. econooltlt. ovOIQO- .A c‘.|lov.001 \I.ol v I ‘t M . .r . .....H..W. . .. . .. . .. .....4. ...H o . . 5... do . v
. . . . . . . .. . .... ... 9 .. .
— a . . . . . ... .. ev+iw.... . H . . n. OHQ. .. ...¢ . H. ...¢ . ...ch6. 14.. .. . . . . a
. .. r. . . 4 ... .... . . .. . . . .. ..w. o 4 . u. .o.. . . ..—.».v.. ... ... I- . O p
. , . .. . .VI .. . . o.... . . . . . t .
._ . a n .r- . p . 4% Into ., . . .. .
_ _ 4 1 . o I. . . . u no A . A .. v .o .
H . . U . .-. .. ...1 . U n . ... nv . m .- . H .. . .
o . . .. v .. o . . . 4. .. . . .. ~ o...
.. . _ . U AV...“ . vb . ..H .. . o u i m ...._ - ... .. . . . ..
. . . . . .u .u .. .4 . . o . D It'llfiu‘i ‘§I.'|O|1YIQIQLY|.II‘ 4
. L . o In . . 1 o . ul ‘ To 01L l a II! . I ii. a n 9.0 oLTll'o (.016 917». {Oil I.-- ¢ . I . o . o a l' H A . . . o p
| I .- noxfi'ot 0| O 04: 1.. o... it v .. a .c . .. a . o . .o . ..p
.....o r o... . a . 0-. N . . .. c. v _. ~ ~ * .... .. .” .4.... “ . . u H
. . c \. . . . . ... . . .. . . .. . . u a .-
. . a . . _ . . . .. L. H . H .HL . . . .. .... .. . .. ... . m . .o a a
. . . . .. . .. o .. y r 4
4 4 . a . . ._ . . . .... . c... owv
, . .1 . . ... l L _. . H H.. u.. "I.-. «.- .. ... .. ...L
H . . . . . . _ . H g “I . . . .. .. . . . a. . . .. . . . .
O r u u o D I 0” . I s a. O. '4 . I ... CAV. ... ~. . I. II n
u C .- I’.
. . . H « . . .. . ...1:31.::I§ :11... 1-1.2:.-- I41.i-1.1+:1.--1-..14:9 . .. .. .
H . u o u . . . A c o - Y. v 0 4 III '7 70'. IV. 0 v..- i n 0* a 0 14w n . . t H A '4 v w n o . H . . . g4 I. ..p .. . . . . H . . . o 9 t . . . . . o o o o . . v . . 4 o . o
ht] 0-4. a _ - v . .I n . 6- ll. . I II 0 . V. . .I ' 0V.
. .. .. _. . _ . * H . M .. . _. _ . ... ....M...uo L...m.o.u no.0 .v.. .... a. a
. . H .. . . . H . _ . — . ... . . . t r » Fry
“ . . . 4 . L

mCOmZm 9qusz no. 20. QQM
-. 7~r"-.9L $.Ip

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

         

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-33..

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I . 4 . ‘ ........ 4 l4 4 4 4
. . . . . _ m . . — .. . a” w o. .4. . a ll“. .. HIM. 4.00“ ....
. . . . v . . . o . . .I . . 4 Q... . . .. . . I“ 4 4... ....
.. . . . 4 H _ fi . ‘ v. . 4 . n . . . .. . h. . ...
_ _ . . . . o 4 . . . . _ . . . . ... .H. 4.4H
Yulollotlv- 1.--.9IIIJ ... wtlu. .Y..n¢'0ulc 00.0. '.l. 40.014 .00.]..1..IO .Icl- JII0IT0‘1 '4': 111.00.. cl'ljivc;v:0n I01 1 o... Ilobnvll‘vllvlu’n oo‘fuloloL 0.00-99‘1T‘ «4 4..— 4
. . . . a . . . . v . .. .4 ..q. . . . .F . .4. . .. . .. 0.0. c... .
. . . . . . .. . . . . .. . . . . . .... . r . .. . .H.. .v.. .... ..
. a . . . . . ._ . ~ .. . » I . . . . .... o . . < .. .... ..09 - .o 4
o . o . o . c c » ...: . * .4 Q .v.AII~ o<v. 4o<4 .
. . o - 4 4 4.
— . . . . M .. _ . . H . H o .. . .. v ...«m. o . a .- . . .H
s o . . . . . . . . — u . I... . . ...I II. p n0g . .0. u: g o.
* . . . . fl . . . . . . . .. . . . .... ...q .4.. ...L.A 0 . .. .. . J0
. . . . I u . . a . . ... . ...0 ..I» 0....0...4 . e. H « ...
I-‘04o..|x¢l'u II:...|1v.. I 0‘0 .1... ..v u.¢ II >09n‘u I‘ll «Iva ....Iaa'tl .I'OVIII'VOXO‘I.-. I.'..II‘ :IVI.IIWIOI'IIIO vIVIIOIth.'IL:IIIlI»IIIT.IIIA 4 4. .00. 4 b
. . . . . g . .. o 4 . ... o n o. . I ooc4 . a I .. 0 II x.
.. . . . .... . . . ‘. . .. .. u . . .. .. . . . .... ... . .. ..—.. . .. . ... H. .ler.
u . . y .. 4 . fl . . . .. . ._ . . . ... .... .~ A a. . ..4..
. . o . I . . ~. . . .. . v .
. > . 4 0 L p . * Ill
4 1 4 4
44. 4.4 . . . . u: _. . . . 4 M . o . o A
I020 . . . . ., . . — _ ... . . . c . .. . .M u
4'. . o o . o o . . .. o . «. .... .o . . 1. . . 0 u
.. . . o . — . _ o. .. o a . o“ . . .9. . u . — . a
1101.....- 11.1.: +4.-..oouabt0004.3.. 0001-..--- lvuvlu‘o. 7... 4 A5100..-IIO..$|.I'0IOL||05143016|4|9|‘|1 I uHIQoulwlotoalOla‘ln 4
. . _ . . . . . .. . . . . . . . .
. . — . n o . h . . fl . . ... 4 .o . o I . .
‘ . . a .. . . . . . I. u.... .n . . o
. . . H o . . . a .0 o . . .
. .l p i. . 4 1 4 4 4 w
. . _ . . . a . A . ... .
. . _ . . 4 u . _. . . .o . . o
. . . . . — . . .. . . . . ..”.a.. o.
u . .. . . . . . . ... ..
{1.00.5 '4!» - ct..lw ...I.: . . -I -. .- . .o ..u.... olv. .10.... «III-10-1.... ..lh30l'dirklIl4'vo Avoo'LcnoIAVvuL'tl ...0.o«?0.l v--. .Iu cidluA
. . . . . _ . o . . . . . . . . . ..v
. . _ _ . 0 . . .. . . w . u .
. . . . . n . — . o a 0 . ‘ o w my a
O c o - I“ u t I O a u o n —- o
_ I > h P y .
4 4 ‘ 4
. — _ 44. H .. . . 8 H .... . 4a .
. . _ _ .. . 4. . ... . .
. . o I. o. . _ a .
> . . u . , o a
II ...-..0o 4......04 . .v 4. Y».-. t“ 1.- .r. .o .0010}. 0.0-.-l‘1jnnfqt... .-tllolvontlTIIOI-qr‘-n‘1fivvuo.vlr
YO. . _ . . o . c . 4
VI.m4 . o . ~ . . I q . o
7194.. . . o . .. u . . . o 4
#4... . _ . . . . 4 . . M .4
0 . L4 4 c 14 1 4. . 14 4
. . . . A o . .. . . fl
_ . — . _ m . .. . . . .
. . . ... . . ..
T'OI '4 .1 It‘d. A v I. w u. » . Iv 0“. ..bvliltIl‘Vlv‘III 0.1-0.1.00l IOIIIQIII‘r1l10LO‘
. _ . .. . . . .k
0 . > w a . . a a .
. o . W . . . . . .- .. . ...~
. L H H . 3 _
4 4 W 1 4
m . . a M u . .. u
. . . n o — . . ‘ c.+ . o . . ~ .- u
. . . _ . p v... . c .. u. .
0 . . . . u ..d HI . u . a. . .
I-I OI . y yotlv. .v¢ a . cool I .I in. v .0. «0| * III». I* tb'jilr‘t .‘0ut 0!! OYOLV U I'.0I|AI'{I‘II-+IVAT00I.
o . H . . . .. . . .
o J o - o p . o I. .
. m _ m . _ . v . . . . . .
. O I u v o
[r b
4 4 4 1 I 4 4 4
.... . . . . . . . . . o . .
. ‘a . o . . s . 4 . .
B .. . 4 . _ . . .. . ..
u . . . . . .
«loll a. .I I 0 0.].-. - I00 I . nloV I Ila. O - .1. H-.. .v wO‘l'L'b40AvI‘IIIII! .017yv.lo.a‘ ...III. 04'Q4v1r‘ {
. y . u . . o .. . . . . .o c
. . n . . . n . ‘ . . 9.
fl . u w . . . . . ‘ . . w. ... 4 .
. . .. _ - ~ . L. . - L. H
. . _ _ . H _ . . M. . g u
. . . o. o .. . o . .
. . . . _ . . . H « . . . _
. o o _ o . L .. .
In. 1 It! I v I. - . ' O o I - v 0 «+04 A ... II 0 0.. .OAv'vlilll—Illl.avIILv VI. II‘I‘I.L+‘IIOOOIIICA {$.I‘AIYIIIOIIII‘ fi’I’IILiIiLfi
. . . ~ . . g . . . o .A
. . . ¢ .- u . . p . . .
4 m . . . — . .u . * . .H . m u . - o ..4
. . . I . _
III . H w . B .
. I .. . n u . q . o o o
. . . . . . . . v. H. .- n . .
. . . w . ~ . . . H . . . .. y . .« .
. . . . . _ ..c . . . « g
a I c 4 l I u a . I n I I ll u . Al" I O . .4. u I - 0‘1. 0 .7. I- 0 v Jv A 0 4 I 0 . II o I III I14 - 0.1:. I OI Iu.'l'u ’10:! 0 In I CIblIII Y1. . r 4 11‘ 0 0 9!: v4 IIJI'I 4 4T9“ . 0 9'. I > .—
. o . . o o o . .. an. , o u .
fl . . .. o . fl . o .. o. . . u —. H .
. . . . .. w ... . . . .
. _ 4. . . ... . .
. . L. . . p . D .. L F
4 4 J 4 4 . - 4
L . . . . . . . ... a- .
. . . . . o . . . 4 . n . . . v
‘1 . o u I o c . O o n O . o Q o O. H. 1.’
Illanlb OIAI . . 00 011...: .0..... A. Elva-.60 o...Il-900L|041. ... uool'lfi‘. IIIOOIIIIB 00-11.0IIIDLIO l .IIIAVIII 01¢-g0VQ'fkiLIO4III+OI0‘iTIIIII+0I.¢4'l-.|0l IOATO .II 4 440
. . . . _ . .. . ... . . .. ... .
. ”A . u . . ~. ¢ . . .. . .. o n . . . .o . n. o . .
I . I o . h . . . . . . . I . . .
Y .. . _ . u . . . 4 H. W. . . . . o . . - ~
I... .r - - . - .
. . o . . . . o o . . . aI ....
I . . I M . . . . H o .. . . . . ..44 .
. o _ . . . . . . . . e o. . :r. . ...... .
. _ . . . .. . r . .. . 07-4}... ..4. ‘
T'Ofilvolalwvll0vylcv:c on . . ‘ ..-..L "tch 0.10: 0 III. In :9. .- $1.01 .1--I|L...Il'¢wluatwll‘u¢llollt+v|0t V lv-.!1.0tyvl0.| «I4
I . o o . . .. .. ..40....¢ .L-o.‘ .4. ..
o . . c H . . . . . .1410. . |.¢ .44 ..
o o . . . . . 4 u A u 4. .I0AY>.. .. .0 I... ...
. u . . 4 .. u I! . ...
H . L » Ll r p . . . D I. .
. 4 4 ... H . w .4 . . 4
c . . . u H ~ . . ~ o m . ” .44 u . . ....
.. . . . v . . . . I . .. . . .
H . o . . u . . 3;. . . o . i . . .0 o . . o. . ... .
I . . _ . . . . . - c . . ... y .. . u .. .. . H
I." III... ..:0. AIV100-00-0 Ir;- .10oIA I 000-411... c.11rIIY1OIOI0. T..I- .OIIIOIII'JTct1.4I0'Avbll0lrvOnofi ['A+400'LII'vIvvtfllI-O.II¢II‘II1Y1I009|1|IIA1IIIIOIIOIIIAIv
4 . . . K o . - . . a o . I
. . . . . OH . m . 4 o .. 4 .v H o .
v . I . . .. . g ..
I . . . n' . . . H . . . . H w c . . . .
fl}. . 0 4r . . fl
9 .I . . u u . o . . . c. . a . .— v I .. I
o o . s . .. n o . . . o . . . v ~ a . . .
. . o 4 . .o o . — o 0 . . w . o - o q
I . . . o . a c .. . < . o .. .~ . A .
.IOIIIIIIIIIO OA'I0A.I . 0: Ion. .. .I oooto '0 0|..0. . .o . ...]..vlvl l.-IIIIOJII00I‘0..I.LIIOAIiT*ll|10xn YIJDIII"I+|40OI[IOI
. . . . . . . . . . o ..~ . o . . . o . . o . .u .. . .
. .. _ . 4 . I. . . . .... . .. . .. ....
I . . . ~ . 4
. . . . . . o . I . ~ - . o I I . o . . a I .
. . n Lg . o a H L“ * — 4 .. m bl: . ... qu.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

.... vtarc n..nu-nr

mCszn Enahmmz 00 20. U...“

 

 

 

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1‘- 1* 4
. . 41
.- _ M 1— 4. J 4
. 1. M. . . M. . _. M . M M M M
9 ¢ u. A . H m .
M . M 1 .. ...... A M 1M M M .
. . . M . 151 H.1-111IM -. M. s¢ . - A. 101 - . .
M . . M . M M11- -- .-:----M1 -. 11113:-
1 M a 1 - 111-1111 11 1M 11-1 l1.M-1 11.1111 1 1.. , M M . M _ . -_ M 11.1-1,
. M M . --.1 :- -11-1l1 1-11111- ---11--.M . .1 .o , _ M . .M
. M M M M M M .6 M - 1M 1.
..M u . M . _ 1M _ M . eM M M. H H .
. M . M. . ; ...—1b. w. ..... -M ......... M - H
m m _ M M. . .. S . _ M M 1. 1 1 .......... M 1 0| 1 A 1 . 11.111-
1. fl -- - 1- . . . M 7 M M M
.. M - M D 1 M . .. M M _
M M M M M «01 , M . M 0 M .
-1 . 1 v . . t — . M
. M M M - - .u .; l a . M M . 0
f M . .M M . . . . o . 11 1 1 . . a 1 w .1 .11 111-11 1
11.1. r .- 111 .9- ..1.1! .u m ..I.. ll4..fi-. . a . . .- s ..1 v.11 . -. .uI1-I.. 1 . 1111.4. 1 .1111 M- 1..lu|1 .. ... #11 . . . .M .W M M 11 o. I I
. . M . M . e o. .. M 1--. M 11.1- 1 inf-1-11 M
. M M _ - r A MO . .M M M M
. n - - _ u . ..MH .. - M. . __ _ M
M M . . 88—. W .......... ¢ 1 _. I 11 t.
11:11.11- 1 1» M _ .1 74. M M .. - .
. M . Til 4 1M . . M .
. M 11-M1mw d _ M . - O M M
. _ . 1 r ..
M M _. e _ . u _ M
_ -. M M . n z M M 8 . M M .M
.- M M . O i . .M. 1 1 . ..1 11 ..... M 1 .- -1 1 .
- 1 M1 ..... - . . - I... -- - M .1 r M a M ..M-
M M . , 11.1.1- “1 111nm WI!!!- »11 . M . M
_ M _ . a _. M1131 . . . L
0 c M 1 r . .
M M M . . .1 a . C M
M . D C . ..... . ..... Min-y: M
vlllIIIu-lilkll.0l1l.|ltll . ..ll I 1II-- '11-1.tlo 1.? M M M . ..1 . . 1M 1 u w1 l
.. 1M . . M M. M n . M
M M . k D 1.1 .M .
.M . M . .. M M ”NW N 1 .1
M M. . M . .- ; -- . - . - u _ M
- 1 -. ...... 1 1 M M . . - 11.31 -. 1. :M
M . .- -- M. 1 1 1 -1.; _ M a M M
M M M ----.1111-- - 2-1-1.-- r . M
M M M M . 11 1.11161 11-M- -.1
u M M p . .
M . - _ 1. M .
- . M M . a 1m.-;- . - 1h .
. . 13.- .1- . M T M .
M . M _ -. O M -M .
. _ . H 1
. . . M. _ M 1.
M M u M I .|.- 1 _ M
M M . - . M . - . - .- ----- .M .
.. M M . , 11.11.1111-- -.M:-111.1-1|1-.11111-1-1111-1.11;.11 1-11.1171 _ M
M M _. ., M U _ M 1 -
o a . . - .
M M M 1 w ‘ .l * u . .
M . M u H 1 v ...... ..I o s . .
. M M . M M M 11 -- --
. . Ill-1| . . - M M M M U .
H M M .. M . 1M . 0“ M
M 1 M - . . h .M M M Ml-
M . . M 1 1|. . 1 1 1 . . . M.
M a 9 .1w .1. o * I'll M
71-111.111.111}-1.-1. fl . M M _ 1 . 1 - I- .---.M
. -.--1111.1711- -1--11-..-11 11 .11111'1111- 1.11 1-11. 11 1 111-1111 . M M . M .
M . Ilf 11- 111.. IL]|T1111~ 1' 11‘1111 1 11 . _ -
M . ._ 1.1 A 1.
... M M. u M. M . _ M - ._ .
M . . . , . . _ _. . .. . . . .
M M M M M V M, r .1 .f M1111M.1:;11-. .. M .
1. _ . . . . M .. . . - --.-1111.7111- --1
_ M M . 1 M M . M . M M g . M M . M M
. M A: M H _ 1 Mr . M M M . H
M M . . M nv M M M M p 1 ’ L. ..
_ . - M M . . c P
- M . 1 M .-__-11n_-.-M . M M . M :3 M M G M M .. . .1.
. _ .. M ”'3 M .11 . - .. ...... . . -. 1 -M..
Y1! I 0 0.1.1111 111111-I .IIIAIIniII11III11 < J A M u M M M M MYIIO t . ITW‘ M1 H.
. M11131f1111-1 M _ . . M . . Mk;-
. . . M . M -- -.Mr. .- .-.-11111111111111; M M U
. _ . . M M _ M M .- -_
. . _ .. . . M M . . M M M H . . U M M _ _ M M
M M M .M: . I M M M g M :M g M - M
M . M . . . . . - I I 1 I u . o . . 1 . L1II'.‘ OIMTQ‘1l-1 o - A. 4|. .111. 1 4 u
M . .. .MM ., MM
, F . M .. M i H .. M ... M U ..M
1 1 pf fl. M. R

 

 

 

 

 

 

 

 

 

 

 

 

:33: :MCNM-MM-z no 20 wbm

a
.

191+
.
4
¢

.
»
a
VO.I‘II.'I
.
.

.

.---.a -.
l

qu—fgcco

 

2121...... .2 C ..> MCGMZM DadNQmZ 8 20. WA.“

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 <1 I4 4 4 4 < 4.41 I . 4 4
4 I. w A 4% . H A .3. 1 . .. .fi H A 4 ... . 1......TV-H 4H1 47?. ..
L.H . . a . fl . + .. II . .. «... o . . o IITWI 4.y.0.¥1§«. +30% . v
.w . . .. . . H . ...-o L . . . kWK—fi..1A. » m U “ 3IATHI- . U6. “‘14“ o <4 .
. . . . . . 0.39.9 . II. .. II I o .v o.
. . . . . . . _ InI.llI r vHIHIIv IoII .LTOIIIocI-I . I4 .ovOI-c-IOII .ovIIIolk IIIL It. A IIIOIIIILIIIIOIIIIQIJ'QIIII43.»
III. III. I 33..IVII4-I.. VIII III O-II. ..103I I 301110 'OIwnoIrvA...II — H HH+ ... o o .3 ... - .. p _ « u-IOII3 off-fin HVI3.3¢o-_. ...
I. h .. . . . m . . - 1o. . . . . .v... . . ¥ . III ...-..- o-t 1?“.
1. . . . . . . . .. o . . . . 3 ‘1.“..n. » ~ . . .. . .r‘v. ..-I.O I... Mir-H9<k. -
. . . . . o 3 . . a .. . I .III. IovaA I. .6
W3... . . h . . H . . .. w .m . 3 . . a 3
. . . 3 J a a . H . .1311: ... . ... H .. “In.“ .H H?
. . . . ¢ ‘ . 4.4. ¢.|. .. I . _ . n
w . . H M — .. . . . u o < HQ... c.03. I‘M. . . . o m . H - . 3. '.I
. a . .. . ~ . . . ... . 0.. .... ...._ .. . . .. ...
. . .III . II33..III III-OI . I. IlinluIiI-I v .33
. . . . a . . — . . n I ..3- . . _ . . n c. . I..
. . . . . _ . . h . . y . . ....
. . _ u . . . . ‘3 — M “NH” r H ..NH N v .u . u... A . “Q
. — . . b- . H 4 .. b w u I“! .
I . 4 u I o . . - . . o.
u .. -. _ . ~ . ~ ~ . . 5...; _ . . . . u . _ .._ -. . M ...
. . u .o 3 . ... . . . . ..¢
- . . H s . . . . w .3.» . v - . .a. . w w “ .A H a 3.3
. .c . . . .. - u .. ..
III .33}- 0.3... .3 .0 . H IIH.- .AVII .u-n .HII o . . ii]. .3 3- ...-I3I . III v 33 I . IIIYII'II” I. ful.IW.IIIo-¢III¢IW .-.Lf-IOIIMIII11HIIII17II.‘ N1 . J. HI.
- h u - 3 . ~ . .. 0 U ‘ o o .0. t V O V
— h w a . _ . k. n
-. . H . M . . a . . . h . . H . .. . . U .. m .
.. u . . . _ 3. 3 I, .LV 4 4 d 4
TIIOIIIIIOIIIIIIII [.1IIIII .5 I N M I. . d ”1!. ¢ . . .. . .
_ . . . . . 1 a . . . . . .
. _ . _ . n . fl . _ . . . . . . ... . .
. . .. a . . . . . .3; 331.3--- . 333-1-3L33p-r.-. ”LL. L333- 1133-3-13: .
q . .u .4 I. ... «inc. ...II< too . uclvt .33.. I+.un..-vvlv&IIoIt 3 -IOII III. i . - 1 o .. _. .
YII4I... udIIv-II ca. . . v 4 _ . . - . o n . . 3 _ a
. . . . . . . . _ . E u . . 4 . . . ... . . .
u . . _ , . . o u . . .... . . . . ..
. o . . . . — .
. — q _ . L . .. . 1m . > .
4 3 0 . .. - H 1. 0 .3 ..3 m . - a H H -.
. . . . .. p . p . OH . . . .8. a . ..
. . . . _ . . . .. . . . .. ..
H m _ * . n . m u - a” . H . .- M h . . * H .
. I II III: I ..l 00 IQIIUIO VIOI.OY-Io YvIIIIIIIIIIAIIIIQ It 9.0II4
33.. III-II.-. I .l. 00" I» IIchv<I o 3..I.. I . :30 .II 36] I'vovollIIl .0 1 FA “I o . . . . n 0 IA
1'. O ‘ — . v u 4 .
. u . H — .. . _ . . . I to . . fl -“3 a. ._ . . .
. . . . . . . . . . 3. .
. . . . c . u . . — .3 » I .
. 3. . / 3L w - 1 3 . 3
II A . . . . 33 .
n — . Q — — I p Q . n MB . n I < O I . I‘ C
'- - . 9 - o o . c o I .
v. . .
l O n
. . i. .333 III: II: 10.13...- -IL -333»!
T.“ u I O a . l 3“ I I u . I .. II. n 4 H . . 9 III a . c I o In“ . n I I1 i . 9 o I. I 3H3 13a u 3 3 V. II. I III 4vI IIILTI 3 3” I. O ‘ 4 H vi . . . . 4 - I
. . . . . . . t. _ . . . - ” . x” H
u . . _ H . . . h a . H . . - o .m .. .H .
. . . » 3..» RP . D o 4
. o . 1 I 1‘ 4 q I.‘ .1 . . . - .
3 4 . . . . .. . m . _ 64 .
H . _ . — * . o ... . . . . . a n o I
. . . . . . . c H . ? . I.
. . . o . . . .. h u . . . L . . a o
I O c 4 0'! ‘1‘. . 0 -II IIIA- - ‘ILI‘
I . II n. I A H ... 3. . .~ .00 .3. oil. to: 3. . I .. w oI .01 XI v 3IIIInIL3 c.3«IIILIOIIIIVI.AI AIIJIYI.OYII.....IIIII¢ .IIW . IL. 1 . YJ‘IIIOI I.
. . . . . . . H . .. . H . . 4
. . . . a . . . . . . . . .
I—3 It. I L. I . r y no 4 fl
l ‘I .1 .l 5 Q n.
- 1.. _ _ . . fl 4 . . .; .
. . . . . m . . . ...H . . . . H. ..
. . . - . .... 3 .o
. . _ . . 1.3.. .-- : 3I.L--3-3-.:. IILEFV
l.|-..I.I 3. .3. l . . I“ cho 3. .1:. .0: -uvnuto- .Ip... -L* .I. 9.: - 331voII3- I . . ... . — .. .
. _ . . . . . . . .H ... ..
. _ ~ ‘ . a _ . a. H . .m A .
n v M . N _ - <
J“ . . h _ o. . .-. . _ . H 3. .«_. . ..o 3
_ . . _ . . . . _ . u. . . ._ . . . . . 3
. . . . VI.YIIILYI|OIII. YIIIIIIIIII .II 01le YQIIIIQIIII YIIIIIIfIIIIOIAT. 3
.. poo . 3. . I c c o . 3 * -.. a... .I 3 «...: . 3I34I.0 VII III - - . .. ¢ .m..|.. 3.3
. . . ~. . v u .- -. I.
. u . . — I 4 _ . H * . M . .. -. .. 3. ..
o . _ . . o . H o I.
_ . .. . . I 3
4. . o . . . . . . 3
3 a g . m M n. . . . . M . .
u . I t I W n I
o o u h 3. 3” u . .H H H ¥ H. s“
o . . . . I. II YIIIaoII VII-II. W-IIIIIII YIII‘IIIIL1.IIII III3 TI 0.. 4
-1 ..I .3.- ...... 33 .3 1.-.-3;-.-31311----33,1.-.33 31... J1. . . . . 1 L . ..
. . . . . o . . . . . . .. . ...v
. — . .. . . .¢ . . . - . - . . F a... . ..4
. . . _ .. ..- .H . . . . - . .. . ... .
. . . ~ . .. . L 3 N 3 «F .rI
. . - M H . . . . . . 1.. . H. . _ . .
.H o . . . M 0+ . o . . ... u . «.. . 3 . v ..3
o . o . . . .. . . . .. . . a. n
o . o . . . n a . . . H. . 1 0 I33
. _ . . . . .. . . IlvuIInuv III: III I53 I III II! IIIICIIIIILIII I»
II III I I I3I I A I I 3o I 3IIvII 0 I u c I IIOIAVII t n I n IFI I¢3. . I II I I 9 u I I I III I 0 LI III‘ . I 1V0..- I. . 93} I I! H p .3IIIAV. I I a II ”I Aj N . .71. H: N . 3 M n H .
fi ‘ u o .“ D o I O . u - 0 c . IOADO
. v o H o. . . . . . . g H . r . .m .u... .
. . .. . . . . y . . ‘ . . . . . . .. .. .. _ .-
. . .... . . . . . .k r 3 L L I 3 . »
I I > I III 4 . .0 u c .o. . u . c 3., o. I .. u.
3. .- . . . . . . . . . . . .. - . . - .. . .. ..
0‘ h. 0'. s . c Q _ u 3 C Q d .v I I. l H I O.
....t vIII. . . .o m . . . . ‘ . . .. u . . .. . * u . o .
2.3le . . . _ . H h .1- h 4.11.34.13.11-- 3. - 313.11.:-
1 > a 3 . I.. 33'». ..--3.3.30... 0...... oil. .... ...II 3.. '3..3-tcivoI.o .33. oIoI -01 III. 3.3.. .3 . . 3 . .. .3 1 . .. . .- .
.4 3 ..I u . . . d . V o I . ”.3 u . 3 .. v . o." .. 3. n. o . .. .
Y A43 N .330 . . . . . . . . .33. _ . 3... . a . .. .. . o . .-
I...glc y. . — . o o . . — 3 _ . I... . ..u . .- .. M
...‘t < I N . - . . . . 3 . . o _ L F
.+I.. I. . -.. r 3 > 3 - L. 4 3.
T p 4 4 _ ......u .H.« . 3 . . - . c H . 4‘ H. v » .3 .~ I. a
. . . . . . . .. . i . . v. . -. . .
. . . _ .3 . . . .. .
. . . . . . “v.3. . .293...“ _ -. . .. _ A u .3 n .
_ .. . . a -. . . . - . . p
. H o n “o . co IxIlIIIIIIIIO OI 1113.0IOIAVIIIII.013II III). .-I tho¢.I IIIO<IIAfiIIOIAIIITIIIII
.. I... . I. 9.Iclg II ... 3 III a... - OIIIA Icon. _ K 3 .9 .. . J. _ . H « u. u
. . . . . .. . .
. . . IO." . .N . w _ . . . . . - .
. . '7 .0..6 3.. . o o o . _ . . A
n . . . . or . .. s o. . .> .3. o H . H w
. > I 4 I
« h . H . . . . .. . . .. . . . . . 3 . H3. r
. _ — o . . I .. o 3 . . . . . .. .I . . . v H - ~ 3
. . _ . . . _ - . .. I M . . H . .. . 3 . .. . .m . ..
o . . . . . o H .. . HI . . ‘.. . . .I . ...3. I v .1
. . . . # VIII. .ofiIIo IIVYIAIIOI.-3l..¢IIIIb.IIf slot-Io: I974 41 .Il.. III. .
I. ...I.. . . .. . I .I. III. IIIIII fin IIII. - 39.... 9| 00"; H . ... o 1. . . . . . 1 fi.. . o c . s I o
. “ . . . 3 .o . ¢p . . 3~ . u .. ... .3.. no ... .... o- .
. . « H . u . . g — . . . 1..“ . H M. . ...” .th .... ... .... ...3 .70‘ .... . . a
_ . . _ . . o o ‘ . r». » 4 . r b . Dr?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. ......«o C .7. ...r’

mcmmzm gmdfimmz no. 20 wA-M

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

-37-

 

 

      

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AI 1 I4 I i 4 I u I d I 4 4 4
I . . .I I I _ _ . I p
_ I I _ . . . . .
. — . I I . _ I I I . .
. . _ . I I .
. _
II I I I 4 I u o ‘ l I I II b D I r l I Q I I I IL ,,,,,, I I I I g I I} Q 0 6 II I I II I O D O I I I l. I II I
. — I a . . I . . . I r I.. . vII . I If . J
n . A _ ¢ _ _ _ . . .
i — . v . . ‘ a . I W
. I I . I I . . . . . .
III: III-.. --. Ii- II- -1 - - . II?! . 25+-.- 1.13-1 ..... I. - . :I: I . I b I I I I I
I I I _ I II . _ . . _ I I . I . _
. u m _ . _ _ W . I. I I . . . ¥ .
. . _ I . I I . . o .
...T n... I. . w I I - H . . I. III. --- .I I . . I
I . 4 I . . . u . o b I A IIIAI ..III I. ‘‘‘‘‘‘‘‘ I . . . . I . J. I I . . I I I .II I I I I . . .rIII IlIleIIII.IL.|I I I.IT I I I I I I I oIIIIIII
I I. . _ I m _I I .. . . . . . I. I
. . _ m I I . . I I I . I . . v
I . _ q I . . I I _ . . I ‘
I n W F < v . . o . < 0
III-Iii '«I 4 a I I I 1‘ h I
. _ I . I . n . J_ lm . .
. I I + I e I I I .
~ u . . .. . _ ‘ . . I
I . . ~ . . e I f .
. . . I I I . I I I I . I I III III III. . . I I I I I I. IIIIIIII .II II .I . I I II I I .III . . I I ,, IIIII I .III
_ I II . . . t? .IIIII. . . I
_ I . S _ .
. . _ h .
.. . . , I . I
I I I .I I I II. I I I. I I II I I I I I. I I I I I III. I t I I III . I .I.I I I IIII. I. .. I . I. I I . II II I I I I I . I II V I I I II I I .I .I .Io III I 4 II I I I v IIIIIIIII QII .I 15 .IIIIIII ’III I.II.I III II. Io,l. II IIIIII II II ..III F
If I I 4 4
. . I _ m . I . _ I I
_ J . I _ I I . u . . I .
_ . I 0 t I I I I
I o w I . . ..... ilII I II I . 1 ...... Iv I o I I I II I .L.. II III II
I I m I l .Ia u . I I I .
I ‘ .I . . . . Ev I. - I I _ I
. I. _ . . II I .
H _ . I A . 8 N v n I
I II III A. o v I, ID! _. I [I I
m .. u I u . I—I . 4 I
_ I I I I... ...u I _ I I . I .
. . I I . I . . . _ .
I I . Io . I _ I I I
u . I u o I 761. II.IIHIIIJ. . .I . II III. III {I c I ¢ I III I I 4 II I II
. . . _ y I _ .
A I . S . I I I _ I n .
d I _ n I I. I I _ I . .
. —. . I 7 . . . . .
IIII‘III'II“ ‘ICIII’IIO I I I Q I! I III I [J . II ID I I .- ..- [I I I I.- Q 1.. -.IMII’D 'III III OIIAV [\CIII‘II III-.IIIII.IIIJ'-I' IIL.III ’I } I{
I I I _ _ _ a I . .m, I . _
. . _ u . I - — .
I I . O .6 . II I , I I . I
. _ . . _ H I y _ I
I a . . ~ . I I II.-. I I I I I II I .. I. I IL I I III I
I I . n ,3 I 14, I ..
I I I A v 1 . I I .
w . . I . I
I I 1 L I . Ie . .
I III I I IV I If? I
.I I I I I
I . . .
I .I a .D , I I I . I“ I
. I . h I I .
I . l .r I I It .
II p . I I ...... . . I I II I II IIII . .II II II I I II III II
I I . .1 .QII I I. I .I I I .
I I D c I . I I
< .- I ‘ r I .
. _ I _ .e _
I I IIIII II I I I I I Q I I I . II I I I I I . ..I. II.II|+...|I IIIIIIIIIIIIIYIJ...IIIIIIlb. I.III I III I III- II I I II IIIIII ' 4
. _ . V I .. _
g _ n - § u _ v
I . H . . _ .m . .
.- . . I . I _ . .
I . . I I I II I IJT w I I 4 A I I r I I I II I, I I I
. . . .
.I I I I. .
. I I I . . _ .
. . I I .
IIIIIIIIII I I r I I w I
I. J I I I . I
_ _ .. . I I I _ . I
o v . fl _ a I. . . V . . .
. _ . n . . . _ . M I I II
I I . _ . I .
I o . I I , M . I m . I I . I I . I III II . III III I III , r I lo I I I I oII II r1 III I
I . I . _ . I I . .
I . _ I . _ I
. . .. I I I .
. _ I . . . .
I I I 14, I I III I . II I I I I I I 4. I I II I. I III I IIoII I. . .0 II. .III I III III (I... III :I IIIIIII IIILVIIIIIII IIIIIII IIIYI I
. I ~ . . o .. . I I
u I _ r I . . I m _ . .
. I H . . . .
. . I _ . I _ . I
. . h . I . I I I II It. I I I ..... I I I.... .. . r .IIIIII III I I I II. I I
. _ _ . _ . _ A I . _ . .
I .. I . I _ _ .
_ I _ I . . I . I . I I _ I
I I I . . ~ . . 0 . . .
p I II I I I I
I a I I 4 q 4 4
I I I . . I I w . I . I
.. _ I . q . I A II .
. . . I I I. . . . .
. . . I I, . I I . .
. II III . I fl I I II I . o I- II.« I I I I I II o I . .IIQI.. IIvIII IIIIO III II III II
. a . _ . .
. . H v _ I
. I I . w _ .
w i I _ > ‘
II.II|I I. IIIIIIIIOII III .IIIIIII II.* I IIII III I I .III I I1. IIIII. I I IILI.IIIIII ILT II IIIIIII I I 0.III I IIII IIIYI III.I IIIIIIO III I 9 I
. I _ . . _ I . .....
_ . I . I I . _ . P
,. . . . I h . . _ H p M
4 . .. . . _ . . I I . . . . . .
I o . I I I . I e I . I . I o . I c I v I I . 4 ...... I IIIII I I 9 I I I I II I I I o I I I I I If? I IIIII I IIIII III II. I.IIII ATIIII I|¢IIOIIIII ATIII,I.II¢IOII,IIA
_ . . + I . . . I . . . . . . I
. I i . . . . . I . . . . — o
_ _ a . _ I . I I . I . . v +
* . . . . I I II . I .
.r I m r . Ir F
I _ I I I J I ¢ .
. . . _ . . I I I . I . . I w
I _ I . . _ I . . . . .
I I . _. I .9 . I I‘fifi I ...I .. e _ . . I.
. . . . . . . . . . I .
I I . I. . I . o . I _ . . I o W FIIIIH‘II I 4 I I I {III ILTIIIIIIIII A n I I IIIII T III.I I III ......... #YI I o I I I AYIIIII I I I
_ .
I ‘ I _ RI a pa I: II. . I . . .
. . . . _ . I _ I . . . I . I .
. . _ fi‘ _ . I . . I. . h . . . . . . . .
. w a . _ . I . ~ I _ . . . I .
I . IIIII OIIIII IIII IIITIII I I I III; .. III. IIIIIIIIIIII 4 O I II.».III I I I 4 |r I II + I III II I 4%
u _ I I o . _ . . I .
_ _ . . . . a _ . . . . . . . I . . . . ... . . I .
I . _ I . w H I . I I . I . I I I I . . I .I . . . . .
. . . . . . _ . . . I . . I I . . . I I
.I I I . .. .o I I III. . ..I. ... . I I.III.. .IIIY. . I. ...Iw... I I . vIIIIII..., wI. . .I. II. ..IIIIII .III IIIIII ..IIIIY. III. IIIIIIIIIIJIIIIIIIIIIIv.IIo III+IIIIII
. . I _ . I I .. . . . . I . . I
_ . . ‘I' _ h _ I I I . I I . _ fl . . , . I . . . . . I I II .
I a I _ . . . . . a I I I . . . . . . . . . . . I . I w . I . I .
I I F p I _ . I w I . . . . . . . . * . . I . .r . . bI I . . . I. . . a .
I y I > I
. . I . I

:ILMZm UIwINSwZ OO 28 u.».@

_
4
H

...-7‘ . .

‘I'qu11‘ o“ini1.I’Lc-il -

"—9 .... - 4.

.-. _ 4..

. ....
-:l+tl“.0.vl- ifloi
_ . _

... .

 

 

-~—-‘_4l_-._.

.........

..........

‘1
a
u
I
A

 

 

 

 

 

 

 

. ...- .-.—4

.. ..---. .... . .

 

 

. .0 Yuri-Al!- v.11

. .
4 . _ 4
D 4 4
M _
4 4
, .. . .
4. _
Titllxflurolvl.vy.w DA ‘.
n .
.

T231: - 24.41.133.19.)

 

".....-“ ...-... .—.-.

 

 

 

 

 

.--_—- bo— -.{ I . .

 

 

  

\- .-‘._...-._‘._.—- . -...-- _.._? .-_.._..

 

 

 

 

4
_
_
4
. .
4
1I1+ w. . -4
_
. 4
.. . m
In _
4 ._
‘ _ .
u p .
ITid-XL -.
_ _
.e. _ .
4 - -
.m.
E. 4
4¢4- LI-..;w.«‘ .
4 4

 

wipe

07.
,3.

 

. ..T._- 4 -. --- _.
--“__....- *-.4r_ .... - ----,. - .-.-.. --..-.» H-
- I

._._._

-1>-———--o——4

 

 

_-‘-. .

 

4 .
4 H
4 * ‘
. . .
m
.1 - ..- .. -- .-
. H .
..
II -Illlllllbllly .‘
4
_
If. . .
.

 

_-__,’., -

 

r
--‘7L..V.

,__.___.&.- _- -.4 . .._._.._.__.._- - 4 —. .
.

 

 

,_- -4 - . -4

 

_-........._

 

 

 

 

4
4 . _.
-ixérva. ,-.1...-ii-i?-4I-u--+l- 4..
4 ,
fl
_
a
H 4
* .
‘ w
m .
u _
n .
_.
4
_
m
.- -
c Q
_ -
.
t .lh‘lo‘xlvlrtv' ’3 I1 \
_
.
.
m _
W .
—
.
. 4.
4
. 4
..... . u
4 4
4
L45
_ .
_
4 _
. - _ ..
u
- . + . . .
_ _
4 __
1 4 4 4
.. 4 ‘ ., ., dew -.
M . ' _
4 4
I I Inf- I '14.1 «II If: ~11: . ... it. laii-l Al
. _
4 _ 4
_ _
- _
4 q H
. h
4 4
4 ,.

.-.“...

 

 

-. - ...—n

 

 

 

 

 

l
——.+ y-—- ....-—-

4- . .A-‘ ..

....

4 .yl. W 1..

4

4w 4

_ .

_ ...
w. .4

.- 4, ..

u 4 4

. 4:

m .

4g

4 .4: .4

 

 

 

":4:-2m ...:Zma2 00. 2.0-.

-————L - _-._._+ -—--——

. , .
Fv—4..¢7- .

 

 

 

 

 

 

. K" c '1.“ ' ';.“|~‘r‘ k“ '* ': " ‘ i '
‘K‘K .~ K \" wit -'K‘-K‘~§\=»‘v 's': trt‘mflmw'fi‘ 135’ “K "’5’?“-
D ‘ - . '. " -'|-. .'. ' | ' " ‘ a ‘ ""‘I'l ' ‘S
- - 4‘s”? 'd“1.“.’”-.if-"<3 m1 ~ WYA'fhxhK i 3,13 $16K") 4"“-
m-JK... K. . :5"? K
., ' ' a I. ‘ ‘ \' L‘ J‘ . ‘ ' ' '.- "Ff! ' s c
" . “d“; r" 5’- 5?» .‘K‘?! .13.: ‘ "' ‘1: ‘ L '-“$r ya”: ". “,.Y:,"\‘:0
K ; -.\'.‘~‘K~K.- ‘x ‘K‘f— KK w- 8 .15 N.- ..z-Iz- ’3“- .' ..K.’}.‘-.-- - '
D ‘_ .' ' ' J ' ' ‘ ’ ' v. “a“ i ‘ ‘ 3’7}... . ' ‘. l
t _ ‘ ‘ . . ..:.‘”%'J_-}:£;I“x’3lv ‘7"? A: ,II
- 2‘ vi! ,'\ ‘) " ‘

-f' ‘
. . .
(r .lil, -

.. ‘-V '3. I

fill} ;‘.:;hI 1
WVFK’X (3'1“!
"H‘N-r 2-"?
..' _ .

. . K. \v
'Pr . \.
M1”: l.’
._ Jr.“ 3
. - I

- ..'.i - “
g l ~5 38
‘ -\

.
L!
-
. .
\ . .
. .
. a
. . .
3 ‘ K_' ..
.
.~ 1- “
. v .‘ ‘ -\
. "
-.'.d- \ __
‘ ‘.‘ - ‘ \
-
' I
o " . *1
n ’ .

 

 

 

 

 

 

‘5

Figure 35 '
S.A.E. 1020 Steel

Carburized 1 Hour at 17oo°1r.
Mag. 1sz

from Edge of Sample.

 

 

 

 

 

 

....
o
a)
K063
8)
0
ON
HO
Sir-c
no
«4 0
rum
0
<3:
0
U)

Carburized 2 Hours at 170003.

Continuous Photomicrograph
from Edge of Sample.
Meg. 1601

-41...

N03 .3:

638% no mwcm Eon.“
Amwhwonoaoponm 96:34:80
..moooS 95 990m m 33.39.30
floopm Omoa #4546
en oaswam

 

 

 

 

, ... ......
fifif? ORJ. -

. r

0.. O
I n
t n‘. .
. . .0. .
...t.& .
F n . I
... I
»
. I ;
.‘l l A O \\
.-
O

 

 

 

 

 

 

 

 

 

- 42 -

 

. I .... ' I ..
L‘a ITEN {be 1'
r 54-14%"

‘. p_ . I" .. '4.

-- ......»
Q #1451 N‘ 6‘
.. ~ 43.:-

 

 

_, "o
' .

‘Qtf"m

 

.\ ,Y_
.N' - - .' .' p- "
c fl.‘ ’ ‘ ,-
”‘4‘;

I ::
~53,
'¥.V.,f’

)'?-

 

 

Figure 38

S.A.E. 1020 Steel
Carburized 4 Hours at 1700°F.

Mag. 1601:

Continuous Photomicrograph
from Edge of Sample.

-43-

Noma .wwz
.oamewm uo mmwm Eomm
nmemOHOHEoponm wdoddwpcoo
.moooua pm mhdom m comfihdnpwo
Hoopm omoa .w.¢.m
mm oksmfih

. n... 5.‘
. . / “‘43 n+3

 

 

{Haj ....... .. 4 .. . .l » Mgdfi<tfl S M.“ ... "(:‘W
.4... 4. _ , _ .F . 4. K. ..

..7: . .. ..o.’ ‘u . . ~.K . 4...
.RU . n.l~ 43%. .. x... s.
. $4.3... ._ Mvpu.4w~.w.v 4.7 -...
. . .. 4.4-? . . us. ma“ .31.. v... ; -.f.D.~ ..
.. .---.....va wk. .

 

\.

t . ’I l

 

 

 

“mood . mm?

.oamfimw mo mmmm Gong
nmmnmonowsopozm mdoznflpuoo
.bOOObH pw mpsom m cmwfihdppmo
Hempm omoa .m.<.m
o¢ mhsmfim

 

 

~... ..- _\.i . n.4u .f
- ... . :1.” . .. . ..rAjlvux.s.I.-
. . ‘ p .I u .- .k... a v ...
_ 4 . . .. ...! . . A.
. . ... . J .. -

A :. . \Q .1 <\.% (I ‘ . 4.. ~

. , 4 ,. A .. I : : .., .47 .a¢..

... . K»... I .4: w 04“.. My «.vuflrulh. .. .n
4.... . .. . . .. , . . a \c.
r. .

..c

\

.. ...4 H. . ., .-. . A. .. . .. ‘1.
- . .K .4...
.. av: . . pgrnntq
4.4... . i- ..
..d n . . .

b

... W1
1 . ..o
T ...

KmKK
3.4.".

 

 

 

 

-45-

 

. ‘ ‘ . :' 6 ".£;\' 0'}; d ‘.
. ~' .....-;.£’.‘K$rv','}:1¢$¢r\.

 

0‘ f)";-

V

' TV:'\ A ’-

4 .3.

- .“C' ‘V““ .. .-.‘-.l}
" " «4:330

. ’ “ fi.' - '

M' )3"; 32‘.-

5 "Ir‘: '. ‘
-$

 

K .-‘ .
' «‘1’?-
i‘r':'
I“

 

 

1020 Steel

ure 41
Carburized 7 Hours at IVOOOF.

of?
1L)

F
s...‘\oEo

Continuous Photomicrograph

“

ige of Sample.

*(

J

prom

J.

Mag. 160X

_ 45 -

wowa .mmx
.mHmE:m mo owwm 909%
zmwpmonoHEOponm mso
.hOOOmH pm annom m we

<1

.qucoo

mayonnuo

Hmmpm ouoa .m.¢.m
we onsmfi@

 

 

.1 . .I . . . ... 5. o. cl‘ ..4
.. ..lfifl....§ ‘5’ .. ~.\-\ ..‘v.3o..{ .5 . w -.
.. .. ...T .... J .t \~. ~ 05’. 5% (I ..... V.vv. .
. 7% I .I _ .JNM. k. .I. ’L‘uifl H... n c .n‘.):
. «r... .
Ilor. .

 

 

 

 

 

 

I‘ufitf’ F

IL!" '. o‘.‘l ‘IIIIIJI."\

l“

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-47..

 

 

 

 

 

 

 

 

     

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4 4 < 1 1 4 IIAJI 4‘ 114
4 J < . JI . a . . H .. .. ....¢ 4&6IA..o¢7 '74- . II... II-
. o . . . . . . . . . YI v . .II ‘_«.> .on‘v...s+ I H ‘H-«LIoo
. .H . . 4 ... . .. . I . 0?..Io». .. . :oo.4~fi[. .I ..m ..
. . . u .4 . H . II . _ .. .I . . .L. .0. n . . I.‘LI.AI+o 4IH“ 49,671 A..I‘ ... .
o . . IDIOIII 1.1- III A... IIIIII OIIIII Ill. OIIIOIOIIIII‘IIIOI 0110 rat 1 I I 4
‘lol:.‘9': III: OII.IIIAIIIIIIIIII ..IIOI«'9IIIv4 «.17 IIII|4vIIlo-QII IIIII Ii 4 44 ¢ 1 O 4 Jo. . . o I I. 4 o . ....fi oII“ Hfio4I¢IUI >
. . o . ~ . . . . . . ..I . H. '- ... . II I¢a.. «III I? Oulc - .
I v 0 O 4 .
m _ _ . . . o . .H M u . . H . .. .. . .*. .*.. .4..VI.«H4I¢II. I
a... _ .. H _ « . . .. w. . H. H- .. .... I..o.4I9.L. f... .
.r . .
.. u I I 4 I I I
. - T 4 . H u . _ u. . - -. : . . . . .... . .4 ...I. --.-.271...
. . . n . u I . o . . n . .. I «vvo. A . . .. . . I. I“. - 4&4. «o. 50 o ..I: IOI<I+
. u . H H . . w . . — . . .. .. o .. . v v I... H. . 1.. * Q-II .I. ..IO ‘00 o.
. I H . . . . . .o .. H. < ...-H. . .I. . .uveoTI ... I «I0.
. . o I [710 III .4 .Vl14IIIJ¢ Io IIIIIII .IIOI 7|.I601T I «ICIQIA’ wIlIl'. 9.: I|04701 III"; 4 4 00 H Inolto I 11 I|4
VIVOlII.I I: IOI -I IIIOIIIIIII OI”.III H o . u I _ H c _ . . IIo: I . . .» o ... . _4 I . I“ .HI.
. k . . o o I .. _ .44. .. — gov. I: . .. 4 . o. a
o . .4 . . 4 .. I. . ... .V e . v .. . o. ... . . ..
. . I . . . . H 4 H I. H .o I... I . . I . H I In . . . a 4 . I
. _ . .0. . . I p r p .
I I I 1 4 q
. . _ I . I. H H ...; H . . .H. . ; . . . .
. . . . . ... I - n o .I u ... a” 4 . o .u . .. .4. .
. 4 - . u I . . ... . . . o o . 9 Q. . _ o . I. .wo . .. ....
- H . — . filo . . . H H. u . o . . . . . .. . . ~ I I aLoout .IAI .I. YI74-L
. . . . . I II III. :17 I.. III III I II III I [III .{I+¢..IIIL11I.>IIIII:I _
VIII. 0 I... VII.I0’I¢|.I¢III'VIIIII v QIIOI III IIOIIO..I. A oIO-ullI..*IIl . III dlw. + '1le ”IIIOIH v .. . o . . . 1 n ... 4 I I I A.o I
. . . . . u . H .. o o p . . y 4 . .9... I .- o.
. . ~ 4 _ . — g H .I ~. I ... I. o -
o > . . . — . - . . ... _ a . . o; I. 4
. .. . . n > I I W
I 4 _
IIIIIrI I II 4 . q 4 . . a. . I. 4 I A 4
g H . . . . . ~ . o . g I a . ‘I
. . . ~ . . - .. . n . o o I o o . I
. H . . . o . . . . k . B 4 . .. . . . u u _
_ . I I '1 I-I.: In C IIIII II ... I 0.0 IIIAIIoolhII'III TIIIYI IL .IIIFI'IIIIIIIIIIYIIIIII liti’llilolol'
v .A. II .II .fII oII IIIoIII I.. I I III. I. 4' Io I I III; :II ... V. IH .. v u i q:g . . ... .I . 7.! . H
. . . 4 . n I I . . o a o .
. . . . . M . . c 1. 4 u . ... . . . a _
. .
_ . _ H . _ . o a z o . _
. . F III I J < 4 I n 1.1
I o H h . . . I
H . II I
H . . . . .I I . o . v a . . .
. . . - . . . . I
. . . . . . _
. _ . . . . . . . .I n . . . .
. I II. a I. Ir'I II'.’ III OI OIIYII 3‘. III- ''''' £II- IIII‘IIOIOAII‘O'J
II...II II ..III. I... ... .II..I.II.4 IIIIIIII I ...... .II..4. ....... I... III II . :IAI.:I.4I-I : III I 4 In” . M a 4 w .. I .
D 4
. . . . H . . r e o. n . . o a 9:. .
. H I n . . . . . I. . a a. . H .I no
. . . . > . H
. II 4 4 I
0 I I . h . ..1 . m . I I.. . . .
. . o n . “I! — o ... o. . .
a . . . _ . . . . I _ _ n . .. . o.
. . _ . . _ . o 1 . . o . .. L w w
u - II III- IIlB I I IIII| 9IIIII7 Clo-Ito! :.II.|0II|IIIIII'I III’IIHII IIOI TI'II I‘II : I
I N I I . I: III I I I I “I . I. c I l I I I A III I e uOI A o It. I II II I . I I III I o I: I I III I” II J o ”IV I . . 4w . . . IIIIH. . _
. . . v . 1 I t . . o _ I . a c
4 w . . _ _ _ fl 8 u“ . o . 4 . I” . H
. o 4 L qr . . .
4 d o . . 4 fl . I.-
. . . 1 . . 4 . ..V . ..
. . . . . . . . H . _P . . . . - H .4
. . . . . I ._ — I H . . . . . H
H I . . . III I lIL IOIIOII II'IO‘I .IOIIIII IITIIIJI'I'II*.'II IIIIII. IIIIL IIIIO IIIIIOII . I I
4 o It I I I . II. a II I II I I I a u l I I4 o I I III II I IIIIIIA I I I, II II. . g . . _ . .u . fl
. . . . . _ . . 4 T . _ .
. . 4 . . . . . 4 4 . . . . . . . 4 .
. . . . . . . . . . _ . _ 4 . .
. . I I . I ’* pl
_ _ . - . - . I .
. o _ _ . + . . I. H
. . . . . . — a . I . . . . .
. . h . . I . . H . . . . p . . _ ... ..- 4
. . . . . . . o . . - . .- . 1 .. ..
. I I L I! I7.“ I‘ I
H I b I. II .III I. To III I III IYIII: ..I..III.-I IlIIkoIoIoIIL IIIIIIIIIIIL I IYIII- VIIIoorIIII HIIIIIIIIIIIIIJwIIIIIOIWIIII; II “I‘lIIIIIIIIwJII t H I“.
III 0 I I III . . . . . . .
u u 0 I. I I. .
H _ . . . . . . . . . .. .m H I 4 P
. . r HII . r I” I: I I a
I. I . .I . J. . ., . A... .I. ..m .4 . - .-
. . .. .. . .
. . .k . . . v
. . . _ 4 4 . . . _ . . .-.: .. 4 . 4
~ u v u * < . I 4 n O . o n.. a Q o
. . . . 9|: IIIIQIIIIIIAVIIIIQIIII VIIIIIOIIIIIIATIIIII‘IIIIIIFIIII ..III. IIOIIIII'IIIIIIII.III;IIaI1I9IIQI¢IIIIIIIIHTIIIIIIQIoiII‘l10IIII
IIOII III OIII III OI II. I I I; OYIII I II IO‘O .VIuOon‘O I IIIO7 A .I . o . .. .I a c o . .
. . . . I . . .I . . . . . 4.
m . ~ . o . . . o H . H _ ...C . o o.
. . . I a .. . . . .
. — . . . . . .. . H
. . . I .. 4 4 4
1 I 4 o o 4 . a .I o ...
. . . . 4 . 4 4 . . . . 4. . _.
. . - .. <
4 . . a . o . a a . .... I
. . . . . . . o . .. . . . . . H . .. .
. I . . . ~
. . . . . .. I . . I VIOIIIII III,7II|II'III III III- {I III‘I’O'ITIIIOIJJIOOOLIIIIITII
.OI IIIJ III-I II“III .o IIII-III.T‘I Y.I IIIIIIIA IIICIIOQOII. 00:14 IIIIIIOIOOIIIAYIIIIO‘VI OIIAIIIIIIIII. IIYIII'I IIII I01. . H IIHI. i . 4 H _ ...
. m . . c . H . u . g H o 4. . . c . . uT
. u . . . . p u . .. 4.. A . a... . . . .
o . o v . . . H o I . I . . . . . I» I .4“ w.
u . o . . o n r .
y K I II .I . I l‘ .4 4 H
.I . . .. . I . . I H ...
. . . . I. o . .I A
. . . o . . . . . . o o .. M. H
. . o . . . o . . .. .... I
o . o o . o 4 v- V
III I e I I I Y 1.0 - III? II 0 IA 7 10-0 0 III. . I i QII III I I 009...! I . . IIlOII‘IotIAYII IC'OI‘I I III- 7 oIIIOIIIO 7.71 I YIIIIIII IIII| I .. . A . . I
o . n o . . 0 ¢ :0. .u a v
. . . _ . . . . . . . H. ... H. . 4
C 0 fl .
o IIIH
I H H r . ... .... . u I
- ... II. . I . . y . nu . . H. . . . Io ...... I
. ... .... I:.H . . . ... .I . . H .
.. . . . -ov. . . . . _ .. .-.; .... 4
4 o. I . ..v; e g . 1-..-7:7 4
..I. 9 O I|1 OIIICIIIIA I IO’II‘+II C III II o...:. IO- QIII' vICIOlOOIOIIII . . . .I a I . o ..I._ 9‘
_. ..III 0. ~ _ o _ o . I.4I<. ... .... 9‘
III a. 4. _ .~ . . _ . .I o L . - . .4
...I.. I . . a .. . o . . .. I. M. I . .III . I.
. .. . .. . _. . . . m
J I I .. o. u . . . «-
. I. . . . .H. .. v . . 4 . . .. . .
.I . . . . h . . . . . . . .9 . I
I. . . . . . . .. I . .
. .. . . . . . . . . III- -IIIIIII IIIIIIIIIII-IIILI
. I I Iv I IIOIOIA : I I I I 0.. o I. I I l V O . u I 4v. 5 II. 7):, ..- . I 4 II 0‘ I I I It. I I I A-- IIC‘II. I1 . u e
. n _ . . s . o I. o. ..
. . . . . . . . .. . o I I” .¢
. o o _ . . . . H4. . . M . .
. . . . L 3 - . 4
- I r . ; .. . .. . .
. . . . _ . p ....o . v I». .0 n
. o . e o o a H. . II . r. o . v .4
. _ . c . H . o H . a I H . H. . .
. _ ...
v: I_< 1' I'II. QIOOI IV I. all 'lII. . 7 o. I III... I. .Ivlo II. . ”I. .I‘ ‘IOIOI 'll'..-‘ . ..
. . . _ o o .I e I
. . M . . ” H . I HIMI . u. JII. .. o .I
_ . . . . . . . 41.. u... 9;
. . e To... I+Io
4 .I S w

 

 

 

 

 

 

  

u c...c.rr..z ... b.

 

 

 

 

 

 

 

“4. .
:9- e...
m

I

 

 

 

 

 

 

 

- 48 -

in the shorter carburization periods may be explained by the fact that
the carbon did not diffuse at an even rate. In some instances the car-
bon content reached full eutectoid composition before any further appre-
ciable diffusion would occur. This may be noticed especially in the
sample carburized for a one hour period. ‘Very little diffusion has oc-
curred past the eutectoid zone. In the sample carburized for two hours,
it will be noticed that the diffusion depth is greater, yet the carbon
concentration in the case is much lower. This may be due somewhat to
the nature of the carburizer, the quantity of carburizer in the bomb,

or to the surface conditions of the steel.

Figures 44, 45 and 46 show the hyper eutectoid, eutectoid and hypo
eutectoid compositions of the sample carburized for eight hours. The ex-
cess cementite can be seen in the grain boundaries of the hypereutectoid
zone very plainly at this higher magnification used. This is not appar-
ent in the photomicrosraphs taken at lGOX. The pearlite may also be seen
to be a distinct lamellar aggregate of ferrite and cementite. The pear-
lite in the hypo-eutectoid photo, however, shows that the pearlite is
tending more toward the sorbitic form. Figures 47 and 48 show the eutec-
toid and hypo-eutectoid structure of the sample carburized for 3 hours.
These photomicrographs are likewise taken at a magnification of lOOOX.
The pearlite is again well defined in the eutectoid zone, but is in more
Of a sorbitic nature in the hypo-eutectoid zone. Figure 49 is a photo-
Inicrograph taken at lSOOX of the sample carburized for 1 hour. In this

Case the pearlite tends toward a sorbitic form.

- 49 -

 

    

  

I; A} V.
‘.-. ‘ l/
'4 )HW'"

   

Figure 44
HyperbEutectoid Zone
Case Carburized 8 Hours
at IVOOOF.

     
 
 
  

I
‘\l

"L1.
“\

 

F" 1:31.313. {1"} '

‘3 ,§\\\\x§‘x;fm\\) 9: L ' - ' Figure 45
“V'-:fi(j$33 (2,5; f"z- ‘ Eutectoid Zone _
}»”»»w&LC ;..£;'J1 3] Case Carburized 8 Hours a 4
w at 173331;- r

"\'|\
\.
:-_-
v .3.
\v"\).\
. \‘n .-

x3:

    
 
 
   

Figure 46
Hypo-Eutectoid Zone
Case Carburized 8 Hours
at lVOOoF.
Mag. lOOOX

 

"7"?" ‘5“.5. - .... ,

‘ ' 3' '3’"
I
r

I

~ .1

-50...

   

Figure 47
Eutectoid Zone
Carburized 3 Hours at lVOOOF.
Meg. lOOOX

 

Figure 48
Hypo-Eutectoid Zone
Carburizec 3 Hours at l700°F.
Mag. lOOOX

Figure 49
Eutectoid Zone
Carburized 1 Hour at lVOOOF.
Mag. 1500K

l.

2.

COJCLUSIONS

The effect of carburization on the critical thermal
range as measured with a dilatometer, is a resultant
dilation effected from the zones present. The great-
er the depth of case, the greater is the tendency to-
ward a single eutectoid type transformation. Carbur-
ization periods of 6, 7 and 8 hours reduce the trans-
formation range to a minimum of 30°C. The normal
range for the non-carburized sample being 100°C.

(S.A.E. 1020).

The rate of carburization is retarded appreciably

after a 6 hour period.

Non-uniformity in carbon content of steels may cause
erroneous critical point measurements when measured

with the dilatometer.

 

 

BIBLIOGRAPHY
l. "Metals Handbook": American Society for Metals,«

1939 Edition, Cleveland, Ohio.

2. Sauveur: "The Metallography and Heat Treatment of
Iron and Steel," Fourth Edition, The Univer-

sity Press, Cambridge, Mass. 1955.

3. H. E. Publow and W. P. Fitzéfiandolph: "The Micro-
structure of Hardened Carbon Steel," Bulletin

No. 45, Michigan Engineering Experiment Sta—

]“77‘13‘41 Té:m. ”-92 a .' '
r

tion, April, 1932.

. U . . u . .. . 1.. IA . - ‘ «...-r0 . 1...: .. ..
w ...... 4-4...\.IS-J.VM . \an .....Bu...’ . ... lute. fi_rw...‘. .. .1.“ . -..: .
y . . 1.. it- .1. 1 a \Ql. fi‘VF' . k u. 2 .. u y ‘ In
. 1:. 11‘ . . “8'4..m.k . .. . ‘ r...($\ NJ? I. l, .I‘ . if? . h. ah~ . h. . ,
I. . . . . . do ‘ ... . . . . ‘ . 0.10 .h ..

 

 

 

A
‘t’

_ ...—”Che“

..e .w.
\ at

h,
,H . -.
v .
i
V 1 ,
,
"—M‘-‘ V,‘

. .
L. 4
d‘

" {Oi-.‘ol

.......... o. SJ. ..7: 1......

 

0 I

I

v'QJ

t

n; -
,\_- .-

P

I .

I r '

_ .j'fgx."

l
O

.I _‘
.‘ 5" vv -
' 1' 'l-
- '5 ~
- ‘ ‘U;y' A I
‘ l

A

.
......

_. I - ' IARI’4 .‘A.
3 don”t):

I .

”A
' ' +wa
"xii

1;er

   
        
  

D
l “A. q
—.

11"“ .
" d»

a 4

.6‘

  

2“; . 2": ‘ . _ . A Mfg ' -¥ _ g - ' .
of: -t (g- ... V I ..v 3,, 4 :-'-. {”539
" f... .- A3 ' ...-1'11”“ -. " I -‘ ‘ --.; 3" ‘Vm' ' -
_. ' ' ’ . 7.. ' h. ._ ' ..' . .' o ..f V‘ ‘ I “ I '. ‘ 3". 4 ‘h. I ‘ . ' "r l' *3 J A' a.) ,." ' I C. " ' : ‘
. i .‘ . . - .- , _ ... v' 3 ._ ... . T ‘ nr_.‘.v_ « - , .
. II .V. ’ ... ‘, ‘ . :: .‘- ‘ ‘ '. J ‘ A" II’.‘ ‘ ' ..' '.'."'“ > ' ‘ ; ' "... J' u ._ ." ' ' .1 3' " ...! I, ', . . I. o-‘
a ‘ y ' ' ..‘I ‘ ', ‘. f , .‘l': ‘ - - ' 4 ‘ ' '. 1. _.‘. ' ' I- ‘41 "' . V f
A '_ . . . ‘ - 2 '0 - '-‘.‘ ' ' ' .- ' ' ' .'.' . ."' o _
.' ' ‘ ' o -. ' 2 I, - ' i L'. ' ‘V -‘ '
‘ . . i.“ ' ‘ ~ .‘ . -- p ' ' u ‘ '. »' . ‘- 4’._ u ‘ ;
- . .. 1 _ . . ' . ' ' ., .- ; _- — -_ ‘ 4‘ ‘ 0-. V . . A o
-. __ J. _' ' Ld': ‘ ‘V ' '

 

I
' .
J
O

‘ .
I

   

*2:

4
.-,Ar

' +‘lr.\:

'I. "VI...
.‘ .. ’

'9‘ $5435 51" . . c - --
.. M“
sac “

I ‘3 .
m; _ }

.7
l- .
IQ.
LS},

f
h

.9! _

  
      

 

 

  
  
 
 
  
    
 
  

  

a

.141'3ANSTATF LerFRSITV 1111'? ‘fF‘S

ll ‘
0

1
I
174 572