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2,448,753
Patented Sept. 7', 1948
' UNITED STATES PATENT OFFICE
QHEA'IKTHEATI‘NG AND COLD-ROLLING
.HAIDFIEIJDIMALNGANESE STEEL
‘Carl W; Weesner, ‘Warren, Ohio, and Wallace B.
,
Lél’fingwell; ‘Sharon, Elvan .R. Babylon, New
Wilmington, 'and'Homer'L. .Schell; Sharon, Pa;,
assignors‘to?h'a'ron SteelUorporation, Sharon,
‘Pas a'corp'orationofiPennsylvania
.NoiDrawing. Applicationlibecember 16, 1943,
Serial No. 514,548
2
1
The invention ‘relates ‘to :the 'manufacture'of
the “frosty” surfacev embrittlem'ent’is the result‘iof
manganese'steel strips and" the'ilike; andv more
In most steels, lowering the carbon ‘content
particularly to‘ the‘ manufacturep‘f: thin fgauge,
tends ‘toward ‘softness and ductility,‘ 'but‘f-Had?eld
cold rolled; high‘ manganese, ‘high carbon‘ steel
strips and the like ‘adapted 'toiheuse'd'iamong ‘5 steel behaves in a‘ ,contrary'manner; v"'I‘he‘duc
tility of Had?eldst'e‘el when pr'esent’isdue tjo'its
other‘ purposes ‘i or ‘making helm'etsff'or the ‘armed
austenitic composition. vWhen the-carbomcon
forces.
tent
{is "considerably ‘lowered; ‘the 'highmanganese
Helmet steel must'be soft, ‘ductile-and‘ have-deep
austeriite
is no longerstable on cooling, but-tends
drawing qualities‘ in‘ order that‘helmets may-‘be
properly formed or drawnto' the 'desiredshapei :10 to'decompose, probably ‘forming a'brittle mixture
of epsilon and alpha'iron.
»
from high manganese "steel. High manganese
"Unfortunately, it is_ hardly~possible~and not
or “Had?eld” steel, th‘atisgsteel ‘containing‘irom
practical in the - commercial ‘manufacture Y of thin
10% to 20% manganese an‘d'from'1100'% to 150%
gauge high manganese, v‘high;carbon‘s‘t-ritvsteol to
‘decarburization.
carbon as thin as .044 to
'
'
‘
.
inch, an'd'co'ld
rolled and heat treatedis ‘admirably ‘suite‘dfor' ‘~15 recarburize material .which'l‘has'b'ecome decar
‘b‘urized‘, in order torcorreot 'theponditionsifourrd
such purposes. However, extreme‘ difficulties
to ~> exist, as-shown by ‘recarbur-izatiow off-samples
have been encountered'and considerable‘ dam
in-labor-atory‘tests; so‘ itbe'came-fabsoliitely essen
aged or scrap' material rh'asqb'een‘ made in“ ‘at
tia'l‘to ?nd some ‘way in‘ rwhichyvtheideoarburiza
tempts to manufacture-such material.
Some of these ‘difficulties and“what is ‘bellevedi “20k 'tioniduring heat treatment could berelimirrat'ed.
The normal heat treating cycleufor‘ Had?el'd
to be the explanation-of ‘the-"causes of the “same
are set forth in the copending Wee‘sner‘and‘Iief
steels includes heating the . steelito ‘a itemperature
above the upper critical .po‘int, approximately
.1800“ F.‘ to~1900° :F. and usually{about-1118509!!!"
inventions describ'e'dlin sai'dT'Weesner andiLet?ng- 25, ‘and then-quickly cooling the :same, .as ss'etztorth
insaid Weesner and Lehingawelll patents.
well patents are directed more particularlyto
We have discovered ‘that Had?eldzsteel :re
ways and means :of .reclaimingprsalvagingsuoh
?ngwell applications Which-‘have mature‘d-ashPat
ents Nos. 2,368,9525'v and>2,410;3T212i Howeveiythe
sponds» .to‘zhea‘t treatment: extremely :rapidly' and
that thet'steel is ‘completely ‘austenitizedazalmost
or elimination ‘of the conditions Which?apparen't- 30 instantaneously upon being ,heated' towaaeliigh
temperature of from ‘1900" vF; to, 20.00“ 21?..3and
ly cause the material to be‘ damaged. duringlthe
damaged high-manganese strip‘ material.
The present invention involves the avoidance
cold rolling and heat ‘treatment thereof." ‘Thus,
the dif?culties or‘ damage-apparently-\arevcaused
in part by - surlfa'ce :embrittl‘ement iresultlng" ‘from
.
decarburization.
‘
In our early attempts-at cold-rollinglandiheat
treating \Had?eld strip two conditions wereiiound
associated \with low rductilitye-?rst, :oarbid'erpre
cipitation at "grain boundaries, and, second,
preferably from 1950“ F. to 2000“ Frintav?umaee
in ‘which the temperature is maintainedrim the
hottest'lzone at‘ approxiniately??o?trF;:r andrthese
furnace and steel‘ temperatures ».are- materially
higher than ‘ those :‘previouslyiusedwforwheatxtmat
ingpl-lad?eld steels.
‘
We ‘have ‘further discovered that-tthe extentrof
decarburization occurring inv'l-lad?eld steel; which
“frosty” ‘surface, .i. e‘. the-:fros'ty appearance ire- ~40 is the-cause of the dimculties; is proportional to
time and that if the steel is substantially -in
sulting from innumerabiesmall cracks ‘developed
by the ‘Olsen ductility ‘cup test.
We discovered that the-icarbide"precipitation
.stantaneously completely .austenitized .by .ex
. tremely rapid heating tot‘ne-high tempe'ratureof
from I900° F. to 2000° Fpand- then immediately
, .dif?culties ‘could'abe controlled lbyea lverylcareful v
control of. the‘ cooling or quenching 'stagero?ithe ‘4 quenched, insu?icient time elapses for any .ap
"preciable amount of ‘decarburizati‘on to .occur.
heat treatment :step.
‘It is’ therefore possible by 'heatingand; quenching
Tests maderevealedr-thattheiirostyisur?aceiwas
at high "speeds, that ‘is by ‘carefully "controlling
accompanied :by decarburlzatio'n. ~ :Samples
the time ‘and temperature of "heating, ‘to hold
known to be frosty and decarburized: were-re
l car-burized and heat treated .verylcarefullyfnnder 50 'sur'face‘ vdecarburi‘zation of Had?éld steePto-"Sueh
a minimum that no harmful effects result.
controlled laboratory conditions and" TbhBlIi'hEStEd.
‘After the rec‘arburizing- ‘:heat treatment,‘ the
,=frosty condition‘disappeared andth‘e ductility-'ras
We have further discovered that the su?-a'ce
“appearance rof cold .rolled .‘h‘eat itreatedililad?eld
steel is no reliable index as touthepresenoe :Ior
. determined bythe-Glsen cup-test, wasimaterially
increased. Thus, it was ‘?nally ‘determinedithat i55 absencewof ‘surface decarburization cor :embrii';tles
2,448,753
3
ment.
4
If the heat treatment is carried out in a
highly oxidizing atmosphere, there is a tendency
to scale and "burn” the surface of the Had?eld
steel strip at the same time that the decarburiza
tion and surface embrittlement occurs. Contin GI
ued heating of Had?eld steel in a non-oxidizing
neutral or moderately reducing atmosphere will
produce a decarburized and brittle surface with
out appreciable scaling or marring of the sur
face. Thus, a good surface does not necessarily
indicate good ductility or the absence of decar
burization and surface embrittlement. Contin
ued heating in a very reducing atmosphere, how
ever, produces very little surface decarburization.
Test samples made in the laboratory from the 15
same material were heated for 5 minutes at 1950°
F. in three different atmospheres, water quenched
and tested.
The ?rst sample was heated in a
highly oxidizing atmosphere and when tested had
a .390 Olsen cup test value with a “frosty” con
;dition. The sample also had heavy decarburiza
tion with a rough surface, burned and scaled, and
and the like more quickly and more cheaply than
it has been produced previously.
These and other objects may be obtained, the
stated results achieved, and the described di?i
culties overcome by the methods, steps, products,
treatments, and discoveries which comprise the
present invention, a preferred outline of the
steps being set forth in the following detailed de
scription, and which are particularly and dis
tinctly pointed out and set forth in the claims
forming part hereof.
High manganese, high carbon strip steel of the
“Had?eld” type is hot rolled down to the thinnest
possible gauge to which it can be rolled without
damaging the strip or hot mills, which may be
approximately .109 inch in thickness, and the
strip is then coiled and cooled in water as rapidly
as possible to prevent carbide precipitation and
decomposition. This cooling step following hot
20 rolling is a departure from usual methods which
do not ordinarily include such a step in connec
tion with the manufacture of hot rolled strip.
The hot rolled strip is then continuously heat
to take the carbides back into solution
ly reducing atmosphere. When tested it had a 25 treated
and to render the steel fully and uniformly au
.390 0lsen'cup test value with a “frosty” condi
stenitic. The heat treatment is performed in ac
‘ tion. The surface Was heavily decarburized and
cordance with the discoveries of the present in
brittle, butthe surface appearance was smooth,
vention by substantially instantaneously com
very brittle.
'
The second‘sample was heated in a moderate
The third sample was heated in a very reduc
pletely austenitizing the steel by extremely rapid
ing atmosphere and when tested had a .440 Olsen 30 heating to a temperature of from 1900° F. to
cup test value with no frost. The surface condi
2000° F., preferably in the latter half of said
tion was smooth, there was very little decarbu
range, followed by immediate water quenching;
, rization and the sample was ductile.
Thus, the heat treatment of 171/8" x .109" and
Therefore, the character of the furnace atmos
of 15%" x .109” hot rolled “Had?eld” steel has
phere during the heat treatment is also an im— 35 been successfully accomplished in accordance
,portant factor in addition to the control of the
with the present invention in a 25 foot continu
time and temperature of heating. Unfortunate
ous heating furnace in which a non-oxidizing,
ly, in mill practice it is not feasible to maintain a
neutral or moderately reducing atmosphere is
highly reducing atmosphere in continuously
maintained, and in which the furnace tempera
, heating cold rolled Had?eld steel strip as rapidly
as it is necessary to do so followed by an imme
ture is maintained at or above approximately
2000*’ F. The effective interior length of this fur
diate quench. For these reasons, it is only pos
nace is approximately 23 feet and the hot rolled
strip having the widths and gauge stated have
sible as a practical matter to control the furnace
atmosphere such that it is non-oxidizing, neutral
or moderately reducing, which can ordinarily be
readily done in the operation of fuel ?red contin
uous heat treating furnaces by a proper control
of the burners and of the fuel air ratio. When
the furnace atmosphere is thus controlled, and
45
been run at from 9 to 12 feet per minute through
the furnace. The strip reaches a temperature
close to the furnace temperature of approximate
ly 1950 to 20009 F. at a point approximately 2 feet
ahead of the furnace exit opening. The strip is
then water quenched as quickly as possible by
. when the heat treating is very rapidly carried out, 50 passing it into a water quenching bath imme
little if any surface decarburization, burning or
diately as it leaves the furnace.
scaling occurs.
As previously pointed out, the cycle of the ex
‘Accordingly, it is an object of the present in
tremely rapid heating followed by an immediate
. vention to provide a method of manufacturing
water quench occurs so quickly that there is no
thin gauge, cold rolled, high manganese, high 55 opportunity for surface decarburization of the
- carbon steel strips and the like Without surface
material to occur.
'
decarburization or embrittlement, so that the
The strip is then pickled in an inhibited sul
normal ductile properties of austenitic manga
phuric acid pickling bath, preferably an aqueous
nese steel may be obtained.
solution of about 10% sulphuric acid by weight in
A further object of the present invention is to 60 Water operated at a temperature of about 150° F.;
provide a method of making cold rolled, heat
and the strip is then water sprayed, washed,
steam jetted and dried in a hot air drier.
I treated, high manganese steel in accordance with
strip practice cold rolled to gauges as thin as .044
We have also discovered that the pickling step
_' to .033 inches in thickness.
‘ _'Furthermore, it is an object of the present in
vention to provide a new method of manufactur
65
is somewhat critical and particularly the pickling
temperature, because “Had?eld” steel burns or
pits at a higher pickling temperature and the
drying step is necessary to prevent rusting and to
eliminate hydrogen for preventing hydrogen em
ing cold rolled, high manganese steelstrips and
the like by which the resulting product has a
good surface appearance, extreme toughness and 70 brittlement.
The strip may then be cold rolled from the
strength, and high ductility and drawing quali
nominal .109 gauge down to .075 to .080 gauge
ties.
(31% to 27% reduction, or about 27% reduction)
And ?nally, it is an object of the present inven
tion to provide a new method of making cold
on a four stand tandem cold rolling mill; Other
rolled, light gauge, high manganese strip steel 75 ‘ types of cold rolling mills, however, may be used.
The above operations of heating or annealing,
2,448,3258
5i
quenching. pickling ‘and cold rolling‘:- are then
fully? austenitic manganesemsteel'gi andrzwithout
repeated to.reduce ' the 1 strip ' from-1.075 to. .080
, gauge .d-ownfto‘ .050. to: .055: gauge; and again‘ to
surfaces"decarburizationsor rembri'ttlementz.
Having? newt-‘described: theafeatures; oftthe': in‘
reducethe' strip from .050 to .055 gauge downi'to
.044ito. .048 gauge to makethe ?nished cold rolled
ventiom: an ‘embodiment :of; steps l by-iiwhich the
inventionr- mayrbeecarried’ tout, ‘ the: ‘advantages
material‘; or: even'againto reduce the strip from
and "results . attained by._:the:ainvention~,i and. the
.0441‘to .048vgauge down to .033 to .038 gauge fin
new‘ discoveries‘?maderiin: connection with the
treatments of and-cold rollingrof high-manganese
The-"?rst intermediate ‘anneal after the mate
steel; the. new" and useful: methods, steps;v treat
riallhaslbeen: cold‘rol'led to from‘-.075 to “080 10 ments,. arrangements; and-‘products, (are set vforth
ishedimateriala
-
in the“ appendedf'claims. Y'
gauge is carried out with a strip speedthrough
the annealing?furnace described of: about‘ 12. feet
We claim&*
a
.
.
1.‘ The;v method of ' producing; strong 1 metal
penminute; the secondintermediate anneal or
sheets .: of: hot-rolled -. Had?eld f-manganese- steel‘,
heatitreatment."is..:carried out at .a stripspeed
through thefurnaceo-f about 18 feet per-minute, 15 which: comprises; giving :the. hot~rolled sheets an
austenitizing treatment; by heatingpthem ‘to about
the.‘tl1ird "intermediate anneal is carriedout at
1900‘?
waterl-quenchinggthem ands-cold
a strip speed of about 30 feet per minutaand the
rollingithe austenitized sheets; toabout 27%‘wre
lais'tiiintermcdiate Ianneal.‘ is ‘carried. out‘ at a
speediof. BOJKfeetperm-inute or higher;
Thus; inieachr instance,‘ the heat treatmentris 20 ‘2;:- Tlretmethod-r ofurn'aking coldzrolled Had-?eld
manganese steelr-stnipailess than,0.109!=' in thick
carriedir-out; in.» the shortest possible time ‘at . the
ne's‘sl, having,- a‘ fully and; uniformlwaustem'tic
fastest possible rate. of. heating; and the quench
isaperform'ed as? quickly as possible after leaving
structureewith‘ carbides in .so-lutionrand being
free‘ of surfacei:decarburizationrand~ embrittle
the heatutr'eating. furnace.
‘
The heat: treating, ‘operations. in each. instance 25 ment-;- which comprises; completely‘ austenitizing
0.109’? thick‘. ihot -. rolled iHad?eld manganese steel
are: controlled‘ to. accomplish several results: ?rst,
strip »bynheatingthe-strip: as it moves continu
to? recrystallize the cold rolled structure, ‘second,
ously-through a furnace‘to aistripi temperature
toxkeep: the. carbides: in. solution, and third; to
ofx19009 Fbto 2000°
then before su?icientitime
prevent:- surface decarburizatio-n or embrittle
has elapsed ‘ for - the i-occurrencei of 'surface decar
merit‘. The-heating to the high temperature be
burization" quickly; water quenching the continu~
tween 1900913‘. and2000° F. recrystallizes the cold
ously ‘moving; stripimmediately as ita'leav-es the
rolled-structure, theimmediate Water‘ quench
furnace, to» keep» the» carbides: in: solution, and
ké'epsrthe‘r'carbides in‘solution, and the rapidity
then: cold rolling. the .strip..down. to 0.0575’! to
of. heating. and quenching prevents. decarburiza
ductiom:
tion'; The resultingmaterialis fully and uni
formly austenitic with carbides in solution, with
the cold rolled structure recrystallized, and with
out; any. objectionable decarburized surface
layers.
"
We have discovered that‘if for some reason the
.
_
.
0.080,“ thick strip“
3.,» The 7 method : of -.making cold {rolled Had?eld
manganese :- steel: strip ,gless- than» 0.109 '--’ in :thick
ness; having a. ¢fully;,.,and ‘uni-formly‘ ‘Y austenitic
structure :with carbideshin solution,‘ and being
free of _. , surfacer-decarburization and; - embrittle
ment; which comprises, completely austenitizing
heat treating operation is slowed down, for in
0.109” thick; hot rol-ledI-Iadfield manganese steel
stance, because of~some failure of equipment, or
strip by.“ heatingr-thetstrip. as: it~moves1 continu
of: the necessity vof stopping the line'for welding
ously-‘through a: furnace to aestrip temperature
one coil to another, thus permitting portions of
the strip to lie in the furnace, these portions will 45 of :1900" Fwto 2000? R, .then -_bef.ore sufficient time
has elapsed for‘ the occurrence; org-surface decar
have badly decarburized surfaces and these por
burization quickly water “quenching/i the < continu
tionsvmust be removed. However, the material
ously .moving strip ‘immediately: .as~wit- vleaves the
therein may be reclaimed by treatment such as
furnace-to keep the, carbideslin' solution, then cold
describedzirreither of the Wee'sner and Lef?ng
50 rolling-the "strip; down: toy-i 0.075” to 7.0.080? ’ thick
w'ell companion patents referred to.
strip; and» then’ repeating-the: beatings quenching
While the-process and product have beenide
andiacold: rolling ,operations until i the strip
re
scribed in‘ connection with the ‘manufacture, of
duced 117010.044?! to:,0.033" thickmaterial. '
strip steel: or stripsheets made in accordance-With
Ii; The :methodi of:v making :cold rolled» Had?eld
strip practice, the, present invention is also ‘ap
plicable‘ to the manufacture of other high man 55 manganese steel“ strip ‘ having a a ‘fully A and uni
formly; austenitic-i-structure‘ with" carbidesv in
ganese steel... products such as sheet steel, in
solution; ' and. being; free of.‘ surface decarburiza
accordance with sheet practice.
tion,; and-~embrittlement; ...which'> comprises, , com
Accordingly, when the term “strips” ‘is used
pletely . iaustenitizingi ,Ha'd?eld' ‘' manganese ‘ steel
hereinland-in-the appended claims, the term is
intended to include the manufacture of cold 60 strip: by» . extremely r‘: rapidly. heating; the is strip; I as
roiledihignmanganese steel. strips, stripsheets,
it ‘ (moves continuously;.v through a ' furnace- tov ‘ a
strip: temperature? of. ‘19501°~'F.-~ to 120009 V F‘-, then
sheet-s? wire and- the. like.
before- su?iicienttimechasr. elapsedrfo'r'theiioccure
Also, when/the term “high'manganesesteel”
rencetori surface decarburizationr' quickly: water
is referred to herein, it means steelslof'the “Had
?eld” type, which generally contain from 10% to 65 quenching the continuously moving strilrrimm'ei
diately as ithleaves the furnace to keep the car
20% manganese and from 1% to 1.5% carbon,
bides in solution, and then cold rolling the strip
with possible additions of small percentages of
to about 25% reduction.
other alloying elements, such as nickel and
5. The method of making cold rolled Had?eld
chromium, which sometimes are added to “Had
70 manganese steel strip having a fully and uni
?eld” steels.
formly austenitic structure with carbides in solu
Thus, the present improvements and discov
tion, and being free of surface decarburization
eries provide for the ready and economical man
and embrittlement; which comprises, completely
ufacture of high manganese steel strips cold
austenitizing Had?eld manganese steel strip by
rolled to gauges as thin as .044 to .033 inches hav
ing extremely high ductility characteristic of 75 extremely rapidly heating the strip as it moves
2,448,758
7
8
continuously through a furnace toa strip temé
9.‘ The method of making cold rolled Had?eld
manganese steel strip having a fully and uni
formly austenitic structure with carbides in solu
perature of 1950° F. to 2000°'F., then before suffi
cient time has elapsed for the occurrence of sur
face decarburization quickly water quenching
tion and being free of surface decarburization
the continuously moving strip immediately as it 5 and embrittlement; which comprises, hotrolling
leaves the furnace to keep the carbides in solu
Had?eld manganese steel strip tov the thinnest
tion, then cold rolling the strip to about 25%
possible hot rolled gauge, then rapidly water
reduction, and repeating the heating, quenching
cooling the strip, then completely austenitizing
and cold rolling operations until the strip is re
the steel by extremely rapidly heating the strip
10 as it moves continuously through a furnace to a
duced to 0.044" to 0.033" thick material
6. The method of making coldrolled Hadfield
strip temperature of 1950“ F. to 2000° F., then
manganese steel strip having a fully and uni
formly austenitic structure with carbides in solu
tion, and being free of surface decarburization
before sufficient time has elapsed for the occur
rence of surface decarburization quickly water
quenching the continuously moving strip imme
and embrittlement; which comprises, completely 15 diately as it leaves the furnace to keep the car
austenitizing Had?eld manganese steel strip by
extremely rapidly heating the strip in a non
hides in solution, and then cold rolling the strip
to about 25% reduction.
7
oxidizing atmosphere as it moves continuously
10. The method of making cold rolled Had?eld
through a furnace to a strip temperature of
manganese steel strip having a fully and um
1950° F. to 2000° F. to substantially instantane 20 formly austenitic structure with carbides in solu
ously obtain complete austenitization of the steel
tion and being free of surface decarburization
at said temperature, then before suf?cient time
and embrittlement; which comprises, hot rolling
has elapsed for the occurrence of surface decar
Had?eld manganese steel strip to the thinnest
burization quickly water quenching the continu
possible hot rolled gauge, then rapidly water
ously moving strip immediately as it leaves the 25 cooling the strip, then completely austenitizing
the steel by extremely rapidly heating the strip
furnace to keep the carbides in solution, and then
as it moves continuously through a furnace to
cold rolling the strip to about 25% reduction.
7. The method of making cold rolled Had?eld
a strip temperature of 1950“ F. to 2000° F., then
manganese steel strip having a fully and uni
before su?icient time has elapsed for the occur
formly austenitic structure with carbides in solu 30 rence of surface decarburization quickly water
quenching the continuously moving strip imme
tion, and being free of surface decarburization
diately as it leaves the furnace to keep the car
and embrittlement; which comprises, completely
aiu'stenitizing Had?eld manganese steel strip by
bides in solution, then cold rolling the strip to
extremely rapidly heating the strip in a non-ox
about 25% reduction, and then repeating the
idizing atmosphere as it moves continuously 35 heating, quenching and cold rolling operations
through a furnace to a strip temperature of
until the desired cold rolled gauge is obtained.
1950° F. to 2000° F. to substantially instantane
CARL W. WEESNER.
ously obtain complete austenitization of the steel
WALLACE B. LEFFINGWELL.
at said temperature, then before sumcient time
ELVAN R. BABYLON.
has elapsed for the occurrence of surface decar
40
HOMER L. SCHELL.
burization quickly water quenching the continu
REFERENCES CITED
ously moving strip immediately as it leaves the
furnace to keep the carbides in solution, then
The following references are of record in the
cold rolling the strip to about 25% reduction, and
?le of this patent:
repeating the heating, quenching and cold rolling 45
UNITED STATES PATENTS
operations until the strip is reduced to 0.044"
to 0.033" thick material.
Number
Name
Date
I, 8. The method of making cold rolled I-Iad?eld »
manganese steel strip, less than 0.109" in thick
ness, having a fully and uniformly austenitic 50
structure with carbides in solution, and being
free of surface decarburization and embrittle
ment; which comprises, completely austenitizing
0.109" thick hot rolled Had?eld manganese steel
strip by extremely rapidly heating the strip con
tinuously during 21 feet of strip travel at from
9 to 12 feet per minute in a non-oxidizing at~
mosphere in a furnace to a strip temperature
of 190° F. to 2000’ F., then before sui‘n'cient time
has elapsed for the occurrence of surface decar
938,893
1,017,904
1,344,392
1,462,460
1,851,903
1,929,356
2,368,955
2,378,991
Potter ____________ __ Nov. 2,
Potter ___________ __ Feb. 20,
Had?eld _________ __ June 22,
Apgar __________ __ July 17,
Hall ____________ __ Mar. 29,
Janitzky __________ __ Oct. 3,
Weesner et al. ____ __ Feb. 6,
Franks _________ __ June 26,
1909
1912
1920
1923
1932
1933
1945
1945
OTHER. REFERENCES
"High Manganese Austenitic Steels,” reprinted
from “The Iron Age” issue of Oct. 1, 1942, Electro
60 Metallurgical (30., N. Y. C.
.
burization quickly water quenching the continu
“Alloys of Iron and Chromium,” vol. II, Kinzell
ously moving strip‘immediately as it leaves the
and Franks, 1940, pp. 289, 438, 442, and 443. ,
furnace to keep the carbides in solution, and
“Metals Handbook,” 1939 ed., pages 1133, 1134,
then cold rolling the strip to 0.075" to 0.080"
1135, and 568.
thick strip.
65
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