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Патент USA US3075848

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nite
3,075,838
"me
atent
1
Patented Jan. 29, 1963
This preferred alloy can vary as follows:
3,075,838
MANGANESE STEEL
Howard S. Avery and Henry J. Chapin, Mahwah, N.J.,
assignors to American Brake Shoe Company, New
York, N.Y., a corporation of Delaware
No Drawing. Filed Feb. 24, 1950, Ser. No. 10,557
2 Claims. ((11. 75-123}
This invention relates to manganese steel and in par
ticular to a standard 13% manganese steel so alloyed as
0,
Mn,
0.4
13.7
0.5
14. 3
Percent
Percent
Si,
Ni,
M0,
Percent
Percent
0.2
1.7
1.9
0.7
0.04
0.04
0.8
2. 3
2.1
0. 9
Max.
Max.
Percent
Percent
V,
P,
S,
Percent
Per
cent
10' Typical of an alloy within this narrow range is heat “24”
hereinafter which in round ?gures is 0.5% C, 14% Mn,
2% Ni, 2% Mo and 0.8% V. Following the conven
to be capable of e?ective precipitation hardening result
ing in yield strength values of better than 70,000 psi.
tional or standard toughening treatment (2000° F.~—2
and elongation of at least about 10%. This represents,
h0urs—water quench), to provide standard manganese
in comparison to the standard heat treated alloy, a sig 15' steel properties, aging at 1080“ F. for 8 hours hardened
ni?cant enhancement in yield strength achieved at a ‘sacri
alloy “24” to 262 BHN, raised yield to 95,640 p.s.i. and
?ce in elongation which is not deemed detrimental for
lowered elongation to 29.5%. Aging at 1200° F. for 2
hours gave a higher hardness (277 BHN), ‘a yield of
many uses.
~
" Manganese steel. is well known for the ease with which ~ 99,300 and 21.5% elongation. Eight hours at 1200° F.
it can be work hardened. Precipitation hardening is not 20 raised the yield, but elongation was unacceptable at 9.5%.
Aging at 1300° F. and 1400° F. for 6 hours also lowered
commonly followed. The practice, where followed, has
been to solution heat treat at about 2000° F. followed
by a quench or rapid cool to hold a metastable-austenitic
structure.
This preliminary step is the standard heat
ductility too far.
_
.
I
.
.
The following table sets forth data pertinent to three
_ alloys that represent the outside limits of carbon (0.7%) _
and vanadium (about 0.3%) under the present invention:
treatment for manganese steels as the mode of achieving
maximum toughness. After this, the casing is aged at a
TABLE I
temperature substantially under 2000° F. to precipitate‘
a hardening phase, but the associated. loss in toughness
attendant to such precipitation hardening procedure is
usually too great to warrant general adoption. While the‘
Heat
1
0,
Mn,
Per,
Per-
Per-
Per-
Cr,
Mo,
cent
cent
cent
cent
cent
cent cent
Per-
Si,
Ni,
v,
Per-
Per-
A1,
Per
cent
role of vanadium has heretofore been recognized in pre-‘
cipitation hardening, We have now found that the above,
speci?ed values of yield strength and elongation can be
attained in a precipitation hardened manganese steel by 35
AS CAST
combining vanadium with nickel, or nickel and molybde-i
num, provided that the carbon content does not exceed
Heat
about 0.7%; in fact, superior results are achievedvby
holding carbon within the narrow range of 0.4—0.5%;
Yield 1
49. 2
and furthermore, we- have found that vanadium is so
potent in increasing yield strength at a sacri?ce of lowered
Tensile 2
88. 7
49. 2
79. 4
49. 3
101. 7
ductility in a standard 13% manganese steel that its con
tent should be restricted to not more than about 0.9% in
Elong 3
'
RA.‘
BEN
.27. 5
33. 4
156
21. 0
29. 5
170
36.0
34. 1
207
., 2HOURS, \VATER QUENCH (W.Q.)
conjunction With the aforesaid carbon limitation; and so
44. 2
105. 9
67.0
47. 6
163
45. 2
109. 9
55. 5
42. 5
143
to do is the primary object of this invention. Another
47. 6
109. 1
61. 5
50.0
174
object of the present invention is to so restrict the harden
ing treatment as to assure the desired results.
HARDENED BY 1,200‘7 F., 2 HI(I)\IUGI)KS, VV.Q. (AFTER TOUGHEN
Exceptional results are achieved by limiting carbon to
0.4—0.5% and vanadium to 0.7-0.9%. The signi?cance 50
348 5 _____________ ._
71. 4
_ 105. 7
27. 5
28. 8
207
of this lowered carbon content can be best appreciated by
65. 8
95. 9
22. 0
23. 7
228
64.
1
114.
2
44.
0
35.
4
192
realizing that carbon is usually speci?ed as about ten per
cent of the manganese level which would therefore be
HARDENED BY 1,250° F., 2 l-lilQqlélgts, W.Q. (AFTER TOUGHEN
about 1.2-1.4% for a standard 13% manganese steel.
This combination, together with about 2% each of nickel
55
and molybdenum in a standard 13-14% manganese steel
348 5 _____________ __
84. 5
104. 9
15.0
(“standard 13%”) produces, after precipitation harden
342 5 _____________ __
73.8
111.9
27. 5
I
27. 2
241
28. 9
235
ing, a yield strength of 90—100,000 p.s.i. and an elonga
tion of 20—30%. This in comparison to the standard 60 ‘HARDENED BY 1,300“ F., 2 HI%UGI§S, W.Q. (AFTER TOUGHEN
toughened alloy represents a doubling of yield at a sacri
?ce at the outside of only about half the ductility, and
348 5 _____________ __
82. 2
106. 9
18. 0
26. 8
241
342 5 _____________ _.
74. 2
108. 7
24. 5
28. 9
‘228
the accomplishment of this is another object of the pres
ent invention.
3,075‘, 838 I
HARDENED BY 1,300° E, 6 H3353, W.Q. (AFTER TOUGHEN
Heat
No.
YS!
'I‘S2
5 21...
57.6
50.6
587.0
4111.6
4104.1
584.0
107.2
115.8
141.5
154.0
148.5
140.0
10 24-.-
60.0
in area in Tables IIv and III- which follow arev on the 15» 261'“
52.8
96.6
128.7
120.6
799.3
505.6
66.5
55.3
96.0
TS
75. 6
2.5
11.6
286
79. 4
75. 2
86. 0
126. 5
3. 5
33. 0
l2. 3
30. 5
179
262
HARDENED BY 1,300“ F., 12 HOURS, AIR COOL
218 5 ............. __
81. 6
128
18. 5
23. 4
277
1 P.s.i.><103 based on 0.2% set.
2 P.s.i.><103.
3 Percent in 2”.
‘ Percent.
6 Requirements of yield-and elongation met.
The ‘values‘for‘yield, tensile, elongation and’ reduction
samebases as noted above in thefootnotes of‘Table'I. >
In view of ‘our observation that high‘ carbon contents
126.0
(above about. 0.7%“)v have a drastic’ eifectj in lowering
4120.9
4102.0
ductility,. it was concluded that the best combination ‘of
enhanced yield and notv seriously ‘impaired. elongation
20-
would be found at even lower carbon“ levels,v provided»
carbon was-not-so :low as ‘to- require having resort to»
sources ofv expensive ‘manganese,- as distinguished from‘;
Elongi RA.‘ BHN
Thermal history, °F.,
hours cooling
30.0
59.0
14.0
10.0
13.5
20.5
20.8
44.0
17.0
15.2
16.0
20.2
99.5
19.0
23.4 I 228
As cast.
114.0
144.0
169.0
142.5
130.5
127.0
106.3
43.5
7.0
5.5
9.5
21.5
29.5
19.5
35.0
3.5
v0.6
14.8
27.5
28.8
19.9
207
321
351
230
.277
262
223
2000-2-WQ.
2000-2-WQ+1400-6-WQ.
2000~2—WQ+1300—6—WQ.
2000-2-WQ+1200-8-WQ.
2000~2-WQ,+1200_2—WQ.
2000-2—WQ+10S0-8-WQ,.
Ascast.
105.7
35.5
30.9
200
2000—2—WQ.
130.5
6.0
9.6
153.0
5.0
3.5 1 351
137.5 7:10.15 13.4
129.5
20.5 22.7
194.2 128.0 ‘29.0 32.1
See ‘moraines; Tablé‘Ii
180 AS5555.
174 2000-24VQ.
286 2000-2—»WQ+1400-6~WQ.
332 2000-.-WQ+1300-6_WQ.
321 2000—2—WQ+1300-2—WQ.
286 2000—2~WQ+1200-8—WQ‘
‘
311- 2000—2—WQ+1400—6-WQ.
302
293
2000—2—WQ+l300-6-WQ.
2000-2-WQ+1200—8~WQ.
2000-2-WQ+1200-2-WQ.
277 2000—2—WQ+10S0—8—WQ.
'
n win be seen‘ from‘ ‘the foregoing‘ that 'underith'e' pres‘;
ent" invention, we"v are ‘able "to‘ increase signi?cantly; by
ferromanganes'e, ‘and more expensive alloying in general. -
precipitation "hardening, ' the‘ yield strength in‘ ' a standard
Nickel; for instanceais expensive and desirably is held: to 25 13% manganese steel"withoutseriously‘‘impairing'Iducsl
a-‘rninimum for
reason. __The_iollowing heats,~there
tilityi" This is accomplished- bylholding-carbon-between
fore, represent'the preferred‘ and least expensive form' of
the lirr?'tsb? about- '0.4-0.7%,-~ preferably-lO.4-0.5 %1 for"
alloy practiceslunder‘the present invention,; and it should
the best balance of yield and elongation, and holding
be umentionedfthat- itrwa's these heats 46541555151115
vanadium tobetween about-034.9%.» It is'moreo'ver
above set forthrange for the preferred-alloy:
30 " important-‘to *observe'that precipitation ‘hardening can be "
accomplished ‘e?iciently and 3at low cost because in- sev
TABLE-‘1r’
Prc"cipz'tatz'on Hardenable Manganese‘
eral instances the'hardening is produced after only two»
to'fourxhours‘ of heat treatment;
_
“
The-alloy-is further characterized by nickel contents
' ‘
’ of about 2 to ‘6%.v Thurs, nickel can be as low as about‘
Chemical composition’ '
Heat No.
:
0,
'percent
Mn,
Si,
percont
2%: provided about 2% of‘ molybdenum is present; but"
3% nickel (heat?342; 518511005 heat‘37). produces ‘satisv
1 .
Or.
Ni,
factory'result‘s with molybdenum absent.‘ From this and
other data’we’have' concluded’ that the'pr'esent alloyshou'ld“
per-_ per- per
cent cent cent
____ -_
4. 041' ‘
2.08
3.93
4.08"
3.55
' contain‘at‘lea'stf3%"total of nickel ‘and molybdenum."
7 Hence, ‘while we"have‘_“illustrated and described pre'-"
ferred'iembodiments-‘ofthe‘present invention; it is to be
understood that these v‘are capable of variation and m0di-'
Heat 1014161
N
.7
28.1.
Tensile'2
106.2
4110.1
4107.5
132.0
105.5
‘ ‘
56.0
581.9
49.6
110.4
‘13.5
‘4855
21.5
98.2 "27.5
‘55.4
'
precise?‘detailsset"fortln‘but desire ‘to avail ourselves of.
hom's'cooling"
As'cast:
103:2
‘31.5
such? changes 5551514555035555.1511 ‘within the purview
of: thefollowing claims.‘
We-clair'n:
’
37.3
17.8 __174
‘293 _20007—2—WQ-l-7l400>—6-VVQ.
z2000+2-WQ.
_
332 2000—2—WQ+1800—6—W'Q,.
332 2000—2—WQ+1300—2—W_Q.; 50
'
262 .2000-2-WQ,+l200T8—WQ._
1. A111 austeniticmanganese steel alloy containing'about
13» to 14%~manganese- ecapable-of-being precipitation
27.8 - 286 i2000-2~WQ+1200—4—W.Q;-.-.
hardenedto produce a yield strength of 70,000-p.s.i.
31.6 "'QOT‘As‘cast."
(0.2% set)»and an elongation of-at least 10% ‘(in 2")
and containing carbon restricted’to the range of about
133.0
102.0 “13.5,
44:0 17.0
v34.4 .22_8'_2000—2-'WQ,;,
.286. 2.000_—.2—.WQ+1400;6-WQ.W
147.0
8.5 12.2 332 2000-2-WQ+1300—6—WQ.
112.1
145.0
, 0.5
599.0 1127.5
21.0
5104.8 151.0 ' 23.5
37.'.'-
'
"196
143.0
7.5 12.2
143.0
10.0 11.8
‘132.5 ‘17.5 23.3
‘108.3 1 133.0
29---
‘
' 54j7' " ' 96.13 ' 23.0 20.0
v482.2
24856
45 I ?cation; and=welthereforedo not-wish to be limited to the
Eloug? 12.4.4 BHN " Thermal history?F; ‘
13.4
302
29.3 -' 203
26.8
277
31.5
48.2
106.1
46.0
486.5
4101.0
491.4
138.0
144.0
119.6
14.0 15.2
11.0 14.5
18.5 23.2
375'
See footnotes, Table I.
0.4 to 0.7%,,van‘adium additions restricted to the range
of about 0.3 to 0.9%; ‘and . an" addition selected‘ from the
group‘consis'ting'of ‘(a)' about‘ 3 to 6%”‘nickel and (b)
at"least'2%“ea'ch'of nickel‘ and'molybdenum' upto a total'
nickel-molybdenum content of‘ about 6%, balance essen-'
2000-2~W.Q+1300-2~W.Q.J
2000-2-WQ+1200.-8~W,Q.
2000-2-WQ+1200-4-WQ.
196'" As'casti'
183.
2000-2-‘W
170
302
270
2000-2-WQ.+1400-6-WQ.
2000_—2—WQ.-i-.1300-6—WQ.._
2000-2-WQ+1200-8-WQ.
_ _ ‘
.
..
-
tially iron; -
2.'An'~=alloy'according-to‘claim' 1 wherein carbon is
restricted to the’narrow rangevof 0.4—0.'5%‘carbon, hav~
ing- a yield strength of-90-100,000 p.s.i. (0.2% set) and"
anr'elongation of at least about>20%' (in 2"), after‘ pre~'
7
TABLE III
Precipitation 1 Hardenable Mangimesé 'Stecls- -'
65
With 0.5 Carbon
" cipitation hardening;
References‘ Cited ‘int-he ?le of this-patent»
Chemical composition
UNITED STATES’ PATENTS ~
Hent~No.-
o,-
Mn,
81,
per;
cent
Cr,
per- ,per; 'percent cent cent
0.54
l 0.49
0.50
N1, M0,
v, v 17,, .41. I
per; 'DEFcent cent
per
cent
2.06. 2:04 0.55 0.045’ .062]:
"
2.08
.
2.07
0.83 Max:
.051‘
~2.D7~ 0.~81-~ ._¢=_—=-; .».===-.
2,365,740
Hege'r'et'al. __________ _- Dec. 23; 1958
OTHER REFERENCE-S
Bullens: Steel andltsI-Ieat Treatment, vol.‘ 2,1 4th ed,
page '406, published by John Wiley & Sons, »Inc.. New
York, N.Y.
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