Ultra-High Strength Martensitic Alloy
Abstract
An age hardenable martensitic steel alloy is disclosed. The alloy has the following composition in weight percent. C 0.30-0.36 Mn 0.05 max. Si 0.05 max. P 0.01 max. S 0.0010 max. Cr 1.30-3.2 Ni 10.0-13.0 Mo 1.0-2.70 Co 13.8-17.4 Ti 0.02 max. Al 0.005 max. Ce 0.030 max. La 0.010 max. The balance is iron and the usual impurities. The composition of this alloy is balanced to provide a unique combination of very high strength, together with good toughness, ductility, and resistance to fatigue.
Claims
exact text as granted — not AI-modified1 . An age hardenable martensitic steel alloy, consisting essentially of, in weight percent, about
C
0.32-0.36
Mn
0.05
max.
Si
0.05
max.
P
0.005
max.
S
0.0010
max.
Cr
1.30-2.30
Ni
11.5-13.0
Mo
1.8-2.70
Co
15.4-17.4
Ti
0.02
max.
Al
0.005
max.
Ce
0.030
max.
La
0.010
max.
the balance being iron and usual impurities.
2 . (canceled)
3 . An age hardenable martensitic steel alloy as set forth in claim 1 that contains at least about 2.0 weight percent chromium.
4 . (canceled)
5 . An age hardenable martensitic steel alloy as set forth in claim 1 that contains not more than about 16.0 weight percent cobalt.
6 . (canceled)
7 . (canceled)
8 . An age hardenable martensitic steel alloy as set forth in claim 1 that contains not more than about 2.2 weight percent molybdenum.
9 . (canceled)
10 . An age hardenable martensitic steel alloy, consisting essentially of, in weight percent, about
C
0.32-0.35
Mn
0.05
max.
Si
0.05
max.
P
0.005
max.
S
0.0010
max.
Cr
2.0-2.3
Ni
11.5-13.0
Mo
1.8-2.2
Co
15.0-16.0
Ti
0.015
max.
Al
0.003
max.
Ce
0.020
max.
La
0.010
max.
the balance being iron and usual impurities.
11 . (canceled)
12 . An age hardenable martensitic steel alloy as set forth in claim 10 that contains at least about 2.20 weight percent chromium.
13 . (canceled)
14 . (canceled)
15 . (canceled)
16 . (canceled)
17 . An age hardenable martensitic steel alloy as set forth in claim 10 that contains not more than about 2.0 weight percent molybdenum.
18 . An age hardenable martensitic steel alloy as set forth in claim 10 that contains not more than about 0.34 weight percent carbon.
19 . An age hardenable martensitic steel alloy, consisting essentially of, in weight percent, about
C
0.32-0.34
Mn
0.04
max.
Si
0.03
max.
P
0.003
max.
S
0.0005
max.
Cr
2.20-2.30
Ni
11.5-12.5
Mo
1.80-1.90
Co
15.4-16.0
Ti
0.01
max.
Al
0.001
max.
Ce
0.010
max.
La
0.005
max.
the balance being iron and usual impurities.
20 . An age hardenable martensitic steel alloy as set forth in claim 1 , 10 , or 19 comprising an element selected from the group consisting of calcium, magnesium, yttrium, and combinations thereof, in place of at least a portion of the cerium and lanthanum.
21 . An article of manufacture formed from a martensitic steel alloy having a weight percent composition consisting essentially of about
C
0.32-0.36
Mn
0.05
max.
Si
0.05
max.
P
0.005
max.
S
0.0010
max.
Cr
1.30-2.30
Ni
11.5-13.0
Mo
1.8-2.70
Co
15.4-17.4
Ti
0.02
max.
Al
0.005
max.
Ce
0.030
max.
La
0.010
max.
and the balance of said alloy is iron and usual impurities, wherein said article provides a tensile strength of at least about 345 ksi (2344 MPa).
22 . An article of manufacture as claimed in claim 21 wherein said article is in the age hardened condition.
23 . An article of manufacture as claimed in claim 21 which contains more than 1.8% molybdenum.
24 . An article of manufacture as claimed in claim 21 wherein the ratio Ce/S is greater than 4.
25 . An article of manufacture as claimed in claim 24 wherein the ratio Ce/S is not greater about 20.Join the waitlist — get patent alerts
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