Claims
- 1. A case-hardening alloy steel which when case hardened and heat treated has, at room temperature, a core which has a hardness of at least Rc 32, a Charpy V-notch impact strength of at least 60 ft-lb, a fracture toughness of at least 80 ksi .sqroot.in combined with a case which has at room temperature a hardness of at least Rc 60 and a hot hardness at 400.degree. F. of at least Rc 56, said alloy steel consisting essentially in weight percent of
- ______________________________________ w/o______________________________________ C 0.06-0.16 Mn 0.2-0.7 Si 0.5-1.5 Cr 0.5-1.5 Ni 1.5-3 Cu 1-4 Mo 2.5-4 V Up to 0.4 P Up to 0.05 S Up to 0.05 N Up to 0.03 Al Up to 0.25 Cb Up to 0.25 Ti Up to 0.25 Zr Up to 0.25 Ca Up to 0.25______________________________________
- the sum of the percent nickel plus one-half the percent copper being equal to or less than 4%, and the balance consisting essentially of iron.
- 2. The alloy steel as set forth in claim 1 which contains at least 0.03% V and no more than 0.1% of each Al, Cb, Ti, Zr and Ca.
- 3. The alloy steel as set forth in claim 2 which contains about
- ______________________________________ C 0.07-0.13 Mn 0.25-0.5 Si 0.75-1.25 Cr 0.75-1.25 Ni 1.7-2.3 Cu 1.5-2.5 Mo 3-3.5 V 0.05-0.15______________________________________
- 4. The alloy as set forth in claim 2, which contains no more than 0.13% carbon, no more than 0.5% manganese, no more than 1.25% silicon, no more than 1.25% chromium, no more than 2.3% nickel, no more than 2.5% copper, no more than 3.5% molybdenum, and no more than 0.15% vanadium.
- 5. The alloy steel as set forth in claim 4 which contains at least 3% molybdenum.
- 6. The alloy steel as set forth in claim 2 which contains
- ______________________________________ w/o______________________________________ C 0.1 Mn 0.35 Si 1 Cr 1 Ni 2 Cu 2 Mo 3.25 V 0.1______________________________________
- 7. The alloy steel as set forth in claim 2 which is case hardenable and heat treatable to a room temperature hardness of Rc 62 and which contains at least about 0.75% Si, 0.75% Cr, 1.7% Ni, 1.5% Cu, and 3% Mo.
- 8. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 1.
- 9. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 2.
- 10. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 3.
- 11. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 4.
- 12. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 5.
- 13. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 6.
- 14. A wrought, case-hardened and heat-treated article formed from the alloy steel of claim 7.
CROSS REFERENCES
This application is a continuation-in-part of our copending application Ser. No. 815,231, filed July 13, 1977, assigned to the assignee of this application, now abandoned.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3036912 |
Roberts et al. |
May 1962 |
|
3661565 |
Harvey |
May 1972 |
|
3713905 |
Philip et al. |
Jan 1973 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
815231 |
Jul 1977 |
|