Precipitation hardening steel

Claim 2

A precipitation hardened composition, consisting essentially of about 0.10 to 0.20 percent carbon, 0.60 percent maximum silicon, 0.75 percent maximum manganese, 1.25 to 3.00 percent chromium, 1.25 to 3.00 percent nickel, 1.50 to 3.00 percent molybdenum, and 1.50 to 3.00 percent copper, with the remainder essentially iron; said composition being characterized by an essentially uniform precipitation hardened structure in which precipitation of the age hardenable phase at the grain boundaries is substantially avoided.

Claim 3

A precipitation hardenable composition consisting essentially of about 0.10 to 0.20 percent carbon, 0.60 percent maximum silicon, 0.75 percent maximum manganese, 1.25 to 3.00 percent chromium, 1.25 to 3.00 percent nickel, 1.50 to 3.00 percent molybdenum, 1.50 to 3.00 percent copper, and about 0.05 percent nitrogen with the balance being substantially iron.

Claim 4

A low carbon alloy composition, precipitation hardenable to a hardness in excess of Rockwell C 50 on aging at about 1,050* F, said alloy composition consisting essentially of about 0.10 to 0.25 percent carbon, 1.00 percent maximum silicon, 1.00 percent maximum manganese, 0.75 to 5.00 percent chromium, 1.00 to 4.00 percent nickel, 1.00 to 4.00 percent molybdenum, and 1.25 to 3.50 percent copper, the balance iron with incidental impurities; said alloy composition being characterized by a total austenite alloying effect of from about 8 to 16 and a total ferrite alloying effect of from about 7 to 14.