ULTRA-HIGH-STRENGTH PRECIPITATION-HARDENABLE STAINLESS STEEL AND ELONGATED STRIP MADE THEREFROM

摘要

A precipitation hardeanble stainless steel having the following weight percent composition is disclosed. C 0.030 max. Mn 0.5 max. Si 0.5 max. P 0.040 max. S 0.025 max. Cr 9-13 Ni 7-9 Mo 3-6 Cu 0.75 max. Co 5-11 Ti 1.0 max. Al 1.0-1.5 Nb 1.0 max. B 0.010 max. N 0.030 max. O 0.020 max. The balance of the alloy is essentially iron and the usual impurities. One or more rare earth metals or calcium may be included in the alloy for removing and/or stabilizing phosphorus and sulfur. The alloy provides a unique combination of strength, toughness, and ductility. There is described a useful article such as an aircraft structural component or a golf club head that is formed, at least in part, from the aforesaid alloy. In accordance with a further aspect of the invention, there is an elongated strip formed from the aforesaid stainless steel.