Patent ID: 7901519

Claim:
A precipitation-hardenable martensitic stainless steel comprising, in percent by weight: 11.0% to 12.5% chromium; 1.0% to 2.5% molybdenum; 0.15% to 0.5% titanium; 0.7% to 1.5% aluminum; 0.5% to 2.5% copper; 9.0% to 11.0% nickel; up to 0.02% carbon; 0. 5% to 1.5% tungsten; and up to 0.001% boron; wherein iron and incidental impurities are substantially the remainder of the total content, and wherein the stainless steel has a yield strength of at least 230 ksi, K IC of at least 70 ksi·in 1/2 , and K ISCC of at least 50 ksi·in 1/2 .