Precipitation hardening stainless steel and its manufacture

Abstract

There is provided a precipitation hardening stainless steel with the composition: C: 0.05-0.30 wt %, Ni: 9-10 wt %, Mo: 0.5-1.5 wt %, Al: 1.75-3 wt %, Cr: 10.5-13 wt %, V: 0.25-1.5 wt %, Co: 0-0.03 wt %, Mn: 0-0.5 wt %, Si: 0-0.3 wt %, and remaining part up to 100 wt % is Fe and impurity elements, with the additional proviso that the amounts of Al and Ni also fulfil Al=Ni/4±0.5 in wt %. Further Cris in the interval 11-15.4 wt % and Niis in the interval 10.5-15 wt %. There is the possibility to have very low amounts of cobalt, well below 0.01 wt %. The precipitation hardening stainless steel displays, low segregation, high yield strength at elevated temperatures, and can also suitably be nitrided. The precipitation hardening stainless steel is more economical to manufacture compared to stainless steel according to the state of the art with the same strength at elevated temperatures.