AN ENHANCED MACHINABILITY PRECIPITATION-HARDENABLE STAINLESS STEEL FOR CRITICAL APPLICATIONS.

摘要

A precipitation-hardenable, martensitic stainless steel alloy is described having the following composition in weight percent: C 0.030 max.; Mn 1.00 max.; Si 1.00 max.; P 0.030 max.; S 0.005-0. 015; Cr 14.00-15.50; Ni 3.50-5.50; Mo 1.00 max.; Cu 2.50-4.50; Nb+Ta (5xC)-0.30; Al 0.05 max.; B 0. 010 max,; N 0.030 max; and the balance is essentially iron and the usual impurities. The alloy provides a unique combination of properties in that useful articles made therefrom provide superior machining characteristics relative to known high strength 15Cr-5Ni precipitation-hardenable stainless steel alloys, while meeting the strength, ductility, and hardness requirements specified in AMS 5659 for critical applications.