Pitting resistant duplex stainless steel alloy with improved machinability and method of making thereof

摘要

A highly pitting resistant duplex stainless steel alloy is provided which compromises in weight percentages: C: 0.10% and below; Si: 1.5% and below; Mn: 2.0% and below; Cr: 25.0% to 27.0%; Ni: 5.0% to 7.5%; Cu: 1.5% to 3.5%; N: 0.15% and below; Mo: 0.5% and below; and the remaining portion being substantially iron and unavoidable impurities. This alloy has greatly improved machinability when treated in the mold after casting by an accelerated heat treatment, as compared to the same alloy composition that is very slowly control cooled in a tightly closed heat treatment furnace.