Patent ID: 8603263

Claim:
A duplex stainless steel for use in applications requiring alkali resistance having a chemical composition comprising, in mass %, C: at most 0.03%, Si: at most 0.5%, Mn: at most 2.0%, P: at most 0.04%, S: at most 0.003%, Cr: at least 25.0% to less than 28.0%, Ni: at least 6.0% to at most 10.0%, Mo: at least 0.2% to at most 3.5%, N: less than 0.5%, W: at most 3.0%, and a remainder of Fe and impurities, wherein the duplex stainless steel is rolled and it has an average transverse grain diameter of austenite grains in a rolling stretcher section of at most 350 μm.