TWO-PHASE STAINLESS STEEL

摘要

Provided is a two-phase stainless steel which has high strength, also has excellent SCC resistance and SSC resistance in a high-temperature chloride environment, and does not undergo the precipitation of a sigma phase. A two-phase stainless steel according to an embodiment of the present invention contains, in mass%, 0.03% or less of C, 0.2 to 1% of Si, more than 5.0% and 10% or less of Mn, 0.040% or less of P, 0.010% or less of S, 4.5 to 8% of Ni, 0.040% or less of sol. Al, more than 0.2% and 0.4% or less of N, 24 to 29% of Cr, 0.5% or more and less than 1.5% of Mo, 1.5 to 3.5% of Cu, 0.05 to 0.2% of W and a remainder made up by Fe and impurities, wherein a requirement represented by formula (1) is fulfilled. Cr+8Ni+Cu+Mo+W/2 >= 65 (1) To each element symbol in formula (1), a value of the content (mass%) of the corresponding element is assigned.