| abstract |
a duplex stainless steel with suppressed honeycomb corrosion is provided. a duplex stainless steel steel according to the present disclosure contains a chemical composition consisting of, in% by mass, cr: more than 27.00% to 29.00%, mo: 2.50 to 3.50%, ni: 5.00 to 8.00%, w: 4.00 to 6.00%, cu: 0.01 less than 0.10%, n: more than 0.400% to 0.600%, c: 0.030% or less, if: 1.00% or less, mn: 1.00% or less, sol.al: 0.040% or less, v: 0.50% or less, o: 0.010% or less, p: 0.030% or less es: 0.020% or less with the balance being fe and impurities and satisfying formula (1), a microstructure consisting of 35 to 65% by volume of ferrite phase with the balance being the austenite phase, and the fraction of area of cu precipitated in the ferrite phase is 0.5% or less. cr + 4.0xmo + 2.0xw + 20xn-5xln (cu) = or> 65.2 (1) |