FERRITE AUSTENITE TWO-PHASE STAINLESS STEEL SHEET AND WELDMENT STRUCTURE, AND MANUFACTURING METHOD THEREFOR

摘要

To provide a two-phase stainless steel sheet excellent in corrosion resistance of a weldment part, and a weldment structure using the same.SOLUTION: There is provided a ferrite austenite two-phase stainless steel sheet having a chemical composition containing, by mass%, C≤0.050%, Si≤2.00%, Mn:0.50 to 6.00%, P≤0.050%, S≤0.050%, N:0.08 to 0.25%, Cr:17.0 to 30.0%, Ni:0.10 to 8.00%, Cu:0.10 to 1.50%, Nb:0 to 0.10%, Mo:0 to 3.50%, Sn:0 to 1.00%, W:0 to 1.00%, V:0 to 1.00%, Ti:0 to 0.05%, B:0 to 0.0050%, Ca:0 to 0.0050%, Mg:0 to 0.0050%, Al:0 to 0.05%, REM:0 to 0.50%, and the balance Fe with impurities, and having a PREN_Mn value of less than 40.0, a DF value of 40.0 to 65.0, corrosion potential reduction amount estimated value of the weldment part of less than 100 mV, and ferrite grain size of less than 12.0 μm.SELECTED DRAWING: Figure 2