| 摘要 |
PROBLEM TO BE SOLVED: To provide a Sn-containing ferritic stainless steel excellent in heat resistance.SOLUTION: A ferritic stainless steel includes, by mass%, ≤0.015% C, 0.05-1.5% Si, ≤1.5% Mn, ≤0.035% P, ≤0.015% S, 13-21% Cr, 0.05-0.50% Sn, 0.20-0.60% Nb, ≤0.05% Ti, and ≤0.002% N, with the balance of Fe and inevitable impurities, while satisfying formula (1): 8≤CI=(Ti+0.52Nb)/(C+N)≤26, and formula (2): GBSV=Sn+1.3Ti-Nb-0.3Mo-0.06≤0. When heat treatment is applied at 600 to 750°C so that an L value of formula (3): L=(273+T)(log(t)+20) becomes ≥1.91×10, a Sn concentration at the grain boundary is ≤2 atom%, where T represents a temperature (°C) and t represents a time (h). |
