| 摘要 |
PROBLEM TO BE SOLVED: To provide a two-phase stainless steel for urea-producing plants having excellent corrosion resistance. SOLUTION: The stainless steel comprises, by mass,≤0.03% C,≤0.5% Si,≤2% Mn,≤0.04% P,≤0.003% S,≥26% but <28% Cr, 6-10% Ni, 0.2-1.7% Mo, >2% but≤3% W, >0.3% but≤0.4% N,≤0.3% Cu as an impurity and the balance being Fe and impurities. The steel may further comprise at least one chosen from Ca, Ce and B and preferably comprises≤0.05% Al and≤0.01% O within the impurities. Preferably, the difference between hardness of the stainless steel at a solution state and hardness achieved after the stainless steel is subjected to a heat treatment wherein it is heated at 800°C for 30 min and subsequently water cooled, is≤80 in terms of Vickers hardness. COPYRIGHT: (C)2004,JPO
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