| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for providing satisfactory mechanical properties such as strength and toughness of a welded joint of Cr-containing steel in which the content of C harmfully acting on corrosion resistance and weldability is extremely reduced. SOLUTION: The steel sheet for a welded structure having excellent corrosion resistance and mechanical properties in a natural gas-fired boiler exhaust gas environment has a composition containing, by mass,≤0.010% C, 0.05 to 2.0% Si, 0.05 to 0.50% Mn,≤0.050% P,≤0.0100% S, 6.0 to 9.0% Cr,≤0.100% Al, Ti:3×(C+N) to 0.50% and≤0.020% N, and, if required, further one or more metals selected from Cu, Ni, Mo, Nb and V, and the balance Fe with inevitable impurities, has a metallic structure comprising polygonal ferrite, and has Vickers hardness of 110 to 180. The welded joint is obtained by using the steel sheet. COPYRIGHT: (C)2005,JPO&NCIPI |
