Welding wire for modified 9Cr-1Mo steel, and submerged-arc welding material

摘要

A welding wire for a modified 9Cr-1Mo steel is provided which comprises C: 0.070 to 0.150% by mass, Si: more than 0.15% by mass, but not more than 0.30% by mass, Mn: not less than 0.30% by mass, but less than 0.85% by mass, Ni: 0.30 to 1.20% by mass, Cr: 8.00 to 13.00% by mass, Mo: 0.30 to 1.40% by mass, V: 0.03 to 0.40% by mass, Nb: 0.01 to 0.15% by mass, N: 0.016 to 0.055% by mass, P: not more than 0.010% by mass, S: not more than 0.010% by mass, Cu: less than 0.50% by mass, Ti: not more than 0.010% by mass, Al: less than 0.10% by mass, B: less than 0.0010% by mass, W: less than 0.10% by mass, Co: less than 1.00% by mass, and O: not more than 0.03% by mass, wherein the total amount of Mn and Ni being not more than 1.50%. The welding wire provides good toughness without degradation of creep rupture strength even at the PWHT temperature of 760° C. or above.