| 摘要 |
PROBLEM TO BE SOLVED: To provide, in a narrow groove tandem submerged arc welding method of improved 9Cr-1Mo steel, a welding method which is excellent in welding efficiency, satisfactory in a slag peeling efficiency and a bead state, and which can suppress the occurrence of a hot crack of molten metal.SOLUTION: A narrow groove tandem submerged arc welding method uses as a mother material an improved 9Cr-1Mo steel containing C, Si, Mn, P, S, Ni, Cr, Mo, V, Nb, Al, Ti, Zr and N in predetermined quantities, and the remainder being Fe and an inevitable impurity, and a welding wire containing C, Si, Mn, P, S, Ni, Cr, Mo, V, Nb, N and O at predetermined quantities, and the remainder being Fe and an inevitable impurity and having a wire diameter of 4.0 mm&phgr;, uses an AC power source indicating depending characteristics with the combination of said welding wire and a welding flux of a predetermined alkaline degree, and performs the welding under the predetermined conditions of a wire feeding speed Vof the preceding electrode, a wire feeding speed Vof the trailing electrode, a welding speed v, and the deposition quantity per unit length.SELECTED DRAWING: None |
