COATED ELECTRODE FOR 9Cr-1Mo STEEL WELDING

摘要

To provide a coated electrode for 9Cr-1Mo steel welding favorable in welding workability and capable of obtaining a favorable strength or the like even if a PWHT (post weld heat treatment) temperature is 750°C or higher.SOLUTION: An objective coated electrode includes in one or both of a core wire and coating material in a core wire mass ratio, 0.05-0.15% of C, 0.1-1.0 of Si, 0.7-1.5% of Mn, 0.1-0.6% of Ni, 9-11% of Cr, 0.5-1.5% of Mo, 0.02-0.20% of Nb, 0.01-0.15% of Cu, 0.1-0.8% of Al, 0.1-0.4% of V, 0.3-1.5% of Mg and 0.02-0.10% of N. The coating material includes in mass%, 3-10% of SiOconversion value, 3-8% of ZrOconversion value, 0.01-0.50% of AlOconversion value, 15-40% of total Ca conversion value, 6-17% of total F conversion value, 0.1-1.0% of MgO and 1-3% of total of Na and K conversion values and besides, total Ca conversion value/total F conversion value is 2.0 to 3.0.SELECTED DRAWING: None