Hy-130/150 Weldments: Development of Filler Metals and Joining Procedures

摘要

Metal-inert-gas (MIG) and covered-electrode filler metals and procedures for their use received the greatest attention in this study. Studies showed that a filler wire composition of 0.10 C, 1.8 Mn, 0.3 Si, 2.0 Ni, 0.9 Cr, 0.5 Mo, and 0.01 Ti produced MIG welds having optimum properties. A production air-melted wire of this nominal composition was used to make MIG-spray and dip-transfer weldments whose yield strengths exceeded 135 k.s.i. and CVN toughness exceeded 50 ft-lb. at +30 F and 20 ft-lb. at -60 F. These properties are superior to those specified as minima. Although the yield strength is affected by the amount of preheat and arc energy input, it exceeded 135 k.s.i. if they were held within the ranges normally used for fabricating HY-80 plate. A broad range of covered-electrode compositions was studied and the optimum was found to be essentially the same as that recommended for MIG welds. Improvements in the core wire and coating formulations resulted in welds having sufficient strength and toughness. For covered-electrode weld metals deposited in both flat and vertical positions, the yield strength exceeded 135 k.s.i., and the CVN toughness exceeded 50 ft-lb. at +30 F and 20 ft-lb. at-60 F.