材料期刊网

通过电阻点焊对1.5 mm厚GH163镍基高温合金进行焊接,研究了焊接电流、电极压力、焊接时间对接头显微组织、显微硬度和拉剪力的影响,得到了较佳的焊接参数.结果表明:接头熔核区均匀分布着细小的枝状柱状晶,其生长方向垂直于熔核弧线,与熔核的散热方向一致,晶粒随着电流的增大而变细;接头显微硬度随着距熔核中心距离的减小而增大,随着焊接电流的增大整体呈现增大趋势;接头的拉剪力随焊接电流的增大呈先增大后减小再增大的变化趋势,随着焊接时间的延长而逐渐增大,随着电极压力的增大而下降;当电极压力为11.0 kN、焊接电流为7.1 kA、焊接时间为0.50 s时,接头的综合性能最佳,熔核直径达到7.14 mm,室温和高温拉剪力分别为15.34,13.13 kN,拉伸断裂方式为母材撕裂.

The resistance spot welding was conducted on 1.5 mm thick GH163 nickel-based superalloy, and the effects of welding current, electrode pressure and welding time on the microstructure, microhardness and tensile shear of the joint were studied.The relatively good welding parameters were obtained.The results show that the fine dendritic columnar crystals was uniformly distributed in the nugget zone of the joint, with the growth direction perpendicular to the nugget arc line, which was the same direction as the heat radiating of the nugget.Meanwhile with the current increase, the grain size decreased.The microhardness of the joint increased with the shortening distance to the nugget center while showed an increasing trend with the increasing welding current.The tensile shear of the joint first increased then decreased, and then increased again with the welding current increase, and gradually increased with the prolongation of welding time while decreased with the increase of electrode pressure.When the electrode pressure was 11.0 kN, welding current was 7.1 kA and welding time was 0.50 s, the comprehensive properties of the joint were the best, with the nugget diameter of 7.14 mm, the room and high temperature tensile shear force of 15.34 kN and 13.13 kN, and the tensile fracture mode of base metal fracture.