高强度热成形钢点焊性能与接头组织

摘要

以热成形高强度钢板22MnB5作为研究对象,采用不同工艺参数对典型厚度钢板进行正交试验优化,通过对点焊试样进行单向拉伸试验,确定了最优点焊性能工艺参数及各因素对点焊性能的影响程度.热成形高强度钢点焊接头抗剪载荷的最优条件为:板料厚1.6mm、焊接电流7 800A、焊接时间0.4 s；同时,各因素对抗剪载荷影响的主次顺序为:板料厚度＞焊接电流＞焊接时间.通过对点焊接头进行硬度分布试验和金相组织测试,研究并分析了热成形高强度钢点焊接头的硬度分布情况和金相组织特性；采用扫描电镜探究了热成形高强度钢的点焊接头断口形貌特征.%The paper took the hot forming high strength steel 22MnB5 as research subjects, making use of different parameters to carry out the orthogonal optimization, to ascertain the optimum parameters on the welding performance and the factors' effort on the spot welding performance by the tensile test of the spot welding, The results showed that, the optima] conditions on the spot welding joint of the hot forming high strength steel was: specimen thickness 1.6mm ,spot welding current 7800A , spot welding time 0.4s; meanwhile, the order of affecting the spot welding performance was: specimen thickness>spot welding current>spot welding time. The hardness distribution and metallographic experiments were done, in order to investigate the hardness distribution and metallographie structure of the spot welding on the hot forming high strength steel. In addition, the paper explored the fracture morphology by the use of the scanning electron microscope.