摘要
对1.5 mm厚CP780镀锌复相钢板进行电阻点焊,研究了其焊接电流窗口、显微组织和力学性能,评估了点焊过程中电极的使用寿命。结果表明:试验钢板电阻点焊的焊接电流窗口为6.0~8.0 kA,最大和最小焊接电流下焊缝组织均主要为板条状马氏体,热影响区组织则主要由马氏体和部分铁素体组成;最大和最小焊接电流下熔核区硬度高于热影响区,且热影响区均存在软化区;最大焊接电流点焊接头的最大剪切力和最大正拉力分别为21.80,10.56 kN,比最小焊接电流下分别提高了51.8%,38.0%;在最大焊接电流下连续焊接2 000点后,熔核直径仍均大于临界熔核直径,电极使用寿命超过2 000点。
Resistance spot welding was conducted on CP780 galvanized complex-phase steel plate with 1.5 mm thickness. The welding current window, microstructure and mechanical properties of the steel plate were studied. The electrode life during the resistance spot welding was evaluated. The results show that the welding current window for the resistance spot welding of the test steel plate expanded from 6.0-8.0 kA. The microstructure of the weld under the maximum and minimum welding currents mainly consisted of lath martensite, and that of the heat affected zone consisted of martensite and some ferrite. The hardness of the nugget under the maximum and minimum welding currents was higher than that of the heat affected zone, and softening zones were found in the heat affected zone. The maximum shear force and positive tensile force of the spot weld joint at the maximum welding current were 21.80 kN and 10.56 kN, which were 51.8% and 38.0% higher than those at the minimum welding current, respectively. After continuous welding 2 000 points at the maximum welding current, the nugget diameter was still larger than the critical nugget diameter, indicating the electrode life exceeded 2 000 points.
作者
王鹏博
张永强
付参
鞠建斌
伊日贵
WANG Pengbo;ZHANG Yongqiang;FU Can;JU Jianbin;YI Rigui(Research Institute of Technology of Shougang Group,Beijing 100043,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2021年第5期63-66,83,共5页
Materials For Mechanical Engineering
关键词
复相钢
电阻点焊
电流窗口
力学性能
complex-phase steel
resistance spot welding
current window
mechanical property
