780DP钢与DC04普碳钢的窄搭接焊接

Narrow Overlap Welding of 780DP Steel and DC04 Plain Carbon Steel

在不同焊接工艺参数下对780DP钢和DC04普碳钢进行窄搭接焊接试验,研究了焊接工艺参数对两种钢焊接接头质量的影响。结果表明:焊接过程中热输入量过大和过小分别会造成焊瘤和未焊透两种典型焊接缺陷,其杯突试验裂缝均平行焊缝;焊接质量对电极轮压力的变化最为敏感,对焊接电流和焊接速度的敏感性依次减弱;由于受焊接热循环作用,焊接接头热影响区和焊缝区组织变化较大;焊缝区和热影响区的硬度相对于母材有所提高;当搭接量为1.7mm、传动侧焊接补偿为0.4mm、碾压轮压力为40kN时,焊接的最佳工艺参数为焊接电流16kA、焊接速度7m.min-1、电极轮压力15kN。

780DP steel and DC04 plain carbon steel were joined by narrow overlap welding with different welding parameters. The effects of welding parameters on welding quality of 780DP steel and DC04 plain carbon steel were studied. The results show that excessive and insufficient heat inputs may result in welding beading and lack of penetration, respectively, which are two typical welding defects. Furthermore, cracks of cupping test were both parallel to the welding seam. The welding quality was the most sensitive to the change of pressure of electrode wheel and weakened sensitive to the welding current and the welding rate in turn. Due to the function of the welding thermal cycle, the microstructure of heat affected zone and weld seam zone had large changes. The hardness of weld seam zone and heat affected zone increased relative to the base metal. When the amount of overlap was 1.7 ram, the welding compensation on the transmission side was 0.4 mm and the rolIing force was 40 kN, the optimal welding parameters were as follows： welding current of 18 kA, welding speed of 7 m min J and electrode pressure of 15 kN.