430不锈钢微束等离子弧焊接头的组织及耐腐蚀性能研究

Microstructure and Corrosion Resistance of Micro-Plasma Arc Welded Joint of 430 Stainless Steel

采用微束等离子弧焊对1.2 mm厚的430不锈钢薄板进行对焊试验,通过分别改变焊接电流、焊接速度和离子气流量的单变量试验得到了优化的焊接工艺参数,研究了最优参数下接头的显微组织和耐腐蚀性能。结果表明：焊接电流为22 A,焊接速度为115 mm/min,离子气流量为0.6 L/min时,焊缝的成形效果最好。焊缝组织中马氏体被拉长,铁素体晶粒变得粗大,沿晶界方向还有碳化物条带。接头的耐腐蚀性能比母材的差。

The butt welding tests of 430 stainless steel sheet with the thickness of 1.2 mm were carried out by using micro-plasma arc welding process, and the welding parameters were optimized by single variable tests for adjusting the welding current, welding speed and ionic gas flow rate respectively, and the microstructure and corrosion resistance of the joint under the optimal parameters were studied. The results show that when the welding current is 22 A, the welding speed is115 mm/min, and the ionic gas flow rate is 0.6 L/min, the weld forming is the best. In the weld microstructure, the martensite is elongated, and the ferrite grains coarsen, and there is carbide band along the grain boundary. The corrosion resistance of the joint is worse than that of the base metal.