双面超薄不锈钢复合板激光焊接接头组织及耐腐蚀性能

Study on Laser Welding Process and Microstructure of Double-sided Ultrathin Stainless Steel Clad Plate

采用同步送粉填充焊的方法,利用Nd:YAG固体脉冲激光对0.1mm+0.8mm+0.1mm不锈钢复合板进行了双面焊双面成形的实验研究。确定了激光焊接双面超薄不锈钢复合板的最佳工艺参数,利用金相显微镜观察分析了焊缝区各区的微观组织特征。结果表明,双面超薄不锈钢复合板填充粉末后激光焊接接头表面成形好,热影响区窄,焊接变形小;焊缝中心为细小的等轴晶,熔合线附近有细晶区,其他区域为柱状晶区,焊缝为残余奥氏体+马氏体+碳化物组织;在硫酸-硫酸铜腐蚀溶液中腐蚀16h后,焊缝表面与腐蚀前没有明显变化,对试板进行180°弯曲试验,未产生晶间腐蚀裂纹。

The experiment of 0.1mm＋0.8mm＋0.1mm Stainless steel clad plate double-sided filling high Cr-Ni powder welding was studied using Nd：YAG solid-state pulse laser. The optimum process parameters of laser welding were determined. Microstructure of the weht was studied by microscope. A good, narrow and little distortion welds were formed. The connection of weld metal with cladding stainless steel and base carbon steel are fine. The laser weld grains are smaller than the base metal, and heat affected zone is almost invisible. Weld center is equiaxial crystal, whereas other area is tiny columnar crystal, and grain orientation is not rule. After 16h, the weld surfaces had no change corresponding with the former sample in H2SO4-CuSO4 etehant solution. The experiments results of 180°bend specimens show there were no intergranular corrosion crack.