不锈钢薄板激光点焊工艺对金相组织的影响分析

以厚度为0.5 mm的304不锈钢薄板作为研究对象,通过实验探讨了不同工艺下激光点焊的金相组织、力学性能.经过焊点金相微观组织的观察和焊点拉伸强度的试验,可得出结论:激光点焊焊接质量良好,很少出现气孔、飞溅、焊接裂纹、未熔透、未熔合等焊接缺陷,而且不同的激光功率密度或加热时间,对焊点的形貌、尺寸和金相组织有很大影响; 焊点处的耐腐蚀性强度比母材低,而且大部分焊点拉伸位移达到1.5 mm左右就会断裂,平均拉伸强度比母材低281.2 MPa,但平均屈服强度比母材高,满足不锈钢薄板作为换热器的需求.

The Effects of Stainless Steel Laser Spot Welding on Metallographic Analysis

The microstructure and mechanical properties of laser spot welding of 304 stainless steel sheet with thickness of 0.5 mm are investigated by experiments.After the test of solder joint microstructure observation and tensile strength of the solder joints,the conclusion is drawn that the laser spot welding quality is good,lessporosity,spatter,weldingcracks,incompletepenetration,incomplete fusion welding defects,and different laser power density or heating time has a great influence on the morphology,size and solder joint microstructure,corrosion resistance of the solder joint strength is lower than the parent metal,and most of the solder joints tensile displacement reaches about 1.5 mm will break,the average tensile strength is 281.2 MPa lower than the parent material,but the average yield strength is higher than that of base metal,stainless steel sheet is used as a heat exchanger to meet the material requirement.