This paper examines the impact of welding parameters on tensile shear fracture load, nugget geometry and microstructure of resistance spot welds (RSW) of austenitic stainless steel AISI 316 L and duplex stainless steel 2205 under lap shear loading condition. The macroscopic examination resulted that many of the nugget lengths were nearer to and higher than the AWS recommended value 4√t and failed at higher tensile shear load. Nugget height for DSS 2205 side was higher in comparison with AISI 316 L due to higher thermal conductivity of duplex stainless steel. Three welding parameters mainly welding current of 9 kA, heating cycle of 9 and electrode tip diameter of 6 mm were discovered as most effectual parameters on the tensile shear load and microstructure of weldments. Heterogeneous hardness was observed in the fusion zone due to the transition of equiaxed to columnar grains takes place in the both sides of nugget edge. DSS HAZ nearby BM observed higher hardness and ASS HAZ nearby BM reported lower hardness. WMZ Microstructure confirmed that thickness of austenite layers increased with heat input. Also, an unmixed zone in the microstructure identified as HAZ which contains delta ferrite. Scanning Electron Microscope (SEM) images in the nugget zone for different welding parameters confirmed that Intra-Granular Austenite (IGA) highly developed at higher welding current. SEM fractrograph for the tensile sheared specimens at higher and lower heat input confirmed the ductile type fracture even failed at Inter-Facial (IF) mode. Nugget area and nugget hardness were positively correlated with Tensile Shear Fracture Load (TSFL).

本文研究了搭接剪切载荷条件下焊接参数对奥氏体不锈钢AISI 316 L和双相不锈钢2205的拉伸剪切断裂载荷，熔核几何形状和电阻点焊（RSW）显微组织的影响。宏观检查结果表明，许多熔核长度都接近并高于AWS建议值4√t，并且在较高的拉伸剪切载荷下失效。DSS 2205侧面的熔核高度比AISI 316 L高，这是因为双相不锈钢的导热系数更高。发现了三个焊接参数，它们是对焊接件的拉伸剪切负荷和显微组织最有效的参数，主要为9 kA的焊接电流，9的加热周期和6 mm的电极头直径。在熔核区观察到异质硬度，这是由于等轴晶向柱状晶粒的转变发生在熔核边缘的两侧。BM附近的DSS HAZ观察到较高的硬度，而BM附近的ASS HAZ观察到较低的硬度。WMZ显微组织证实，奥氏体层的厚度随热输入而增加。同样，在微结构中的未混合区域被标识为HAZ，其中包含δ铁素体。在不同焊接参数的熔核区域中的扫描电子显微镜（SEM）图像证实，在较高的焊接电流下，晶粒内奥氏体（IGA）高度发达。在较高和较低热量输入下的拉伸剪切试样的SEM断口扫描仪证实，延展型断裂甚至在界面（IF）模式下失败。