焊接电流对不锈钢薄板焊接接头组织性能的影响

Influence of Welding Current on Structure Properties of Stainless Steel Sheet Weld Joint

文中主要研究焊接电流分别为15、22、25 A的条件下,不锈钢薄板焊接接头的力学性能和显微组织的变化。通过全谱直读式光谱仪进行化学成分分析,通过电子万能试验机和维氏硬度计进行焊接接头的力学性能测试,通过体视显微镜和金相显微镜进行焊接接头的宏观组织和微观组织分析。随着焊接电流的增大:焊缝部分的显微组织由心部等轴晶粒到均匀的铁素体组织,再到晶粒长大,变成各向异性的非等轴晶;焊缝的抗拉强度和硬度均为先增后减,断后伸长率呈逐渐下降的趋势。当焊接电流为22 A时,焊接接头呈现较好的综合性能。

The present study conducted the changes of mechanical properties and microstructure of stainless steel sheet weld joint with welding current of 15 A,22 A and 25 A.The chemical composition was determined by full spectrum direct reading spectrometer,mechanical properties were conducted by electronic universal testing machine and Vickers hardness tester,the macroscopic structure and microstructure of the weld joint were analyzed by stereo microscope and metallographic microscope.With the increasing of welding current,the microstructure of the welding seam grows from equiaxed grains to uniform ferrite grains,and then to non⁃equiaxed grains with anisotropy.Tensile strength and hardness values of weld joint both increase first and then decrease,while the elongations get decreasing gradually.When the welding current is 22 A,the weld joints show better comprehensive performances.