316L不锈钢超薄板激光焊接头微观组织及力学性能研究

Study on Microstructure and Mechanical Properties of 316L Stainless Steel Ultra-thin Sheet Laser Welded Joint

为了探索316L不锈钢超薄板在换热器、金属极板等领域的应用,采用脉冲激光器对0.15 mm厚316L不锈钢板进行激光焊接工艺实验,并对焊接接头的微观组织和力学性能进行了分析。结果表明:当激光功率为90W、焊接速度为25 mm/s、脉冲频率为90 Hz、激光焦距为-1.5 mm时,能够得到单面焊双面成型、表面光滑无缺陷的焊接接头。焊缝区由细小的等轴晶组成,硬度高于母材区的,焊接接头的抗拉强度约为539.5 MPa,达到母材的86.8%,断后伸长率约为30.5%,达到母材的75.7%。

In order to explore the application of 316L stainless steel ultra-thin sheet in heat exchanger,metal pole sheet and other fields,a pulsed laser was used to perform laser welding process experiments for 0.15mm thick 316L stainless steel sheets,and the microstructure and mechanical properties of the welded joints were analyzed.The results show that when the laser power is 90 W,the welding speed is 25 mm/s,the pulse frequency is 90 Hz,and the laser focal length is-1.5 mm,a welded joint with single-side welding and double-side forming,smooth and defect-free surface can be obtained.The weld zone is composed of fine equiaxed crystals and the hardness is higher than that of the base metal zone.The tensile strength of the welded joint is about 539.5 MPa,reaching 86.8%of the base metal,and the elongation after fracture is about 30.5%,reaching 75.7%of the base metal.