轨道交通装备不锈钢激光焊工艺研究及其应用

Research and application of laser welding techniques for stainless steel on rail transit equipment

为提升轨道交通电气屏柜外观质量,通过金相及扫描电镜组织观察、室温拉伸力学及疲劳性能检测等手段对不同激光焊参数下的304不锈钢激光焊接接头进行了研究。结果表明:当焊接功率P=1390W、焊接速率ν=13 mm/s、离焦量f=-10 mm时,焊接接头熔深和宽度分别为2.21 mm、2.91 mm,其抗拉强度、屈服强度、伸长率、疲劳极限分别为785.9 MPa、241.7 MPa、75.6%、265 MPa。室温拉伸断裂后,焊接接头呈现韧窝断裂特征。因激光焊接具有高效和明显的外观提升效果,已推广至机车、动车和城轨装备制造中。

To promote the appearance quality of the electric cabinets on rail transit equipment,a study on the welded joint of SUS304 stainless steel under different laser welding parameters is carried out by means of microstructure observation through metallurgical and scanning electron microscope,tensile mechanical test at room temperature and fatigue performance test.Test results indicate that when the welding power P=1390 W,welding rate v=13 mm/s and the defocusing amount f=-10 mm is maintained,a welded joint penetration of 2.21mm and a joint width of 2.91mm could be achieved,and its tensile strength,yield strength,elongation,fatigue limitcan reach 785.9 MPa,241.7 MPa,75.6%and 265 MPa respectively.When the room-temperature tensile failure happens,the welded joint exhibits the feature of dimple fracture.Laser welding has been promoted to the manufacture of locomotives,EMUs and urban transit vehicles due to its high efficiency and effect of obvious appearance improvement.