激光焊接工艺对TRIP590钢焊接接头组织性能的影响

Effect of laser welding processes on microstructure and mechanical properties of TRIP590 steel welded joints

采用三因素、三水平正交实验方法设计激光焊接试验参数,研究了离焦量、焊接功率和焊接速度对TRIP590钢接头组织性能的影响,以断后伸长率为标准,获得了最佳工艺参数为功率2500 W,焊接速度67.7 mm/s,离焦量1 mm。结果表明,当离焦量为负值和零时接头焊缝区域硬度比离焦量为正值时高,此时马氏体的转变较充分,且热影响区马氏体和贝氏体组织较多,但焊接功率较大且焊接速度较低时接头焊缝的宽度无增大趋势,而在较低的焊接功率下,选择合适的离焦量会增大焊接热输入,进而促使焊缝硬度增加,马氏体的转变更加充分。

The microstructure and mechanical properties of TRIP590 steel laser welded joints were investigated by an orthogonal experiment design of three factors and three levels.Based on the criterion of break elongation,the optimized parameters are the welding power of 2500W,welding speed of 67.7 mm /s and defocusing distance of 1 mm.The results show that when defocusing distance is negative and zero,martensite transformation of the joints is more sufficient and the weld hardness is higher than that of the defocusing distance is positive,and the heat-affected zone consists of more martensite and bainite.The width of the weld does not increase indefinitely with increase of welding power and decrease of the welding speed,while welding at a low power,the appropriate defocusing distance can also increase the welding heat input,and make weld hardness increase with more sufficient martensite transformation.