JFE980S高强钢激光-电弧复合热源热模拟试验分析

Analysis on laser-arc hybrid welded joint of high strength steel JFE980S by thermal simulation test

针对JFE980S高强钢焊接热影响区的组织脆化、软化问题,采用测温仪对激光-电弧复合焊和常规MAG焊两种焊接方法焊接热循环曲线进行测定,通过测得的焊接热循环曲线,利用G leeb le3500热力模拟试验机对这两种焊接方法热影响区的焊接过程进行模拟,并对其组织、拉伸以及-20℃冲击吸收功进行了分析和测试.结果表明,激光-电弧复合焊峰值温度停留时间和t8/5,t5/3冷却时间均小于常规MAG焊;模拟的焊接粗晶区冲击韧性是常规MAG焊的两倍,不完全相变区拉伸性能比常规MAG焊提高了100 MPa以上.

The brittlement and softening of HAZ of high strength steel JFE980S were studied by thermal simulation test.After the thermal cycle curve of laser hybrid welding and MAG welding being measured,the HAZ of two welding methods were simulated by means of the thermal simulation machine of Gleeble3500,and the microstructure,tensile strength and the impact toughness at-20 ℃of the specimens were tested and analyzed.The results indicate that the residence time of peak-temperature,t8/5 and t5/3 in laser-arc hybrid welding are all less than those in MAG welding.The impact toughness of the coarse grained region in joint by hybrid welding is as two times high as that by MAG welding.The tensile strength of the incomplete phase transformation region was increased by more than 100 MPa,which was compared with the common MAG welding.