能量配比对激光-MIG复合焊接头残余应力的影响

采用不同激光/电弧能量配比(QRLA)对8 mm厚Q345钢板进行激光-MIG(metal inert gas,MIG)复合焊接,研究了QRLA对复合焊接头的截面形貌和显微组织的影响,并分析了不同QRLA下焊接过程的温度场和接头残余应力分布的变化规律.结果表明,随着QRLA增大,熔宽显著下降,焊接过程的最高温度略有升高...

Effect of Heat Input Ratio on Residual Stress in Hybrid Laser-MIG Welded Joint

Hybrid laser-MIG welding of 8 mm thick Q345 steel plates was carried out using different laser-to-arc heat input ratio(QR_LA).The effects of QR_LA on the cross-sectional macro-morphology and the microstructures in the hybrid welded joint were investigated.Development of temperature field distribution in the welding process and residual stress distribution in the welded joint under different QR_LA were also analyzed.The results show that the weld bead width decreases while peak temperature in the welding process increases with elevated QR_LA.The microstructure of coarse grained HAZ is mostly martensite due to the high welding speed,and the amount of martensite increases with elevated QR_LA.The stress levels of equivalent residual stress,longitudinal residual stress,transverse residual stress and through-thickness stress all reduce moderately as laser power increases with QR_LA in the range of 0.72~1.0.However,the stress levels of the four stresses increases slightly as laser power increases with QR_LA in the range of 1.0~1.18.