TIG熔修后T形接头的焊接残余应力及消除

用红外热成像仪测量了P355NL1钢T形接头在焊接过程中的温度场分布,得到焊接过程的温度循环曲线,并且与有限元方法模拟的温度场结果吻合,验证模拟计算的准确性;使用盲孔法,测量了T形板焊接MAG焊后、TIG熔修后以及热处理后的残余应力;采用间接法利用温度场计算结果计算了T形接头试板焊接残余应力场,模拟结果与实际测量的残余应力趋势相符.结果表明,TIG熔修能一定程度的降低焊缝中心的残余应力,但增大了熔修区域的残余应力;而通过整体热处理能有效地消除熔修带来的大部分残余应力,但仍有部分残余应力存在.

Welding residual stress in T-joint after TIG dressing and its relief

The welding temperature field in T-joint P355NL1 steel plates was measured by using an infrared thermography, and the welding thermal cycle curves were obtained, which have good agreement with the simulation results.The residual stress in T-joint plates was measured by blind-hole method after MAG welding, TIG dressing and heat treatment.The residual stress in T-joint plates was calculated according to the simulated welding temperature field, and the calculated results correspond with the experiment results.The results showed that the method of TIG dressing could lower the residual stress in seam center area to some extent, but the residual stress in remelted area increased.However, the overall heat treatment can effectively relieve residual stress caused by TIG dressing, but there is still partial residual stress in joint.