多道多层堆焊成形数值模拟及残余应力研究

Study on Numerical Simulation and Residual Stress in Multi-channel and Multi-layer Surfacing Welding

本文利用Marc有限元软件对高温合金的多道多层堆焊过程进行了数值模拟,讨论了堆焊厚度和堆焊路径对焊后残余应力的影响。结果表明,堆焊厚度的增加会导致横向残余应力峰值增大,并使堆焊层局部应力的方向改变,从而受到多向应力作用,因此堆焊层在满足使用要求的前提下,堆焊厚度不易过大。同时,由于受到前后焊缝温度的影响,堆焊层间存在应力释放的现象。另外,对比了“逐道堆焊”和“逐层堆焊”过程中焊后残余应力分布情况。“逐层堆焊”相比于“逐道堆焊”所产生的残余应力分布更加均匀,且残余应力峰值更小。

In this paper,the multi-channel and multi-layer surfacing welding process of Superalloy was simulated via Marc finite element analysis software.The effect of the surfacing thickness and surfacing path on the residual stress after surfacing welding was emphatically discussed.The results showed that in the surfacing welding,the increase in surfacing thickness would lead to the increase in the peak value of the transverse residual stress and the change of the local stress direction inside the welding bead,which results in the surfacing layers are subjected to multi-directional stress.Therefore,on the premise of meeting the use requirements,the surfacing thickness is not suitable to be too large.And because of the influence of the temperature of the front and latter layers,there was a phenomenon of stress release between the surfacing layers.In addition,the residual stress distribution in the process of"channel-by-channel surfacing"and"layer-by-layer surfacing"were compared.The residual stress distribution of"layer-by-layer surfacing"was more uniform than that of"channel-by-channel surfacing",and the peak value of residual stress was smaller.