基于固有应变法筒体对接多道焊焊接变形的预测

Prediction of distortion based on inherent strain method in multipass girth-butt welded pipes

对于全焊接阀体球阀,由于最后一道工序是焊接,为了确保焊后阀芯的转动和阀门的密封,焊接变形应该严格的控制,选择一个有效的方法准确地预测焊接变形,为焊前阀体的加工提供参考数据。采用了基于固有应变理论的有限元法预测与阀体结构相似的筒体对接多道焊的焊接变形。对于多道多层焊,轴向变形采用了分层计算的方法,径向变形进行一次计算。与试验测量的结果比较,计算值与测量值比较吻合,验证了固有应变法的准确性及可靠性,为阀体焊接工艺参数的优化和焊接结构的加工提供了重要的参考依据。

For full welded body ball valve,the last working procedure is welding,and welding distortion must be controlled strictly in order to assure spool rotation and valve seal.Therefore,prior to welding an efficient method must be selected to predict welding distortion accurately to provide preferences for the production planning of full welded body ball valve.Finite element method based on the inherent strain theory was selected to predict welding distortion in multipass girth-butt welded pipes which is similar to valve structure.For multi-layer and multipass welding,the axial distortions of each layer were calculated respectively and the radial distortion was calculated for one time.Through the comparison of welding distortions between calculated and measured,both results are very anastomotic,which proves the accuracy and reliability of the inherent strain method and provides important references for the optimization of welding parameters and the production planning of full welded body ball valve.