基于粘弹塑性理论局部焊后热处理新的评价标准的研究

A direct quantitative method and its software system has been proposed successfully to assess the local post weld heat treatment (PWHT) based on the visco-elastic-plastic FEM. Using this method, the mechanical behavior of local PWHT, effectiveness of the stress relief and the optimum parameters can be found. Two criteria are proposed for assessing the effectiveness of local PWHT. One is the residual stress criterion which is related with the relaxation of residual stresses, the other is the criterion of temperature different in soak band width which is more related to the improvement of the materials properties. In addition, the criterion for assessing the local PWHT of a 3-D tubular joints have also been recommended. The computed results are agree well compared with the experiments. This study has the important siganificance and receives great concerns from the researchers in China and abroad.

引入考虑高温蠕变的粘弹塑性有限元理论和方法，对局部焊后热处理全过程的温度和力学行为作直接的跟踪研究。定量阐明各种参数对局部热处理应力消除效果的影响，并加以严格的实验验证。在此基础上对各国现行标准不一和存在的问题从机理上作出评判，并提出新的评价方法和标准。