焊接力学性能不均匀性对材料延性断裂影响的研究

采用缺口拉伸试样，研究了高匹配焊接接头的力学性能不均匀性对焊缝及母材金属的断裂应变、断裂时的应力三轴性及临界空穴扩张比的影响。研究结果表明：焊接力学不均匀性，对材料的延性断裂行为有强烈的影响。对于母材金属，离焊缝愈近，其断裂应变愈大，而断裂时的应力三轴性愈小。临界空穴扩张比增大。

THE STUDY ON THE DUCTILE FRACTURE OF WELDMENT WITH MECHANICAL HETEROGENEITY

In this paper, the effects of mechanical heterogeneity on the ductile fracture behaviors of base metal and weld metal were investigated using the tensile notched bars. The results show that the mechanical heterogeneity of weldment has certain effects on stress strain history, plastic strain at fracture, stress triaxiality at fracture, the critical void growth and material constant C. For the base metal, the nearer the distance is to fusion line, the larger the plastic strain at fracture is, and the smaller the stress triaxiality at fracture, the larger the critical void growth is.