A New Assessment Method Of Welding Transverse Crack Susceptibility

All kinds of welding crack susceptibility experimental methods at present mostly are evaluation of thermal crack and longitudinal crack. Few crack methods can directly evaluate the transverse cracks. The G-BOP experiment is one of the few specialized experiment methods of evaluating welding transverse crack sensitivity, but this method has many shortcomings, such as the degree of restraint after welding is not adjustable, it can only be used for comparison of crack resistance of welding material, and it requires specialized jig. This paper will design a new welding transverse crack sensitivity test evaluation method.Firstly, the specimen forms of transverse crack sensitivity test were designed. Three specimen structures were designed, namely the longitudinal groove specimen structure, unilateral transverse groove specimen structure and bilateral transverse groove specimen structure. The welding stress field of these three kinds of specimen structures were simulated by using the finite element simulation software ANSYS, and followed by experimental verification. Ultimately bilateral transverse groove specimen structure was thought as the most reasonable specimen structure.The process parameter optimization of the bilateral transverse groove specimen structure was done by using the orthogonal experiment. The orthogonal experimental results show that the length of specimen and the length of groove have a great influence on welding residual stress. The effect of the two parameters on welding residual stress was simulated and experimentally verified. The results show that the welding residual stress is generally high by adjusting the length of the groove, and the evaluation of the welding crack resistance of welding material can been realized by adjusting the specimen length.The crack sensitivity evaluation of four typical kinds of welding material was done by using the proposed bilateral transverse groove cracking test method. The evaluation results show that the welding material No.1 has the best crack resistance, followed by the welding material No.3, and the welding material No.2 has the worst crack resistance. This demonstrates that the bilateral transverse groove structure can been successfully applied in the evaluation of crack resistance of welding material. The bilateral transverse groove cracking test method was compared with G-BOP experiment and small Tekken in this article. The comparison results show that the bilateral transverse groove cracking test method and the G-BOP experiment both can been used to evaluate the welding transverse crack sensitivity. However, when the two or more welding material crack or don't crack after welding, the G-BOP experiment can't compare the crack resistance of these welding materials, but the bilateral transverse groove cracking test method can solve this problem. In addition, the paper also gives the detailed experimental procedures of this method.