Studies on Fatigue Crack Growth around Weldment in SUS304 Stainless Steel. Prediction of Crack Growth Behavior in Residual Stress Field

摘要

Many failures in welded structures are caused due to the initiation and propagation of cracks which are induced by the high welding residual stress. Up to now, it has been known that the welding residual stress has many influences on the crack initiation and propagation, but the problems of the influence of welding residual stress on the structural integrity are not so clear to date because of the difficulty of its quantitative evaluation and of the analysis on the interaction between the residual stress and crack growth. Recently, an analytical procedure to predict the fatigue crack growth based on fracture mechanics has been introduced in some inspection standards and criteria for the purpose of preventing the brittle fracture. It seems important to perform the accurate crack growth predictions as regards the valid application of the above standards, as well as the practice of reliable defect sizing. Therefore it is one of the important subjects to evaluate the influence of welding residual stress on the fatigue crack growth. Relaxation and redistribution of the residual stress will be caused when crack extends in the residual stress field. Besides, an interaction effect between the fatigue stress and residual stress will be caused at the same time. In this report is described a simple prediction on the fatigue crack growth behavior in the residual stress field firstly, and t. (Atomindex citation 14:749323)