Abstract
The main objective of this study is to investigate the possible role of residual stress redistribution on fatigue crack propagation behavior, caused by crack extention itself initially through residual tensile stress field. Experiments of both fatigue crack propagation and sawcut simulating a propagating crack were carried out on HT80 steel components on which melt running of electron beam welding was performed to induce residual stress field. Both experimental results were compared and reviewed from a viewpoint of residual stress redistribution. Clear differences between the results of both experiments were not observed, and the common feature recognized from the results was the residual stress concentration consecutively occurred in the vicinity of crack tip even the situation that the crack propagated to the region initially residual compressive stress existed. Prediction method that attempts to account for the observed results are proposed.
