Abstract

The present study aimed to examine the low cycle fatigue properties at continuous welded areas and at the arc start and end points of butt welded low-alloy steel. To this end, ASTM A633 grade D steel was butt welded by manual arc welding. Low cycle fatigue test, and microscopic optical metallography were performed on the samples. The results showed that inappropriate welding thermal cycle led to coarse grained ferrite and Widgetman Stretton ferrite structures at the arc start and end points. At these points, due to coarse grained boundary ferrite structures, inclusion and porosity of crack-initiation phenomenon were intensified. In addition, Widgetman Stretton ferrite structures accelerated cracks growth rate. The results indicate a decrease in strength of samples.