Effect of welding residual stresses on corrosion ofST-52 steel part in saltwater

Residual stresses are stresses that remain in a solid material after the original cause of the stresses has been removed. Welding is one of the most significant causes of residual stresses which typically produces large tensile stresses in the weld. In this study, the effects of welding residual stresses on corrosion of ST-52 steel parts in salt sea water environment were analyzed. Many factors can cause residual stress. In this research, three main factors such as Amperage, Welding travel speed and preheating temperature each in three levels were selected as effective parameters. To decrease the number of experiments, Taguchi experimental design was applied. Samples of ST-52 steel were welded according to an L9 Taguchi orthogonal array, then were put in salt seawater environment and their corrosion rate were measured by weight lost tests The results of analysis of variance (ANOVA) showed that amperage and welding travel speed were the most important effective parameters, respectively and preheating temperature did not influence the corrosion rate significantly.

Keywords:

Welding , Residual stress , Corrosion , ST-52 , Taguchi experimental design