A Study on Residual Stresses of Dissimilar Welding Joints
Bahaa ZAGHLOUL, Abdel-Monem EL-BATAHGY, Alber SADEK, Mohamed EL-SHENAWY
This research work focused on different types of dissimilar weld joints commonly used in refineries and chemical industries to investigate the magnitude, type and distribution of welding residual stresses in weld metal and HAZ at both face and root sides. These joints were combined from mild steel, stainless steel types 304 and 316, and Incoloy 800. For comparison, similar weld joints for each material were also studied. Stress relaxation or sectioning technique was used for welding residual elastic strain measurements using electrical strain gauges.
The results of this study have shown that measured elastic strains of both face and root sides were different and this difference increased with the increase in plate thickness. Welding residual stresses of HAZ did not depend on joint type, it depended only on properties of base metal.
A considerable difference in the value of welding residual stresses between similar and dissimilar pipe weld joints was obtained. However, both have shown almost similar trend of stress distributions.