抄録
Welding is used to many structures and is important joining method in industry. Because metal is heating locally by welding, residual tensile stresses is generated in the heat affected zone. The tensile residual stress degrades fatigue strength of component, and will be one of causes of stress corrosion cracking in SUS304. Therefore it is important to decrease the tensile residual stresses. Accordingly, we have been proposed a method that adds ultrasonic vibration during welding. It can reduce the tensile residual stresses easily in a shorter time than conventional methods in SS400. In this study, reduction of the residual stress using ultrasonic vibration was studied in examination for build-up welding of thin plate in SUS304. SUS304 can keep strength in high temperature environment. Therefore, two ultrasonic vibrations that have different frequency were added to get plastic deformations that cause reduction of the residual tensile stresses by large vibrational amplitude. It is shown that using ultrasonic vibration can reduce the residual stresses in SUS304 which have high temperature property.
