EFFECT OF THERMAL HISTORY BY POST-WELD HEAT TREATMENT ON RESIDUAL STRESS RELAXATION AND DEFORMATION BEHAVIOR OF STEEL MEMBER

Abstract

When welding is considered as a joining method for repair and reinforcement of steel structures, welded joints have disadvantages such as influence of residual stress on fatigue strength and embrittlement of heat affected zone by welding heat input. Post-weld heat treatment is an effective method to solve these problems. However, civil steel structures assembled by thin plates are possible to be deformed easily by PWHT. For investigating residual stress change and deformation behavior of welded thin plates by PWHT, a series of experiment and analysis were carried out. A condition of PWHT for reducing residual stress and out-of plane deformation was proposed with considering generation mechanism of them.