Using heat sink technology to decrease residual stress in 316L stainless steel welding joint: Finite element simulation

摘要

316L type stainless steel is widely used in chemical industries due to its excellent resistance to corrosion. But the welding residual stresses have a great effect on stress corrosion cracking. This paper used finite element method to study the effect of heat sink on residual stress. The effects of contact length and the average heat transfer coefficient on residual stress have been investigated. It is found that the heat sink technology can decrease the residual stress greatly. Compared to the model without heat sink, 20% of the peak longitudinal stress has been reduced. The heat sink decreases the dwell time during cooling from 850℃ to 400℃, which is helpful to decrease the risk of sensitization of 316L stainless steel. With the contact length increase, the transverse stress is decreased. Further increase of the contact length has no positive effect on reducing the longitudinal stress. With the average heat transfer coefficient increase, the transverse stress is decreased greatly while the longitudinal stress decreases slightly, and some tensile residual stresses have been changed to compressive in some zone.