Grain boundary segregation of antimony in heat affected zones during welding thermal cycles for a Cr–Mo low alloysteel

Abstract

Grain boundary segregation of Sb in heat affected zones during welding thermal cycles is examined using field emission gun scanning transmission electron microscopy (FEGSTEM) for an Sb-doped Cr–Mo low alloy steel. A Gleeble-1500 thermomechanical simulator is used to simulate the welding heat affected zone with a peak temperature of 1320°C for heat inputs of 36, 60 and 100kJ/cm. The results show that non-equilibrium segregation of Sb occurs during thermal cycles and critical welding heat input is found to be between 36kJ/cm and 100kJ/cm, at which the maximum segregation of Sb may be obtained during corresponding thermal cycling. If possible, this critical heat input should be avoided in engineering practice.