Microstructure and fracture toughness of electron beam welded joints of 30CrMnSiNi2A steel

Two post-weld heat-treatments (PWHT), 900°C oil quenched and low temperature tempered (PWHTA) and high temperature tempered and then 900°C oil quenched and low temperature tempered (PWHTB), are employed to treat the weldment. Then the effect of two post-weld heat-treatment processes on the microstructure, mechanical properties and fracture toughness of electron beam welded joints of 30CrMnSiNi2A steel have been discussed. The results show that, after two lands of PWHT the microstructure and hardness at every tones of EBW joints are nearly same. Although the welds have good mechanical properties, fracture toughness of both weld and heat-affected gone (HAZ) is low, the CTOD values of welds are comparatively higher than that of HAZ. Microstructure and fracture toughness of two EBW joints have no evident differences.