Hardness and Fatigue Behavior in Weldment of 13Cr-4Ni Steel Casting

Since the type 13Cr-Ni steels are easily hardened, hardness of the weldment rises without suitably post-weld heat treatment. Therefore, experiments have been made to study the effect of hardness on fatigue behavior in 13Cr-4Ni steel casting by using welded joints and as-quenched specimens. The results obtained are as follows;(1) Maximum hardness at heat-affected zone is markedly dependent upon carbon content in as-welded condition.(2) There is little difference between base metal and weld for fatigue strength of notched and smooth bar specimens in water.(3) Hardness and amount of retained austenite across the weldment are affected by heat cycles during the welding.(4) No effect of hardness levels on fatigue strength is observed in smooth and notched bar specimens.(5) Fatigue strength can be estimated from the modified GOODMANN diagram when the mean stress is applied.