Propagation of fatigue cracks from surface flaws in austenitic Type4 316 butt welds

Abstract Fatigue crack propagation from surface flaws in butt-welded Type 316 joints has been studied at 550°C. The effect of position of the flaw, mean stress and post-weld heat treatment have been included together with an assessment of the validity of using small compact tension specimens to predict rates of growth in large joints. It is implied that the residual stress arising from welding is not necessarily additive to the applied stress during fatigue crack propagation in austentic weldment. However, appropriate care should be exercised over simulating the degree of constraint existing in a given situation.