Creep-Rupture Behavior of Weldments Crack growth rate for a Type 308 CRE stainless steel weldment is a function of weld and base metal creep rate

SUMMARY. Weldment strength is a func­ tion of the strengths and ductilities of the metallurgical zones of the weld geometry and the mode of loading. Weldments of the 300 series of austenitic alloys usually fail by an exhaustion of ductility in one of the zones of the weldments — that is, by a strain limit. This strain limit decreases with a lower strain rate associated with a longer rupture life and for a higher triax­ iality or constraint due to geometry or loading. Weldments can be evaluated qualita­ tively by the relative creep and rupture characteristics of the base and weld metal, but a quantitative evaluation requires an analysis of the weld geometry using the properties of the zones of the weldment. The analysis method should be verified by tests of weldments.