Volume 17, Issue 4 (July 1989)
Determination of the Loading Rate Needed to Obtain Environmentally Assisted Cracking in Rising Load Tests
A method is proposed to calculate the loading rate needed to induce environmentally assisted cracking (EAC) in precracked specimens tested under rising load. The procedure applies to materials that fracture by ductile tearing under inert conditions and requires some EAC data, although these may be obtained from one of several sources. A fundamental basis is provided to explain why the rising load test can serve as an accelerated test. Application to a medium strength steel in synthetic seawater and a pipeline steel in a carbonate/bicarbonate solution shows good results: EAC was exhibited and a close estimate of the threshold stress intensity factor for sustained load was obtained in less than one tenth the time required by conventional methods.