In-situ DIC investigation on local stress-strain behavior in creep-fatigue test of dissimilar steel welded joint

The digital image correlation technique was employed to investigate the variations of local stress–strain behavior in tensile and creep-fatigue tests for 9Cr/CrMoV welded joint. The strain concentration shifts from fine grain HAZ to over-tempered HAZ of CrMoV in tensile test. For strain-controlled creep-fatigue test, different ratcheting of sub-regions is observed, which is attributed to mismatched yielding and negative mean stress caused by...