Effect of Notch on Creep Behaviour of 316 L(N) Stainless Steel

Abstract

Creep tests on 316 L (N) stainless steel notched specimens with varying notch acuity were carried out and notch effect was studied. Various multiaxial stress states were generated by providing circumferential V-notch. The tests were car ied out under load of 300 MPa and at 873 K temperature. The creep life of notched specimens was found to be in the range between 1500-3800 hours. Material exhibited notch strengthening effect which was attributed to the multiaxiality resulting into stress distribution during creep. Mixed mode of fracture was observed. The scanning electron micrographs revealed that, the location of transition from brittle to ductile mode was pulled in towards center of cross-section as the degree of constraint was reduced. Finite element analysis results showed that, the stress distribution was a local event in the highly constrained specimen and a global event for specimen having lower constraint.