Stress Rupture Properties of 316L(N) Stainless Steel under the Influence of Multiaxiality at Various Stress Levels

Type 316 L (N) stainless steel is one of the construction materials for Pressurized Fast Breeder Reactor, in India. The design of a material part involves various types of geometrical irregularities such as notches, holes, etc. which impose a certain degree of constraint on the deformation. The present work aims to couple one such mechanical constraint with the metallurgical changes that occur during creep. Multiaxiality is generated following the mechanical route, by machining a circumferential 60 0 V-notch. This study not only represents the case of threaded portions, but is also used for observing the notch strengthening or weakening behavior. Stress rupture curve was generated for 316L(N) SS tested at 923 K and the fractographs were explained qualitatively with multiaxial stress parameters.