Ratcheting Fatigue Behaviour of a Sensitized Austenitic Stainless Steel (Non-Conventional)

Abstract

The aim of this investigation is to study the effect of thermal sensitization on the tensile and ratcheting fatigue behaviour of a non-conventional austenitic stainless steel (X12CrMnNiN17-7-5). The steel is known as non conventional since it contains relatively lower Ni percentage as compared to the traditional 304 grade of steel and hence cheaper to manufacture. Austenitic stainless steels are prone to thermal sensitization which has deleterious effect on the mechanical properties of any component made of it. This particular steel is potentially used in automobiles as well as in structural applications where chances of fatigue failure cannot be ruled out. One of the new research domains of fatigue studies of materials is fatigue under asymmetric cyclic loading. This phenomenon is known as ratcheting where plastic strain gets accumulated in a component and thereby reduces low fatigue life of the component. Therefore it is crucial to recognize the combined adverse effects of degree of sensitization* (DOS) and ratcheting behavior of engineering components or structures to safe guard them during their service life