EFFECT OF SENSITIZATION ON STRUCTURE AND PROPERTIES OF NON-CONVENTIONAL STAINLESS STEEL

This investigation aims to study the effect of sensitization on the microstructure and the mechanical properties of a non- conventional austenitic stainless steel with special emphasis on wear properties. A set of samples of the steel have been given sensitization treatment up to varying extents. The wear behavior of the non- conventional stainless steel is determined by using the ball on plate wear testing machine, with varying loads and sliding distances. It is observed that the height loss due to wear increases with increase in sensitization time, applied load and sliding distance. The supporting reason of these results have been discussed in terms of the depletion of solid solution strengtheners due to diffusion of these elements from the austenite matrix to the grain boundary, and the increase in carbide and nitride precipitates at the grain boundary with increasing sensitization time of the investigated steel sample. Marginal reduction in tensile strength has been attributed to possible transformation of austenite to strain induced martensite. The investigation of the worn out surface of the non- conventional stainless steel with field emission scanning electron microscope (FESEM) shows that the wear mechanism can be classified under abrasive wear.