Hardness, tensile and wear behaviour of a nonconventional austenitic stainless steel upon sensitization

Abstract

The objective of this dissertation is to study the effect of sensitization on the mechanical properties such as hardness and tensile strength of a non-conventional austenitic stainless steel with special emphasis on wear properties. A set of samples has been solution annealed by soaking the steel at 1050°C followed by water quenching. On the other hand, a total of four sets of samples of the steel have been given sensitization treatment by holding at 7500C temperature for different soaking time periods ranging from 1 to 7 hours followed by water quenching. The microstructures of both the solution annealed as well as sensitized samples have been observed by optical microscope. The mechanical testing such as microhardness and macrohardness as well as tensile testing of each specimen has been performed. The wear behaviour 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 hardness and yield strength of the investigated stainless steel sharply decreases with increase in sensitization time, whereas the tensile strength of this steel decreases marginally with sensitization time. It is also observed that the ductility values of the specimens decrease with increase in sensitization time.