Surface modification and enhanced wear performance through severe shot peening treatment in 316L stainless steel manufactured by metal injection moulding

Abstract

This study investigates the micro-to nanostructural evolution hardness and linear reciprocating wear resistance using Al2O3 ball as a counterpart of 316L stainless steel fabricated by the metal injection moulding (MIM) process with and without severe shot peening treatment (SSP). SSP treatment led to a slight increase in Ra but a decrease in Rz and the formation of nanocrystalline surface ??-martensite and mechanical twin. The subsurface hardness increased significantly. Surprisingly the coefficient of friction remained constant (0.37�56) and depended solely on the testing load despite alterations in surface roughness and subsurface microstructure due to SSP treatment. Furthermore wear resistance notably improved under 10 N and 20 N loads attributed to the surface modification by SSP treatment but showed no significant difference at 30 N. The wear mechanisms including abrasive adhesive wear and oxidative wear remained similar with adhesive and oxidative wear dominating at lower testing loads (10� N). However with a testing load of 30 N the strengthening effect of SSP treatment was surpassed leading to the dominance of severe adhesive and oxidative wear. Consequently the wear resistance exhibited insignificant differences between specimens before and after SSP treatment. ? 2024 The Authors