Study on the surface microtexture microscopic friction and wear characteristics of 304 stainless steel

Abstract

In order to reveal the friction behaviour and wear mechanism of nanoscale textures on the friction pair of 304 stainless steel, molecular dynamics simulations were firstly used to investigate the effects of smooth and textured surfaces on the tribological properties of the stainless steel substrate, and then focus on the effects of sliding velocity and depth on the surface morphology, mechanical force, friction coefficient, anisotropy, stress, temperature and dislocations of the textured substrate. The results show that the temperature, friction, stress, and dislocation line length of the textured surface are relatively smaller than those of the non-textured surface, and the textured surface has a smaller and more stable friction factor, which ultimately leads to a reduction of the friction factor by about 0.090. When the sliding distance is 120 Å, the number of defective atoms in the textured substrate is reduced by 12.9%, and its anisotropy is more stable. At the same indentation depth, the average friction coefficient, temperature and anisotropy increase significantly with increasing sliding velocity. The average friction coefficient is maximum when the sliding velocity is increased to 400 m s−1, with a value of about 0.833. The sliding friction, friction coefficient, dislocation line length, number of defect atoms, number of stacked atoms, stress, temperature and anisotropy factor increase with increasing depth of abrasive indentation. The average friction coefficient is minimum at a sliding depth of 4 Å, with a value of about 0.556, and the number of defective atoms is reduced by 83.2%. This indicates that textured surface treatment of 304 stainless steel and selection of appropriate sliding parameters can effectively reduce the wear during the friction process and improve the wear resistance of the substrate.