Effect of Grain Refinement on Tribological Study of Low Carbon Steel

Tribological characteristics of low carbon steel (LCS) have been investigated on as-received coarse grains of 67 μm size and ultrafine-grained (UFG) microstructure of 0.2 μm size, which was prepared by equal-channel angular pressing (ECAP). Two-body abrasion tests have been carried out against silicon carbide abrasive papers at various loads. Furthermore, solid particle (silica sand) erosion tests were also conducted at normal particle impingement angles at various impact velocities. The ECAP process improved the resistance to abrasive and erosion wear of UFG LCS as compared to that of as-received coarse-grained steel. The abrasive and erosion wear resistances of UFG LCS were improved under severe conditions. The abrasive wear mechanism of as-received coarse-grained LCS was governed by micro-cutting, whereas it was microploughing in UFG LCS. The mechanism of material removal in erosive wear was brittle in as-received material in contrast to ductile in UFG steel.