Effect of post oxidation on the fretting wear behavior of liquid nitrided En 24 steel

Fretting wear is a low amplitude reciprocating sliding wear that is observed in many machine elements. Effect of post oxidation on fretting wear behaviour of liquid nitrided structural steel, En 24, against the hardened and tempered En 31 steel was investigated. Oxidation treatment carried out at a temperature of 773 K leads to formation of stable oxide layer over the compound layer. The oxide layer mainly consists of magnetite (Fe3O4) and hematite (Fe2O3) phases. Fretting wear studies were carried out using cylindrical specimens at constant slip amplitude 60 μm and at different normal loads. The coefficient of friction against number of run was plotted. The effect of post oxidation duration on fretting wear behavior was reported in the form of fretting wear loss and friction coefficient. The thickness of oxide layer formed affects the friction and wear characteristics under fretting conditions.