Effect of different strengthening methods on rolling/sliding wear of ferrite-pearlite steel

The object of this paper is to study the influence of different strengthening methods on wear resistance of ferrite-pearlite steel. Rolling/sliding wear tests were conducted for five railway wheel steels which were hardened by carbon addition, solid solution strengthening and precipitation strengthening, respectively. Wear rate, subsurface plastic deformation and strain-hardening of tested steels were examined. The test results show that wear resistance of ferrite-pearlite steel is improved by both carbon addition and solid solution strengthening, whereas it is deteriorated by precipitation strengthening. Wear resistance of ferrite-pearlite steel depends on the worn surface hardness that is influenced by bulk hardness and strain-hardening. Strengthening methods increase the bulk hardness to different extents, where the highest and lowest bulk hardness increments are obtained by the solid solution strengthening and precipitation strengthening, respectively. The strain-hardening is promoted by carbon addition, while it is reduced by solid solution strengthening and precipitation strengthening where precipitation strengthening makes a greater reduction in strain-hardening. Strain hardening of ferrite-pearlite steel is reduced by a high content of proeutectoid ferrite with a low ductility, which is caused by solid solution strengthening and precipitation strengthening.