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

Abstract

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.