Wear Behavior of High Chromium Cast Iron and Heat Treated AISI P20 Steel Under Round and Sharp Counterbodies

Abstract

The working surfaces of hammer made from High Chromium Cast Iron (HCCI) underwent a serious material loss during barite rock crushing within only one week. In order to reduce the hammer damage, this research study suggests the substitution of HCCI by a heat treated AISI P20 steel (AISI P20T). For this reason, the microstructure of both materials was identified. A series of mechanical and tribological tests was conducted to compare the mechanical strength as well as the wear resistance of both materials.The microhardness and elastic modulus of the studied materials were measured using microindentation test. The resistance against abrasive wear of both metals were evaluated by the use of a rounded and a spheroconical couterbodies. Indeed, a rotating sliding test was performed using alumina ball while a multi-pass scratch test was conducted using Rockwell type-C indenter. Based on microscopy observation, HCCI microstructure consists of martensite and eutectic carbide while AISI P20 shows a total martensite microstructure. The tribological results reveal that AISI P20T is characterized by an excellent wear resistance contrary to HCCI showing very poor wear endurance. It has been proved that the tribological behavior of both materials is closely related to their microstructure and then their mechanical characteristics.