Carburising of Low-Carbon Steel Using Carbon Black Nanoparticles

Abstract

Pack carburising is commonly used to increase wear resistance and impact toughness of low-carbon steels by increasing carbon content of the surface. Pack carburising is a time-consuming process which limits its commercial applications. The aims of present study were to increase the efficiency of pack carburising process and to decrease the time of carburising. Pack carburising of low-carbon steel was carried out by embedding low-carbon steel samples in carburising compound consisting of carbon black nanoparticles as carbonaceous matter and barium carbonate as energiser. The effect of time of carburising and carburising medium on microstructure, hardness and case depth of the samples was investigated. The samples carburised using carbon black nanoparticles showed higher hardness than the samples carburised using acetylene gas or charcoal-based carburising mixture. The case hardness of low-carbon steel increased from 140 to 275 HV after just 3 h of carburising in carbon black nanoparticles-based carburising mixture, which is 44 and 85 % higher than the samples carburised for 3 h using acetylene gas and charcoal-based carburising mixture.