Sliding wear of electro-carburized mild steel with different microstructures

ABSTRACT The tribological behaviour of carburized steel with different microstructures, produced by varying the carburization time was investigated. Increasing the carburization time from 1 h to 3 h resulted in higher hardness and greater martensite content, which had a stronger tendency to form a better anti-wear oxide. In turn, these improved properties enhanced the adhesive wear resistance and delayed the occurrence of fracture. Longer carburization also resulted in the formation of expanded martensite and shallower grain boundaries with fewer precipitates, which further enhanced the fracture resistance of the steel. Larger scale fracture occurring on steel carburized for 1 h resulted in cracked WC grains, the formation of more undermined WC grains and cavities (due to the removal of WC grains) and severe grooving on the cemented carbide counterbody. In conclusion, this carburization process was effective in enhancing the wear resistance of mild steel which subsequently reduced the wear of the cemented carbide counterbody. GRAPHICAL ABSTRACT