ABSTRACT
A new-generation unalloyed low-carbon steel (containing 0.1 wt.% C) has been recently developed by the research group of the present corresponding author through incomplete austenitisation-based cyclic ice-brine quenching possessing an exceptionally high strength (UTS = 1.7 GPa) along with elimination of a yield point phenomenon. This is attributed to the evolution of a novel microstructure that consists of fine plate martensite crystals with a dispersion of nano-sized cementite particles and clusters. The present research work is conceived as the Part II of this investigation to establish this new-generation ultrahigh strength low-carbon steel as a unique wear-resistant steel substituting the conventional dual-phase steel along with the readily awaited in-depth correlation between wear mechanism and structural evolution. The wear behaviour of heat-treated steels is investigated against an alumina disc using a pin-on-disc tribometer. The steel subjected to incomplete austenitisation-based cyclic ice-brine quenching exhibits much better wear resistance than conventional dual-phase steel. Dominant microcutting and microploughing abrasion aggravate wear loss, especially at higher load, in dual-phase steel that inherently possesses lower matrix hardness. But, very high-surface hardness is attained in the incomplete austenitisation-based cyclic ice-brine quenched steel by virtue of a significant strain hardening of martensite matrix in between hard nano-sized cementite particles. Besides, the wear rate is not allowed to shoot up even at the highest load through the generation of hard abrasion-resistant tribo-oxide layer of Al2FeO4. This envisages an advent of novel wear-resistant steel as a better substitution for the dual-phase steel.
Acknowledgement
The authors acknowledge the necessary support of Dr Kalyan Kumar Chattopadhyay, Professor, Department of Physics and Director, School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, India, for providing Raman spectroscopy facility.
Disclosure statement
No potential conflict of interest was reported by the authors.