Application of quenching-partitioning-tempering process and modification to a newly designed ultrahigh carbon steel

作者：Liu, S. G.; Dong, S. S.; Yang, F.; Li, L.; Hu, B.; Xiao, F. H.; Chen, Q.; Liu, H. S.^*

来源：Materials & Design, 2014, 56: 37-43.

DOI：10.1016/j.matdes.2013.10.094

• Microstructure
• Ultrahigh carbon steel
• Quenching-partitioning-tempering
• Modifier mixture
• Abrasion resistance

The applicability of quenching-partitioning-tempering (Q-P-T) process to an ultrahigh carbon steel (UHCS) has been investigated by means of optical microscopy (OM), scanning electronic microscopy (SEM) combined with energy-dispersive spectrometry (EDS), X-ray diffraction (XRD) and mechanical property tests. The molten steel was modified with a multi-component modifier-rare earth and a low melting point alloy (Al-Bi-Sb) before casting into iron molds. Observations showed that the carbide exists as partly isolated and fine blocky structure in as-cast microstructure, indicating good effect of modification. After the Q-P-T treatment, carbon was partitioned into austenite from martensite, creating a mixture of carbon-depleted martensite, carbon-enriched retained austenite and fine carbides. This kind of microstructure leads to a much higher impact toughness, 32 J/cm(2), in comparison with the value, i.e., no more than 20 J/cm(2), of the conventional quenching and tempering (Q-T) treatment at the same hardness level. Furthermore, wear-resisting property of the steel has also been investigated. It showed that the Q-P-T treated steel has better abrasive wear resistance, about 18% increased, compared with the Q-T treated alloy under high load conditions.

• 出版日期2014-4
• 单位中南大学