Notably improved mechanical properties via introducing a short austempering treatment on low-carbon martensite steel

A novel process, quenching to a low temperature far below Ms followed by a short austempering treatment (Q-A-T), was carried out on a low-carbon martensite steel. Results show that a notably improved toughness without losing strength was obtained on the Q-A-T specimen as compared with the oil-quenched specimen. Microstructure analyses reveal that the Q-A-T specimen consisted of low-carbon martensite, high carbon–low temperature bainite and retained austenite. The fast quenching process effectively refined the martensite plate and the austempering process introduced the high strength phase–low temperature bainite, both of which are responsible for the improved mechanical properties.