A study of wear resistance of carbon-free bainite and martensite in medium carbon steel

The wear resistance of carbon-free bainitic steel obtained by isothermal transformation is studied and compared with untempered martensite in this paper. The experimental steel obtained carbide-free bainite after austempered for 3 h at 310oC. The wear surface of carbon-free bainitic steel and martensite steel is mainly composed of grooves, and micro-ploughing is the main wear mechanism. The wear resistance of carbon-free bainite is better than that of martensite beyond 400 cycles. The retained austenite of the surface in carbon-free bainitic steel transforms into martensite, leading to enhance the wear resistance of the carbide-free bainite.