On the unique microstructure and properties of ultra‐high carbon bearing steel alloyed with different aluminum contents

Abstract

In this study, ultra‐high‐carbon steels with 1.4% carbon content alloyed with three different aluminum contents, 2.0%, 4.0% and 6.0%, were studied on their tempering stability and temperature resistance. The results showed that the addition of Al significantly enhanced the tempering stability and temperature resistance of ultra‐high‐carbon steel. The addition of Al in-hibited the transformation of ε‐carbide to cementite, suppressed the transition of martensite to ferrite and thus, endowed ultra‐high carbon steels to maintain very high hardness during tempering within a wide range of temperature up to 500 °C. The present work provides a useful basis on which to develop bearing steel materials with low density and high hardness.