A comparative analysis of abrasive wear behaviors and mechanisms of pearlitic and carbide-free bainitic steels for grinding mill liners under varied impact loads

Abstract

A mill liner is a critical wear-resistant component in mineral crushing equipment, and its main failure mode is impact abrasive wear. This study examined carbide-free bainitic steel and pearlitic steel, which are commonly utilized in commercial liners. The wear behavior and wear mechanism of the two wear-resistant steels under different impact loads were revealed through characterization and testing of their microstructure, mechanical properties, and impact abrasive wear performance. The results indicated that under impact loads of 1, 3, and 5 J, the impact abrasive wear resistance of the carbide-free bainitic steel was superior to that of the pearlitic steel. The wear resistance of the pearlitic steel increased nearly linearly with increasing impact load, whereas the wear resistance of the carbide-free bainitic steel exhibited a nonlinear trend, initially decreasing and then increasing with higher impact loads. Under an impact load of 1 J, both samples primarily exhibited micro-cutting as the main wear mechanism, whereas the pearlitic steel demonstrated additional features such as micro-indentation and spalling. Under impact loads of 3 and 5 J, the main wear mechanisms for both samples were micro-cracking and micro-fatigue caused by abrasive impact. Compared with pearlitic steel, carbide-free bainitic steel demonstrated better resistance to delamination, especially under higher impact loads. This study provides guidance for designing tailored liner materials for different impact loads and lays theoretical foundation for extensive application of bainitic steel liners.