Design of low hardness abrasion resistant steels

Abrasion resistant steels in combination with a good formability and a desirable balance of strength and ductility are in high demand for industrial applications. Current developments of high end abrasion resistant steels are mostly oriented on the high hardness martensitic concept following the hypothesis that the abrasion resistance holds a monotonous relationship with hardness. However, various experimental observations have suggested that the high hardness of martensite does not guarantee a high abrasion resistance comparing to multiple phase steels with a relative lower hardness but better ductility/toughness, and the brittle nature of martensite often leads to undesirable machinability and other inferior in-use properties. The present paper reviews the effects of various microstructural aspects on the abrasion resistance and attempts to define a desirable microstructure for low hardness abrasion resistant steels: a dual phase matrix strengthened by retained austenite via the TRIP effect. Given a detailed description of the desirable microstructure, its characteristics can be converted to quantifiable criteria and be implemented in a computational genetic alloy design approach to design alloy compositions and heat treatments for new families of ductile yet abrasion resistant steels.