Capability of nodular eutectic and austenite–bainite polyphase structure to resist impact abrasive wear

Abstract

Wear behavior of austenite–bainite polyphase steel with nodular eutectics subject to impact abrasion has been investigated by means of transmission electron microscope (TEM), scanning electron microscope (SEM) and MDL wear tester. Results indicate that the nodular eutectic effectively prevents the penetration of the abrasive into the worn surface, and reduces the microcutting of the abrasive on the worn surface. The worn surface layer has a good match of strength and toughness because of strain-induced martensite, dislocation, twin crystal and deformed bainite structure, which can make the worn surface layer bear more plastic deformation and the impacting of the abrasive under low and medium impact working condition. However, there is amorphous structure and superfine grain in the worn surface, strain-induced martensite, dislocation, twin crystal and deformed bainite structure in the worn subsurface layer under high impact. As a result, the hardness from the subsurface layer to the worn surface of the steel increases gradually, which can effectively resist the impacting and the penetration of the abrasive. The austenite–bainite polyphase structure with nodular eutectics is a promising structure in resisting abrasive wear as compared with a bainite structure, bainite structure with nodular graphites and an austenite structure with nodular eutectics.