Effect of Retained Austenite on the Wear Resistance of Austempered Grey Iron

Grey iron containing a small amount of Cu and Mo to improve the effect of heat treatment and microstructures were poured in to the mold and them austenized at . After austenitizing the specimens of castings were austempered , , and . The effects of matrix structures, mechanical properties and wear characteristics were investigated by austempering temperatures. Tensile strength and hardness of austempered grey iron are increased and the amount of retained austenite is decreased as austempering temperature is lower even though the amount of retained autenite in it only 4%. The amount of rolling wear loss are increased as rolling revolution is increased and wear loss of austempered grey iron under dry rolling condition is characterized by three models; initial wear, stationary wear and abnormal wear. It has been found that the amount of wear loss was increased with increasing maxium compressive stress and rolling revolution.