Tempering temperature dependence on the microstructure, mechanical properties and wear behaviour of a novel high chromium cast iron

The microstructure, mechanical and wear behaviour of a high chromium cast iron was investigated with various tempering temperatures (200°C, 280°C, 360°C, 440°C) by SEM, TEM and EBSD. Both of primary M7C3 and secondary carbides increasingly coarsed as temperature increasing, contributing to the best mechanical properties as tempered at 200°C. The highest strength and hardness produced highly deformed layers, including the SFs locks in M7C3 and strong work-hardening in matrix, retarding dislocations movement and hindering materials peeling, thus improving the wear resistance as tempered at 200°C. Besides, The wear mechanisms shifted from abrasive and adhesive wear to oxidative and fatigue wear as temperature raising. The optimal heat treatment was ascertained to provide further instructions for the development of advanced cast irons.