Heat Treatment Process of High Chromium Cast Iron Grinding Ball

A heat treatment processing was studied on a high chromium cast iron that contain trace alloy elements Mo,V and Nb.The quenching temperature was 980 ℃,the tempering temperature was 400 ℃ and 600 ℃.The microstructure of substrate was the Martensite after quenching in water from 980 ℃.The microstructure was transformed to Troosite and Sorbite after tempering at 400 ℃ and 600 ℃ respectively.According to the hardness and wear resistance analysis,the quenched specimens with the highest hardness and the lowest wear loss.After 400 ℃ tempering treatment,the hardness decreases to 62.8 HRC and the wear loss improves 18.2% than quenched state.After 600 ℃ tempering treatment,the hardness decreases to 57.6 HRC and the wear loss improves 30.3% than quenched state.Considering the usage status of cast iron ball,the best heat treatment process was quenched at 980 ℃ and tempered at 400 ℃.