Influence of Granulation on Microstructure and Mechanical Properties of New High-C-Cr Steel

The influence of heat treatment on as-cast microstructure and mechanical properties of new type high carbonchromium steel was investigated.The results show that,after quenched at 1 050 ℃ and tempered at 250 ℃,the grains of austenite refines obviously,and massive fine granular secondary carbide precipitates in austenite matrix.The heat treatment has slight effect on the morphology of the network original carbide,but the amount of carbide increases,the edges of carbide become round,and some network carbide disconnects and granulates.The hardness of the steel increases significantly,but the toughness decreases slightly,the hardness and toughness of the steel are 56.5 HRC and 4.5 J/cm2,respectively.