Effects of mischmetal addition on phase transformation and as-cast microstructure characteristics of M2 high-speed steel  

作　　者：曲明贵 王振华 李慧 吕知清 孙淑华 傅万堂 

机构地区：[1]State Key Laboratory of Metastable Materials Science and Technology,College of Materials Science and Engineering,Yanshan University [2]College of Mechanical Engineering,Yanshan University [3]College of Sciences,Yanshan University

出　　处：《Journal of Rare Earths》2013年第6期628-633,共6页稀土学报（英文版）

基　　金：supported by National Natural Science Foundation of China(51171161,51101137);the Major Projects of the State Nuclear Power(2011ZX06004-016);Science Fund for Distinguished Young Scholars in Hebei Province(E2011203131)

摘　　要：The influence of mischmetal （Ce-La） addition on phase transformation and as-cast microstructure characteristics of M2 high-speed steel （HSS） was investigated using Thermo-Calc software, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy with energy dispersive spectrometry. The results showed that the measured phase transition points of M2 HSS were broadly consistent with the theoretical results. After mischmetal addition, the liquidus peak temperature, the peak temperature of the eutectic precipitation of M6C and MC were all increased, especially for the M6C which was affected significantly and increased about 31 °C. The contents of Mo and V in the eutectic carbide decreased and that of Fe increased, while in the matrix, the Mo, V and Cr contents all increased slightly. Furthermore, the microstructure of as-cast dendrite and ledeburite were refined, the total eutectic carbide content decreased and distributed into a discontinuous network, the lamellar spacing of M2C was reduced and the lamellae became thinner.The influence of mischmetal （Ce-La） addition on phase transformation and as-cast microstructure characteristics of M2 high-speed steel （HSS） was investigated using Thermo-Calc software, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy with energy dispersive spectrometry. The results showed that the measured phase transition points of M2 HSS were broadly consistent with the theoretical results. After mischmetal addition, the liquidus peak temperature, the peak temperature of the eutectic precipitation of M6C and MC were all increased, especially for the M6C which was affected significantly and increased about 31 °C. The contents of Mo and V in the eutectic carbide decreased and that of Fe increased, while in the matrix, the Mo, V and Cr contents all increased slightly. Furthermore, the microstructure of as-cast dendrite and ledeburite were refined, the total eutectic carbide content decreased and distributed into a discontinuous network, the lamellar spacing of M2C was reduced and the lamellae became thinner.

关 键 词：M2 high-speed steel mischmetal phase transformation as-cast microstructure CARBIDE rare earths 

分 类 号：TG142.45[一般工业技术—材料科学与工程] TG146.21[金属学及工艺—金属材料]