Influence of Rare Earth Elements on Microstructure and Mechanical Properties of Cast High-Speed Steel Rolls

作     者：王明家 穆松梅 孙菲菲 王艳 

作者机构：State Key Laboratory of Metastable Materials Science and Technology Yanshan University Experiment Center Northeastern University in Qinhuangdao Yanming Alloy Roll Co. Ltd. Qinhuangdao 066004 China 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2007年第25卷第4期

页      面：490-494页

核心收录：

学科分类：080503[工学-材料加工工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 

基　　金：Project supported by"863"Project (2006AA03Z532) the National Natural Science Foundation of China (NSFC 50341050) 

主　　题：eutectic carbide impact toughness differential scanning calorimetry high-speed steel roll rare earths 

摘      要：The influence of rare earth （RE） elements on the solidification process and eutectic transformation and mechanical properties of the high-V type cast, high-speed steel roll was studied. Test materials with different RE additions were prepared on a horizontal centrifugal casting machine. The solidification process, eutectic structure transformation, carbide morphology, and the elements present, were all investigated by means of differential scanning calorimetry （DSC） and scanning electron microscopy energy dispersive spectrometry （SEM-EDS）. The energy produced by crack initiation and crack extension was analyzed using a digital impact test machine. It was found that rare earth elements increased the tensile strength of the steel by inducing crystallization of earlier eutectic γ-Fe during the solidification process, which in turn increased the solidification temperature and thinned the dendritic grains. Rare earth elements with large atomic radius changed the lattice parameters of the MC carbide by forming rare earth carbides. This had the effect of dispersing longpole M C carbides to provide carbide grains, thereby, reducing the formation of the gross carbide and making more V available, to increase the secondary hardening process and improve the hardness level. The presence of rare earth elements in the steel raised the impact toughness by changing the mechanism of MC carbide formation, thereby increasing the crack initiation energy.