Morphology,microstructure and decomposition behavior of M2C carbides in high speed steel  

作　　者：Xue-feng Zhou Di Liu Wang-long Zhu Feng Fang Yi-you Tu Jian-qing Jiang 

机构地区：[1]Jiangsu Key Laboratory of Advanced Metallic Materials,School of Materials Science and Engineering,Southeast University Nanjing 211189,Jiangsu,China [2]Jiangsu Engineering Research Center of Tool and Die Steel,Danyang 212312,Jiangsu,China [3]Nanjing University of Information Science and Technology,Nanjing 210044,Jiangsu,China

出　　处：《Journal of Iron and Steel Research International》2017年第1期43-49,共7页

基　　金：funded by National Natural Science Foundation of China(51301038,51371050);Industry-Academia-Research Program of Jiangsu Province of China(BY2014127-03);Natural Science Foundation of Jiangsu Province of China(BK20141306);Key Research Program of Jiangsu Province of China(BE2016154);Jiangsu Province Key Laboratory of High-end Structural Materials of China(hsm1404)

摘　　要：The morphology,microstructure and decomposition behavior of M2C carbides in high speed steels with different chemical compositions have been investigated by scanning electron microscopy,transmission electron microscopy,electron backscatter diffraction and X-ray diffraction.The results show that the morphology and substructure of M2C carbides are very sensitive to chemical compositions of high speed steels.M2C carbides present the plate-like shape in tungsten-molybdenum steel and present the polycrystal orientation in the eutectic cell.In contrast,they show the fibrous shape in molybdenum-base steel and exhibit the monocrystal orientation.Plate-like and fibrous M2C carbides are both metastable and decompose into M6 C together with MC at high temperatures.MC nucleates inside the plate-like M2C while it is formed at the fibrous M2C/matrix interface during the decomposition process.Such differences are expected to arise from different compositions of plate-like and fibrous M2C carbides.The morphology,microstructure and decomposition behavior of M2C carbides in high speed steels with different chemical compositions have been investigated by scanning electron microscopy,transmission electron microscopy,electron backscatter diffraction and X-ray diffraction.The results show that the morphology and substructure of M2C carbides are very sensitive to chemical compositions of high speed steels.M2C carbides present the plate-like shape in tungsten-molybdenum steel and present the polycrystal orientation in the eutectic cell.In contrast,they show the fibrous shape in molybdenum-base steel and exhibit the monocrystal orientation.Plate-like and fibrous M2C carbides are both metastable and decompose into M6 C together with MC at high temperatures.MC nucleates inside the plate-like M2C while it is formed at the fibrous M2C/matrix interface during the decomposition process.Such differences are expected to arise from different compositions of plate-like and fibrous M2C carbides.

关 键 词：High speed steel CARBIDE M2C MORPHOLOGY SUBSTRUCTURE DECOMPOSITION 

分 类 号：TG142.1[一般工业技术—材料科学与工程]