Powder metallurgy preparation and microstructure and properties of M2 high speed steel
LUO Tao1，JIANG Wen-qing2，TONG Wei3
1School of mechanical engineering, Jiujiang Vocational and Technical College, Jiujiang 332007, China，2School of automotive engineering, Jiujiang Vocational and Technical College, Jiujiang 332007, China，3College of materials science and engineering, Xiangtan University, Xiangtan 411105, China
Abstract：M2 high speed steel powder was prepared by mechanical ball milling, studied the effect of sintering temperature on microstructure, hardness and bending strength of high speed steel, and the effect of heat treatment on microstructure and mechanical properties of high speed steel was analyzed. The results show that the particle distribution of HSS powder is uniform and the average size of HSS powder is the smallest when the milling time is 16 h, and there are no micro-holes or cracks in the samples; when the sintering temperature is 1 245℃, and the carbide is fine and dispersed. The sintering mechanism of HSS sample is solid phase sintering at 1 235 ℃,the relative density is 87.2%, and the sintering mechanism of HSS specimen is liquid phase sintering when the sintering temperature rises to 1 245 ℃ or above, and the relative density keeps above 98%. With the increase of sintering temperature, the wear weight loss of HSS specimen decreases first and then increases, and the bending strength increases first and then decreases. The hardness of the sintered samples can be further improved by quenching and tempering treatment.
2019, Vol. 29 
