摘要：Factors Affecting Toughness of High Speed Steels XU Da, YU Feng, LUO Di (Institute for Structural Materials, Central Iron and Steel Research Institute, Beijing 100081, China)Abstract:Toughness is very important for high speed steel (HSS) which affects strongly the properties and life of cutting tools. Factors affecting toughness of HSS have been studied. The result showed that the toughness of HSS is influenced by chemical compositions, steelmaking methods, inclusions, carbides and heat treatment. The toughness increases under the condition of better purity and fewer inclusions and decreases with increasing C content for the same grade of steels. W-Mo type steels are better than W type in toughness. Distribution, grain size and shape of carbides are also important factors. The toughness of powder metallurgy HSS is remarkably better than conventional HSS. Heat treatment is also another important factor, and the toughness will decrease for higher hardening temperature and lower tempering temperature. Possible ways of improving the toughness are also discussed.Key words:high speed steel;
