Since the 1980s, cryogenic treatment has been successfully used to optimize cemented carbide. Many studies have shown that cryogenic treatment has a certain positive impact on the mechanical properties, wear resistance, cutting performance, microstructure, and residual stress conditions of cemented carbide. Through continuous exploration by researchers, a series of practical values have been obtained. and conclusions of scientific significance.
(1) Cryogenic treatment can improve the bending strength, wear resistance and cutting performance of cemented carbide, thereby effectively extending the service life of cemented carbide tools. By analyzing the influence of cryogenic treatment process parameters on the mechanical properties of cemented carbide, it is believed that the optimization effect of cryogenic treatment does not change linearly with the decrease of cryogenic treatment temperature and the extension of holding time. For specific grades of cemented carbide, there is an optimal cryogenic treatment process, which can achieve the best optimization effect at low cost.
(2) The main effects of cryogenic treatment on the microstructure of cemented carbide are: ① changing the grain morphology of the hard phase – WC; ② promoting the martensitic transformation of the bonding phase; ③ fine carbide particles (eta phase) in Dispersed and precipitated on the material matrix.
(3) The martensite transformation of the bonding phase, the precipitation of fine carbides and the increase of residual compressive stress on the material surface after cryogenic treatment can significantly improve the strength and wear resistance of cemented carbide. Therefore, the improvement of the macroscopic properties of cemented carbide is the result of the combined effects of phase transformation strengthening and stress strengthening.
Post time: Mar-06-2024
