Effect of cooling rate on martensitic transformation initiation temperature and hardness of super high strength martensitic steel

doi:10.13251/j.issn.0254-6051.2022.07.032

Abstract

Abstract: Martensite transformation initiation temperature (Ms temperature) of martensitic steel with cooling rate of 20-70 ℃/s was measured by thermal expansion method, and its effect on hardness of the tested steel was studied. The results show that the increase of cooling rate enhances the strength of austenite, improves the thermal stability of austenite, and then decreases the initiation temperature of martensite transformation. At the same time, a higher cooling rate is more likely to cause lattice distortion, increase the dislocation density, increase the degree of undercooling and refine the effective grain size, which increases the hardness of the tested steel.

Key words: martensitic steel, cooling rate, Ms point temperature, hardness

CLC Number:

TG156

Li Chunhui, Li Xiaoyuan, Yu Wenchao, Wang Maoqiu, Wu Run. Effect of cooling rate on martensitic transformation initiation temperature and hardness of super high strength martensitic steel[J]. Heat Treatment of Metals, 2022, 47(7): 183-189.

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