Measurement and analysis of continuous cooling transformation curves for 42CrMo steel

doi:10.13251/j.issn.0254-6051.2020.09.044

Abstract

Abstract: Microstructure transformation and bainite content at different cooling rates were analyzed to obtain the CCT curves of 42CrMo steel by using JMat-Pro software to simulate the continuous cooling transformation curve and by using DIL805L thermal dilatometer to determine the phases transformation temperatures.The results show that Ac₁ and Ac₃ of the 42CrMo steel are 743 ℃ and 792 ℃,respectively.When the cooling rates are less than 0.5 ℃/s,the transformation products are proeutectoid ferrite and pearlite.In the cooling rate range of 0.5-10 ℃/s,a certain amount of bainite appears which increases first and then decreases with the cooling rate increasing,meanwhile the martensite content increases gradualy and resulting to a large increase of hardness.When the cooling rate is over 10 ℃/s,the resulted microstructure is the mixed collective composed of martensite matrix and a small amount of bainite.

Key words: 42CrMo steel, CCT curves, cooling rate, bainite, JMat-Pro software

CLC Number:

TG113.25

Li Kai, Hu Jianwen, Shi Shaokun. Measurement and analysis of continuous cooling transformation curves for 42CrMo steel[J]. Heat Treatment of Metals, 2020, 45(9): 237-239.

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