Heat treatment process optimization for 4Cr5Mo2VCo steel

doi:10.13251/j.issn.0254-6051.2022.04.021

Abstract

Abstract: Hardness and impact property of 4Cr5Mo2VCo steel treated by different processes were measured, and the microstructure and fracture morphology were analyzed by SEM. The results show that in the quenching temperature range of 1000-1100 ℃, the hardness of the 4Cr5Mo2VCo steel first increases and then decreases, up to 59.2 HRC. The number of undissolved carbides decreases with the increase of quenching temperature, and almost all of the carbides dissolve into the matrix at 1100 ℃. During tempering, the secondary hardening peak temperature of the 4Cr5Mo2VCo steel is 520 ℃, and the hardness decreases subsequently with the increase of tempering temperature. The impact absorbed energy of the specimens quenched at different temperatures increases firstly and then decreases gradually with the increase of tempering temperature. In the hardness ranger of 44-46 HRC, the optimum heat treatment process of the 4Cr5Mo2VCo steel is quenching at 1060 ℃ for 30 min and tempering twice at 600-610 ℃ for 2 h, under which, the average impact absorbed energy can reach 410 J.

Key words: 4Cr5Mo2VCo steel, heat treatment, microstructure, hardness, impact property

CLC Number:

TG142.1

Li Li, Zeng Yan, Wu Xiaochun. Heat treatment process optimization for 4Cr5Mo2VCo steel[J]. Heat Treatment of Metals, 2022, 47(4): 133-140.

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