Effect of Mo on thermal stability of 4Cr5Mo2V hot-work die steel

doi:10.13251/j.issn.0254-6051.2022.12.029

Abstract

Abstract: Effect of Mo on the thermal stability of 4Cr5Mo2V hot-work die steel was investigated, and the microstructure evolution was characterized by means of scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the difference of thermal stability between the tested steels containing 1.9%Mo and 2.4%Mo at 600 ℃ is small. After holding at 650 ℃ for 48 h, the hardness of the 1.9%Mo steel is lower by 2.3 HRC than that of the 2.4%Mo steel, the recovery in the martensite matrix is more obvious, and there are more Cr-rich large-sized spherical M₂₃C₆ carbides with the size between 150-200 nm. While in the 2.4%Mo steel, more fine M₂C type secondary carbides are precipitated which hinder the Cr-rich carbides growth, the average particle size of carbides is smaller, so that the 2.4% Mo steel has better thermal stability.

Key words: hot-work die steel, thermal stability, carbides, Mo element

CLC Number:

TG142.45

Shen Yutao, Zuo Pengpeng, Wu Xiaochun. Effect of Mo on thermal stability of 4Cr5Mo2V hot-work die steel[J]. Heat Treatment of Metals, 2022, 47(12): 168-174.

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