Thermal conductivity and tempering stability of a novel Cr-Mo-V hot stamping die steel

doi:10.13251/j.issn.0254-6051.2023.07.012

Abstract

Abstract: Thermal conductivity and tempering stability of a new Cr-Mo-V alloyed hot stamping die steel (GYCM) were studied and compared with H13 steel by means of laser thermal conductivity instrument, scanning electron microscope and transmission electron microscope. The results show that after austenitizing at 1030 ℃ for 30 min and oil quenching, the hardness of both the GYCM steel double tempered at 600 ℃ for 2 h and the H13 steel double tempered at 580 ℃ for 2 h are about 50 HRC. Under the same test conditions and with the same hardness, the thermal conductivity of GYCM steel and the H13 steel varies with temperature in different trends. With increase of temperature, the thermal conductivity of GYCM steel decreases, while that of the H13 steel increases. The thermal conductivity of GYCM steel is 20.42%-36.63% higher than that of the H13 steel in the temperature range of 100-500 ℃. When tempered at 600 ℃ and 650 ℃, a large number of size-stable nanoscale Mo and V carbides are precipitated from the GYCM steel,the coarsening degree is lower at higher temperature and for longer time, which effectively reduces the softening degree of tempered martensite. Therefore, the GYCM steel has higher tempering stability than the H13 steel.

Key words: novel Cr-Mo-V die steel, tempering stability, thermal conductivity, carbide

CLC Number:

TG142.4

Li Shuang, Wang Zhen, Fu Junwei, Xia Mingmei, Hua Yingli, Zhang Zheng. Thermal conductivity and tempering stability of a novel Cr-Mo-V hot stamping die steel[J]. Heat Treatment of Metals, 2023, 48(7): 66-72.

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