Abstract: Effect of heat treatment process parameters on the mechanical properties and nitriding hardening properties of 20Cr3MnMoV steel was investigated. The results show that the heat treatment of the 20Cr3MnMoV steel is composed of solid solution treatment, aging, preaging and nitriding. Reasonable controlling the aging process is the main technological characteristics of the heat treatment of the 20Cr3MnMoV steel. By using respectively solid solution treatment+ full aging, nitriding without preaging, and preaging+ nitriding, it can be adapted for dies and components at different working conditions, so that it satisfies the different requirements of wear resistance and strength-ductility. Nitrocarburizing of 20Cr3MnMoV steel can be used to realize fast nitriding, deep layer nitriding-hardening, and matrix hardening, which has wide-spread prospects of application.

Key words: 20Cr3MnMoV steel, age-hardening, nitriding-hardening, aging, preaging