The effect of nickel on the carbide precipitation behavior in Cr–Mo–V hot-working die steel

Release time:2024-11-22 Hits:

First Author:Wei Gong

Correspondence Author:Jialong Tian,Zhouhua Jiang

Co author:Jianbo Yue,Jun Liao,Yang Yu

Journal:Journal of Materials Research and Technology

Volume:27

DOI number:10.1016/j.jmrt.2023.10.229

Place of Publication:Brazil

Abstract:The addition of small amount of nickel to hot-working die steel has been found to be beneficial for hardenability and toughness. In this paper, the addition of nickel to Cr–Mo–V hot-working die steel was studied to improve hardenability, and the inherent mechanism of enhancing toughness was further explored. The research results indicate that nickel as a non-carbide-forming element does not alter the type and total amount of carbide precipitation at equilibrium, but it can dissolve into the matrix and form substitutional lattice distortions with Fe atoms, promoting the dispersion of secondary carbides during the tempering process. This mechanism can reduce intergranular precipitation and inhibit grain boundary embrittlement, thereby improving toughness. However, it can also accelerate the precipitation, aggregation, and growth of secondary carbides during prolonged tempering, which deteriorates the high-temperature anti-softening properties of die steels. The role of Ni has been revealed through thermodynamic and kinetic calculations. The results show that Ni significantly enhances the diffusion coefficient of Cr atoms in the face centered cubic (fcc) Fe matrix during tempering and also improves the phase transition driving force of various precipitates. This work provides new insights into the mechanism of Ni in hot-working die steels, and can provide guidance for designing novel hot-working die steel.

Funded by:企业横向课题

Key Words:Hot-working die steel, Ni element, Anti-softening property, Impact toughness, Thermodynamic and kinetic calculations

Indexed by:SCI JCR Q1

Discipline:Engineering

Document Type:JCR 一区

First-Level Discipline:Metallurgical Engineering

Page Number:4452–4460

ISSN No.:2238-7854

Translation or Not:no