Evolution of carbides and performance of knives made of aged 8Cr13MoV steel

Abstract

The dissolution and precipitation behaviours of M₇C₃ and M₂₃C₆ carbides in 8Cr13MoV steel were calculated using Thermo-Calc software. The mechanical properties of carbides were calculated using the Vienna Ab-initio Simulation Package. Results showed that M₇C₃ carbides were ductile and M₂₃C₆ carbides were brittle. High holding temperature provided favourable conditions for M₇C₃ carbides to precipitate and promoted the dissolution of bulky M₂₃C₆ carbides. Two heat treatment sequences were designed. During aging treatment, dispersive rodlike nanoscale M₇C₃ carbides precipitated from matrix, which improved wear resistance and the retention ability of the cutting edge of knives by 56 and 22%, respectively.

KEYWORDS:

• Carbides
• mechanical properties
• aging
• precipitation
• sharpness

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 51574025; 51504019] and Guangdong YangFan Innovative & Entepreneurial Research Team Program [grant number 2016YT03C071].