Realising carbide ultrafast homogenisation under pulsed electric current

Abstract

Network carbides, as a deleterious precipitate to the mechanical properties of bearing steel, are difficult to eliminate by traditional heat treatment. Here, an innovative strategy to rapidly dissolve network carbides using electric current pulses to improve the uniformity of the microstructure is proposed. The results show that the diffusion driven by electromigration is significantly enhanced compared to traditional heat treatment due to the high-density current on the network carbide surface. Furthermore, grain boundaries as fast diffusion paths play a key role in accelerating the dissolution of network carbides.

KEYWORDS:

• Network carbides
• pulsed electric current
• electromigration
• electrical free energy
• carbon atom diffusion

Acknowledgements

The work was financially supported by National Natural Science Foundation of China (U21B2082; 51874023; U1860206), the National Key Research and Development Program of China (2019YFC1908403), Fundamental Research Funds for the Central Universities (FRF-TP-20-04B) and Recruitment Program of Global Experts.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Fundamental Research Funds for the Central Universities: [Grant Number FRF-TP-20-04B]; National Key Research and Development Program of China: [Grant Number 2019YFC1908403]; National Natural Science Foundation of China: [Grant Number 51874023]; National Natural Science Foundation of China: [Grant Number U21B2082]; National Natural Science Foundation of China: [Grant Number U1860206]; Recruitment Program of Global Experts.