Phase transformation of austempered and quench-tempered gray cast irons under laser surface hardening treatment

ABSTRACT

In this research, the effects of laser surface hardening treatment on the phase transformation of austempered and quench-tempered grey cast irons were investigated. It was found that there were four zones in the matrix of austempered grey cast iron and three zones in the matrix of quench-tempered grey cast iron produced by the laser hardening process. Both cast irons had central laser-hardened zones containing ledeburite (Zone 1) and heat-affected zones (Zone 2) containing martensite. For austempering, an additional heat-affected zone (Zone 3) consisting of tempered ausferrite and a substrate (Zone 4) consisting of ausferrite was formed in the matrix, the dimensions of the laser-hardened and heat-affected regions were independent of the austempering and tempering temperatures. The results reported in this work could be used as a valuable reference for future research on laser-hardened grey cast iron applications. For quench tempering, the substrate (Zone 4) consisted of tempered martensite. Additionally

KEYWORDS:

• Gray Cast Iron
• austempering
• quench-Tempering
• laser Surface Hardening

Acknowledgements

This work was supported by the High Academic and Research Development Program at Zhejiang Sci-Tech University [Grant 19022140-Y]; [Grant 11130131741904] and [Grant 11130231711923], and the Automotive Tribology Center, Oakland University, MI, USA

Declaration of Interest Statement

The authors declare that there is no conflict of interest regarding the publication of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.