Effect of element segregation on deformation mechanisms of nano/ultrafine-grained 304 stainless steel

Abstract

The effect of Cr and Ni element segregation on austenite stability and deformation mechanisms of nano/ultrafine-grained 304 stainless steel obtained by cryogenic rolling plus annealing treatment was systematically studied. The results showed that the nano/ultrafine-grained steel had a good combination of strength and ductility (yield strength ∼896 MPa, tensile strength ∼977 MPa, and elongation ∼39.6%). According to the findings, the formation of Cr segregation in the body-centered cubic structure at the intersection of austenite grain boundaries and localised austenite grains with low Ni content reduced the austenite stability of the nano/ultrafine-grained steel and promoted the generation of strain-induced martensite during plastic deformation, resulting in the deformation mechanism dominated by the transformation-induced plasticity effect.

KEYWORDS:

• 304 Stainless steel
• Nano/ultrafine grains
• Grain boundary segregation
• Austenite stability
• Strain-induced martensite

Acknowledgements

This study was funded by the Fundamental Research Funds for the Central Universities [Grant No. N2107013]. The equipment support of the State Key Laboratory of Rolling and Automation is also gratefully acknowledged.

Data availability

The raw data required to reproduce these findings are available from the corresponding author on reasonable request.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Fundamental Research Funds for the Central Universities [N2107013].