Controlling the nucleation of multiple precipitates in precipitation-strengthened steel through Mo partitioning

Abstract

In this study, atom probe tomography and first-principles calculations were used to investigate the influence of Mo addition on multiple precipitates, including isolated NiAl-based precipitates as well as NiAl-based and Cu-rich co-precipitates, in high-strength ferritic steel. The co-NiAl-based precipitates were experimentally confirmed to be nucleated from the abundance of Cu atoms. The addition of Mo accelerated the nucleation process of Cu-rich precipitates and structural transformation of co-precipitates, led to a considerable increase in the nucleation rate of NiAl-based precipitates, and slightly promoted isolated NiAl-based precipitates. The results were discussed from the perspective of lattice misfits and mixing enthalpy.

KEYWORDS:

• Nanoparticles
• Mo addition
• Precipitation-strengthened steel
• Atom probe tomography
• First-principles calculation

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Nos. U1860103, 52101025), the Fundamental Research Funds for the Central Universities (No. N2209003), Key Research and Development Program of lvliang (No. 219114) and Doctoral Scientific Research Foundation of Liaoning Province (No. 2019-BS-254). The first-principles calculations were supported by Advanced Computing East China Sub-center and LvLiang Cloud Computing Center of TianHe-2 of China. The authors are grateful for the APT analysis from Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, China.

Disclosure statement

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

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number U1860103] and the Fundamental Research Funds for the Central Universities (No. N2209003).