Effect of Mn on precipitation behaviour of NiAl phase in Fe–NiAl steels

ABSTRACT

The microstructural evolution of two model alloys, Fe–NiAl and Fe–NiAl–Mn, during aging at 500°C was investigated using atom probe tomography (APT). Vickers micro hardness measurements showed that the addition of Mn increased the hardness and decreased the time to reach the peak hardness. Both alloys exhibited a softening process at the initial stage of aging. The APT results showed that adding Mn increased the number density of NiAl nanoparticles significantly, and Mn atoms partitioned into the NiAl nanoparticles, occupying the Al sites preferentially. The precipitation of NiAl nanoparticles was accelerated by the addition of Mn because Mn increased the nucleation driving force for NiAl precipitates and reduced the strain energy for the nucleation.

KEYWORDS:

• Mn
• NiAl nanoparticles
• precipitation
• atom probe tomography

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

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by National Key Research and Development Program of China [No.2017YFB0703002, 2016YFB0700401 and the State Key Laboratory of Rolling and Automation of Northeastern University Development Fund [No.2016002]].