Effect of quenching medium on short-range order in Fe-rich Fe-Cr alloys

TL;DR

This study investigates how different quenching media affect short-range atomic order in Fe-Cr alloys, revealing that none produce a completely random distribution, with brass quenching maintaining the highest randomness.

Contribution

It provides a comparative analysis of quenching media on atomic ordering in Fe-Cr alloys using Moessbauer spectroscopy, highlighting the influence of quenching methods on atomic distribution.

Findings

Brass quenching results in the highest atomic randomness.

Water and nitrogen quenching cause surface oxidation and chromium depletion.

None of the media produce a fully random atomic distribution.

Abstract

Effect of a quenching medium (water, liquid nitrogen and block of brass) on a short-range ordering in Fe(100-x)Cr(x) (x less than 19) alloys was studied with the Moessbauer spectroscopy. The distribution of Cr atoms was expressed in terms of the Cowley-Warren short-range order (SRO) parameters: alpha1 for the first neighbor-shell, alpha2 for the second neighbor-shell and alpha12 for both neighbor-shells. It was revealed that none of the quenching media resulted in a random distribution of atoms, yet the degree of randomness was the highest for the samples quenched onto the block of brass. The quenching into water and liquid nitrogen caused a partial oxidation of samples surface accompanied by a chromium depletion of the bulk. Quantitative analysis of various phases in the studied samples both in their bulk as well as in pre surface zones was carried out.