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

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.