Formation of chromium nitride layers on AISI 1010 steel by nitro-chromizing treatment

Abstract

In this study, chromium nitride coating was realized on AISI 1010 steels by nitro-chromizing treatment. Steel samples were tufftrided at 575 degrees C for 2 h in the first step of the coating process, and then chromized by pack method in the powder mixture consisting of fierro-chromium, ammonium chloride and alumina at 1000 degrees C for 1-4h. Samples were characterized by scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy, X-ray diffraction (XRD) analysis and Vickers micro-hardness tests. Coating layer formed on the steel samples is smooth and compact and well bonded to the steel matrix. The thickness of chromium nitride layer formed on the steel samples ranged from 5.16 +/- 1.48 to 13.45 +/- 1.73 mu m, depending on the treatment time. The average micro-hardness value of the layer was 1789 +/- 59 HV0.05. The layer consisted of Cr2N and (Cr,Fe)(2)N(1-x) phases, according to XRD. EDS results showed that coating layer includes chromium and nitrogen. (c) 2006 Elsevier Ltd. All rights reserved.