Formation of multi-component boronization by adding transition metal group VIB

Multi-component boron coatings of boron and transition metal group VIB (Cr, Mo, W) were studied on low carbon steel AISI 1018 by using simultaneous powder pack method of boronizing and metalizing at 950 degrees C. The coating morphology was observed and the coating thickness was measured. The microhardness across the depth of coating was also investigated. XRD phase identification revealed forming of Fe2B, Cr2B, and CrB on two-component diffusion of B-Cr; Fe2B and MoB on two-component diffusion of B-Mo, and Fe2B, FeB, W2B, and Fe7W6 on two-component diffusion of B-W. XRD quantitative phase analysis was determined by using Rietveld Refinement. Moreover, Synchrotron Microfluorescence was used to identify the element distribution. Finally, the mechanism of formation of multi-component boronizing by adding transition metal group VIB was purposed responding to the coating formation and atomic size of the transition metals. (C) 2012 Elsevier Masson SAS. All rights reserved.