Surface Analysis of Prealloyed with Manganese Steel Powder

Paper in proceeding, 2009

Surface chemical composition of water atomized steel powders prealloyed with manganese, was investigated with regard to composition, morphology, size and distribution of surface oxides. The oxides formed on the powder surface were studied by means of surface analytical techniques (XPS, SEM and EDX). Dependence of surface products composition on the manganese content was clearly established. Powder particles are covered by heterogeneous oxide composed of particulate features of stable oxides (Cr-Mn-Si) and homogeneous iron surface oxide layer in between. Manganese content increasing from 0.3 to 1.8 wt.% results in moderate decrease in iron oxide layer thickness that is in the range 6-7 nm. Linear dependence of portion of cations of high oxygen affinity elements (manganese and chromium) in the surface oxide with increasing alloying content was registered. Results indicate that quality of the manganese pre-alloyed powder from the surface composition point of view is comparable with industrial Cr- or Mo-alloyed grades.