On the grain boundary chemistry of chromium containing martensitic steels

Abstract

Auger electron spectroscopy and segregation isotherms have been used to study the grain boundary chemistry with respect to the solute and the trace elements in a low chromium and a high-chromium martensitic steel with emphasis on the effects of the chromium content. It is observed that the presence of high chromium concentration in the steel does not influence the cooperative (Cr---N) interaction process and the segregation behaviour of S and Sn. It, however, increases the grain boundary phosphorus concentration and decreases carbon concentration, a behaviour which is shown to be more an outcome of the site-competitive (C---P) process than a consequence of the strong cooperative (Cr---P) interaction process.