A NOTE ON COATING OF SURFACE DIFFUSIONINFILTRATION OF RE ON STEEL 20 AND ARMCO IRON BY CHEMICAL PROCESS

The segregation of the impurities, e. g. S, P, along grain boundaries of as-cast structure and of austenite in the high speed steels as well as the cleaning action of RE elements have been studied by AES. It was found that the more S and P the steels contain, the more their segregation occurs. The segregation becomes remarkably improved by the addition of RE elements, and the enrichment of S at grain boundary goes so far as to vanish when the RE added up to 0.05-0.08%. Some discussion on the segregation and the cleaning action have been also made.