Abstract
In order to produce low oxygen powders containing Cr, Mn and Si for hot formed P/M steel, a reduction of surface oxides by prealloyed carbon has been investigated. Gas analysis data showed that the reduction of the alloy steel powders was accomplished in two stages, the first was mainly the reduction of iron oxides by carbon at about 700°C, and the second was mainly that of oxides of alloyed elements over 1000°C. The process analysis studies indicated that the rate determining process of C-O reaction in powders was chemical reaction at the interface of metal and oxide layer at the initial step, and diffusion of carbon in particles at the later step.
