Effect of active constituents in the atmosphere on the sintering of chromium-alloyed PM steels

Paper in proceeding, 2016

Sintering of chromium-alloyed PM steels in atmospheres containing hydrogen and carbon monoxide has been studied. Thermogravimetric analysis was performed on PM steel compacts in atmospheres containing the gaseous constituents individually and when present together. Oxidation/reduction and carburization/decarburization of the compacts was evaluated based on thermogravimetric analysis complemented with bulk carbon and oxygen analysis of the samples. The results suggest that hydrogen promotes the reduction of the iron oxide layer covering the powder surface below 650 °C, the effectiveness of which improves with an increase in the concentration of hydrogen in the atmosphere. When hydrogen was additionally present, an enhancement in the reduction and carburization behavior was observed in the case of carbon monoxide containing atmospheres.