Effect of hydrogen composition on reduction of iron powder

In a certain content of H2 atmosphere at high temperature in the reduction potential (make) in the direction of the reduction reaction, but in the process of cooling is becoming oxidizing atmosphere, can make instead have reduction of iron powder to oxidation In 800, for example, with nearly 30% of water vapor H2 atmosphere can make the FeO reduction for Fe, but such as cooling to 150, the same of H2 atmosphere makes have reduction of iron powder to oxidation;Therefore, in the process of secondary reduction, to control the content of water vapor in hydrogen, it is necessary to make the content of water vapor in hydrogen atmosphere less than 5% of its equilibrium gas phase composition, so as to avoid the oxidation of reduced iron powder in the later stage of reduction as much as possible, affecting the quality of the final reduced iron powder.