Carburization of 310 stainless steel exposed at 800-1100℃ in 2%CH_4/H_2 gas mixture

摘要

Carburization of 310 stainless steel has been investigated after cyclic exposures at high temperatures 800-1100℃ in a 2%CH_4/H_2 carburizing gas mixture for 500 h duration. A thermo-dynamic analysis indicates that 1000℃ is an approximate boundary temperature, below which the environment should result in mixed oxidizing/carburizing behavior, while above this temperature reducing/carburizing behavior should occur. The experimental results agree well with the thermodynamic analysis. Below 1000℃, 310SS suffered external Carburization, oxidation, and internal Carburization. In excess of 1000℃, extensive external Carburization occurred and internal Cr-carbides disappeared. Cr segregation is proposed to interpret the effect of temperature on the continuity of an external scale layer and Carburization behavior.