873 KにおけるCO-H₂系ガスによる鉄表面上の炭素析出

抄録

The carbon deposition on iron has been studied by means of metallography and thermogravimetry, in order to investigate the carbon depositing behavior and the rate-determining step of the reacion. Two types of carbon, laminar carbon and filamentous carbon, are observed to deposit on iron. The deposition of laminar carbon is predominant through the reaction to form a thick lamina on the entire surface of iron. Filamentous carbon does not deposit on iron but on laminar carbon, and the amount of the deposit is much less than that of laminar carbon. X-ray diffraction shows that iron and cementite are included in laminar carbon. This may be caused by the fact that the iron substrate is attacked by formation and decomposition of cementite on the surface and at the grain boundaries during carbon deposition and that iron and cementite are spalled away into the deposit.
The deposition rate of laminar carbon is controlled by the following reactions on substrate-carbon interface according to gas composition;
(This article is not displayable. Please see full text pdf.)
\ oindentand in the intermediate range both these reactions, where O^∗ is an adsorbed oxygen atom.