ON THE CARBON-RESTORATION OF STEELS(II)

Cementation by the modified Town Gas

Abstract

The various decarburized layers resulted from different decarburizing treatments were carburized in the modified town gas, and following results were obtained:
(1) The carburizing power of the modified gas containing CO 20%, CH₄ 5%, H₂ 54% and N₂ 20%, was weaker than that of charcoal+BaCO₃ 20%. In the carbon restoration by the modified gas as well as by the common solid carburizer, both depth and amount of carburization were larger in specimens of non-oxidizing decarburization than those in specimens of oxidizing decarburization.
(2) In the carbon restoration by the modified gas, the carburization was not accompanied with the oxidation as in the case of the common solid carburizer.
(3) In the carbon restoration by the modified gas, both depth and amount carburization in specimens of oxidizing decarburization approached to those of non-oxidizing decarburization specimens with the increase of the carburizing time. It was presumably explained by the fact that carburization of the decarburized layer formed by the oxidizing decarburization was accompanied. by reduction of the oxygen in the decarburized layer and the diffusion of carbon through these layers becomes easier.