Gaseous decarburization of white cast irons

Decarburization of two white cast irons, differing only in microstructure, has been studied using a 20% carbon dioxide-80% carbon monoxide atmosphere. Carbon loss and depth of decarburization at 1000°C and 1050°C were measured as a function of time. A mathematical analysis of decarburization is developed and from a comparison of this with the experimental results it is concluded that the diffusion of carbon in austenite is the rate controlling process.