Patent ID: 9540721
Date: 2017-01-10
CPC Classifications: C21D,C23C,F27D

Claim:
1. A method of carburizing ferrous metal parts comprising the steps of: (a) providing a furnace for heating the metal parts and a process chamber; (b) purging an air atmosphere from the process chamber and heating said process chamber to a temperature of at least 1100° F.; (c) feeding a fuel gas to the process chamber and a source of air at a constant flow rate to the process chamber; (d) boosting the process chamber by feeding an enriching gas to the process chamber to create a carbon potential of at least 0.5%; (e) cleaning the process chamber by decreasing the flow of enriching gas to the process chamber to create a carbon potential of less than about 0.25%; (f) repeating the boosting step (d) after performing said cleaning step (e); and (g) repeating the cleaning step(e) after performing said repeated boosting step (f).