Ion carburizing

Abstract From the Canadian patent

A control process for carburizing the case of a ferrous workpiece by means of the ion "glow discharge" technique is disclosed. Uncontrolled arcing is prevented during gas changeover after sputter cleaning the workpiece by reducing the power of the DC pulsed current while introducing a substantially pure, carbon bearing gas into the work chamber and, prior to changeover completion, increasing the power to a predetermined watt density. Optimum processing time and case uniformity is achieved by setting the watt density power at a predetermined value correlated to the carburizing temperature and setting the carbon bearing gas flow rate at a constant mass flow rate correlated to case carbon …