Traditionally, carburized gears and other components made from steel forgings are manufactured in separate manufacturing operations consisting of forging, cooling, cleaning, machining, carburizing and hardening. Forging and warm forming technology has improved over the past few years. It is now possible to produce near net shaped parts such as gears with the teeth accurately forged to finished or near finished size. Once formed, the parts are cooled and cleaned of scale. The parts are then subjected to an independent carburizing operation followed either by direct hardening or cooling and subsequent reheat hardening operation. These independent operations result in an inefficient use of energy in that many independent operations of heating and cooling occur. Further, the parts are normally heated in furnaces or by induction without protective atmospheres prior to forging or warm forming and then are allowed to air cool. These steps produce scale on the surface which must be removed prior to subsequent machining or carburizing operations which adds cost to the process.
Another problem associate with independent operations is the inefficient use of energy in that many operations require heating, cooling and reheating.
The present invention is directed to overcome one or more of the problems as set forth above.