The Predictive Maintenance of Vacuum Furnaces for Carburising Processes

Low-pressure carburising processes are an important element of thermo-chemical treatment in such as the automotive, aviation and/or mechanical engineering industries. The reliability of heat treatment equipment is crucial due to the load placed on them and the possible costs associated with downtime. The value of the damaged charge to be treated, can sometimes exceed the value of the kiln itself. This article presents an analysis of low-pressure carburising processes carried out at a pit furnace with ceramic insulation, with special reference to the accumulation of carbon deposits on heating elements. The accumulation of carbon deposits on heating elements and current feedthroughs can lead to excess voltages and to these heating elements becoming damaged. Based on the research conducted, a procedure for burning out the carbon deposit has been developed, which is an element of the predictive maintenance of equipment for low-pressure heat treatment in carburising processes. Carrying out the procedure is based on data collected by a sensor dedicated to detecting the level of carbon deposits.