Heat Treatment Defects on Camshaft Lobes

THE PROBLEM

The production of defect-free engine components is critical to any vehicle manufacturer and supplier. Even in the most highly controlled production processes, things happen: tools break, motors stop, and heat treat processes fail.  It is obvious when tools and motors are damaged, but it is not so obvious when the heat-treating process is malfunctioning.  This typically requires specialized inspection.  

In this case, the customer discovered soft spots on cam lobes due to a break down in the cleaning system and parts were being heat treated with debris on the surface. The manufacturer was initially only able to detect these defects using nital etch and were in search of a non-destructive method in order to reduce scrap costs.