Thermal measurements for service life estimations of high power induction hardening coils

The temperature profile of an induction coil is an important factor in the estimation of induction coil service life. Coil surface temperatures are measured in an improved experimental setup by a thermographic camera. Temperatures are measured on three cross sections commonly used in induction heating coils at varying current levels and varying coolant flow rates. The measurements are compared with previous measurements and to a numerical model. In general good agreement is found between measurement and model, but important differences were found. These differences are discussed.