2019 Volume 59 Issue 3 Pages 551-558
Induction heating (IH) is commonly used for heating and heat treatment. An accurate prediction of temperature distribution is required to optimize the heating parameters, such as the heating coil dimensions, coil current, and heating time, without trial and error. In this study, temperature-dependent B-H curves and changes in phase transformation under rapid heating were measured and used for IH analysis to improve the prediction accuracy. IH experiments were also carried out to confirm the accuracy of the analysis. Consideration of the temperature-dependent B-H curves improved the prediction accuracy up to the Curie temperature, and consideration of changes in phase transformation temperature under rapid heating improved the accuracy for temperatures above the Ac1 temperature. The maximum error between the experimental and calculation results for a columnar test piece was approximately 25 K, when the experimental temperature was 1300 K. This error is 9 times smaller than that obtained with a conventional analysis method. Good agreement was also obtained between the experimental and calculated values for a test piece with a convex projection, for which the temperature distribution and evolution are complex.