Evaluation of Chill Contents in Flake Graphite Cast Irons Using AC Magnetization Method

In this study, feasibility of evaluation for chill contents in flake graphite cast iron is investigated based on AC magnetization method, which is one of the electromagnetic nondestructive evaluation methods. Magnetic properties of flake graphite cast iron samples with different chill contents were measured by a B-H loop analyzer in order to discuss their relation to chill contents. It was found that some magnetic parameters of the flake graphite cast iron depend on the contents of matrices and graphite. Especially, the hardness, which reflects chill contents, has good correlation with the area of hysteresis loop at relatively high frequencies. Focusing on the finding, AC magnetization method was applied to evaluation for the chill contents. Through the experiment, it was found that there is a correlation between hardness of flake graphite cast irons with chill and signals. In consequence, AC magnetization method has a capability of evaluating chill contents in flake graphite cast irons.