To provide a method for evaluating metal cleanliness which is excellent in speed and reliability.
Using a melting device wherein a high frequency induction heating coil 4 is provided around the outer periphery of a cylindrical side wall 2 in vertical direction, a pillar-like metal specimen 6 is so inserted from a sample insert hole 5 at a lower end of the side wall that its top part reaches the level of the high frequency induction heating coil, the top part of the specimen 6 is melted in inactive gas atmosphere, then it is coagulated and taken out of a melting furnace, and a non-metal inclusion 7 discharged and accumulated on the coagulated surface is measured. A fluorescent X-ray spectroscopy using an energy-diffusion type spectroscope is preferred to be used for measuring a non-metal inclusion. The coagulated surface is melted or allows electrolysis to melt it, and a solution containing a non-metal inclusion as residue is filtered, for weighing according to grain size or for analysis.
TAKEUCHI EIICHI
HASEGAWA HAJIME
