CHILLING TENDENCY EVALUATING METHOD FOR MOLTEN METAL AND SUBSTANTIALLY UNCHILLED CAST IRON USING CHILLING TENDENCY EVALUATING METHOD FOR MOLTEN METAL

摘要

PROBLEM TO BE SOLVED: To provide a more precise and highly accurate molten metal chilling tendency evaluating method which is indispensable for developing and manufacturing hardly chilling molten metal and can also be used for quality control of various molten metals and by which a parameter capable of expressing a stricter chill generating critical value can be examined from cooling speed of the molten metal, and a cast iron manufacturing method using this evaluating method. SOLUTION: A molten metal cooling curve by variously changing cooling speed is analyzed, and maximum cooling speed after coagulation is found on respective molten metals, and its found temperatures are compared with each other, and the highest temperature among them is set as an application temperature, and maximum cooling speed of the other molten metal is recalculated at the application temperature, and is compared and evaluated, and critical cooling speed of chill crystalization is strictly found. Substantially unchilled cast iron is also produced by molten metal whose property is more optimally adjusted by a cast iron manufacturing method using a chilling tendency evaluating method of the molten metal.