METHOD OF JUDGING GRAPHITE SPHEROIDIZATION ABILITY OF MOLTEN METAL OF SPHEROIDAL GRAPHITE CAST IRON

摘要

PURPOSE:To enable the graphite spheroidization ability of molten metal of spheroidal graphite cast ion rapidly and surely in fundry by rupturing the sample of the specific dimensions having been cast in molds, grindling only the minute portion of the fracture surface and observing the ground surface with a metal reflecting microscope. CONSTITUTION:The molten metal immediate after spheroidization treatment is cast in a mold 21 which has a cavity 22 of 15 to 25 mm in diameter and about 100 mm in depth. The test blank having been drawn out after the molten metal has solidified is hammered at its approximate central part and is thereby ruptured. One of these is held and fixed in a sample fixing device 2 which is mounted on the working table 9 of a stanchion 10. Next, an abrasive material 3 is fixed to a chuck 4 and rotating power is applied to a revolving shaft 5 by way of a motor 8 and reducer 9. Thereafter, the abrasive material 3 is lowered by turning a revolving shaft elevating handle 6 and is pressed to the sample 1, by which the minute portion of the sample 1 is concentrically ground. The sample 1 is then removed from the chuck 4 and its ground surface is observed with a metal reflecting microscope.