PURPOSE: To produce a hearth roller for heat treatment furnace excellent in homogeneity, high hardness, and oxidation resistance by constituting the part, to be in contact with a steel sheet, of a hearth roller by the use of glassy carbon prepared by subjecting thermosetting resin to carbonization by baking, having specific porosity, and free from crystallite.
CONSTITUTION: A catalyst (p-toluenesulfonic acid, etc.) is added to a thermosetting resin (furan resin, phenolic resin, etc.), which is subjected to defoaming treatment, molded, and hardened. Subsequently, the resulting hardened body is carbonized by baking in an inert atmosphere, preferably at ≥ about 1000°C, by which glassy carbon in which porosity is regulated to 0.02-0.20% and no crystallite is detected by means of X-ray diffraction is prepared. Then, at least the part, to be brought into contact with a steel sheet, of a hearth roller is constituted of the above glassy carbon. By this method, the hearth roller having low porosity and superior picking-up resistance can be obtained.
TANADA YOSHINOBU
KASAHARA MASATOSHI
MATSUO HIDEYASU
ITO KAZUO
