HEAT TREATMENT FURNACE FOR METAL CHUNK, METHOD FOR REPAIRING HEAT TREATMENT FURNACE FOR METAL CHUNK, AND METHOD FOR PRODUCING INFILL FOR HEARTH USED FOR HEAT TREATMENT FURNACE FOR METAL CHUNK

摘要

Provided is a heat treatment furnace for a metal chunk, provided with a hearth structure having a filling layer of granular refractory on the furnace operation surface side, wherein the filling rate of the granular refractory is 65-100 volume %, and the thickness of the filling layer is more than twice the maximum gain size of the granular refractory.