ROLLER HEARTH FURNACE AND PROCESS OF MANUFACTURE OF HEAT TREATMENT PRODUCT BY ROLLER HEARTH FURNACE

摘要

PROBLEM TO BE SOLVED: To provide a roller hearth furnace in which a reduced thickness of a transportation roller formed by carbon is hardly produced.SOLUTION: A roller hearth furnace of this invention comprises side walls for defining a heating chamber for heating a workpiece in atmosphere of inert gas or reduction gas against outside; roller insertion holes arranged to pass through the side walls; a transportation roller in which a part for transporting the workpiece in the heating chamber is formed by carbon, a shaft end part passes through the roller insertion hole of the side wall and protruded outside the heating chamber; a purge cover attached to an outer surface of the side walls to cover and tight-seal a shaft end part of the transportation roller; a gas supply part for supplying inert gas or reduction gas into the purge cover from outside part; and a gas-feeding-in passage for feeding inert gas or reduction gas in the purge cover into the heating chamber.SELECTED DRAWING: Figure 3