COOLING METHOD FOR REINFORCING HARDNESS AND SOLVING TARNISH PROBLEM USING NITROGEN GAS IN HEAT TREATMENT PROCESS

摘要

PURPOSE: A cooling method for reinforcing hardness and solving tarnish problems using nitrogen gas in the heat treatment process is provided to increase quality and productivity of an iron processed goods by cooling the iron processed goods in a cooled reactor after feeding nitrogen into a cooled reactor so that hardness and color can be accurately adjusted to the established standards and a consumed time of the cooling operation can be shortened. CONSTITUTION: A plurality of nitrogen gas injection pipes(3) are mounted on a wall surface(2) of cooling chamber body(1). The plurality of nitrogen gas injection pipes(3) are connected to a nitrogen tank(4) through a connecting pipe(5). A recovering pipe(10) is installed on top of the cooling chamber body(1). The recovering pipe(10) is connected to the connecting pipe(5) through a cooler(11) and a blower(12). A carburized iron processed goods is charged into the cooling chamber and cooled by feeding nitrogen and flowing it around.