| 摘要 |
PURPOSE:To remove the films consisting of the salt bath composition stuck on surfaces through simple operation by pulling a steel wire rod which is immersed in a heated and molten salt bath and is thereby heat treated, out from the bath inside and bringing the same immediately into contact with water. CONSTITUTION:A wire rod 2 to be heat treated which is coiled on a swift 1 is delivered in an arrow direction by a guide roll 2 and is introduced into a heat treatment furnace 4. A salt bath 6 heated and melted with a heater 5 is formed in the furnace 4, and the wire rod 2 introduced into the bath 6 is wound plural times on a rotary drum 7 and is immersed therein, whereby it is heat treated. The wire rod 2 is pulled out from the bath 6 is guided by a guide roll 2 and is introduced immediately into a water tank 13. At this time, the temp. difference between the steel wire rod pulled out from the bath 6 and the water temp. to be brought in contact therewith is set at above 100 deg.C. |
