| 摘要 |
PURPOSE:To improve the abrasion resistance and reduce the degradation in surface accuracy with an increase in the times of use by constituting a roll for cooling of molten metal with a high-speed steel or superhard alloy and forming a carbide coating layer on the circumferential surface thereof. CONSTITUTION:In a roll for cooling and solidifying the molten metal ejecting from a nozzle by allowing the same to contact on the circumferential surface thereof, a high-speed steel or superhard alloy which does not cause degradation in its hardness despite the rise in surface temp. and the hardness of which itself is high is used for the roll body. Next, a carbide coating layer having hardness about 3 times higher than that of a nitride coating layer is formed as the coating layer. These yield the roll which is much superior to that when a nitride coating layer is used. Here, the suitable thickness of the carbide nitride layer is about 5- about 100mum. |
