| 摘要 |
A scale preventing device according to the present invention includes a low-oxidation member which forms a low-oxidizing atmosphere by injecting inactive gas to the leading part of a rolling mill system in which a plurality of rolling mills is successively arranged; and a speed control member which increases the rotation speed of a rolling roll on the lead portion in order to increase the progressing speed of a material on the lead portion in comparison with that on the rear portion of the rolling mill system. The scale preventing method according to another aspect of the present invention includes a low-oxidizing atmosphere forming step of forming a low-oxidizing atmosphere by injecting the inactive gas to the material progressing from the lead portion of the rolling mill system in which the rolling mills are successively arranged; and a material progressing speed increasing step of increasing the progressing speed of the material in comparison with that on the lead portion. The low-oxidizing atmosphere forming step and the material progressing control step are performed on the lead portion at the same time. The present invention forms the low-oxidizing atmosphere on the lead portion of the rolling mill system in the early rolling stage and reduces contact time of the material with oxygen by increasing the progressing speed of the material, thereby preventing the diffusion of a scale layer on the surface of the material in the early rolling stage. Therefore, the present invention prevents a decrease in the quality of the material after rolling as scale blisters are rarely generated on the surface of the material even though oxidation time is increased in the hot-rolling process. |
