| 摘要 |
PROBLEM TO BE SOLVED: To reduce the change frequency of the rolls at the time of skin pass rolling, and to improve productivity by forming the thermal spraying coating of wc-Co based thermet on the peripheral surface of the rolls, and giving wear resistance to them. SOLUTION: A thermal spraying machine 13 is used. By a high speed flame thermal spraying method burning liquid fuel with high pressure air or high pressure air with oxygen content increased, a thermal spraying coating 12 in which hard grains are scattered in metallic binder, is formed on the peripheral surface 11a of a roll base material 11, and a skin pass rolling roll 10 is obtained. At that time, the thickness of the thermal spraying coating 12 to be formed must be 20 to 40μm, and the thermal spraying coating 12 must consist of 75 to 90% hard grain, based on weight, and the remainder which is the metallic binder. In addition, this hard grain must be (wc), or its main component must be (wc) and it must contain carbide other than the (wc) and/or boride exceeding 0 and 30wt.% or below. And, the metallic binder must consist of one kind of Co, Ni and Cr or two kinds of them or over. |
