| 摘要 |
PURPOSE:To obtain a process roll for iron making machines having excellent wear resistance by limiting the thickness of a film to be formed on the surface of a roll main body and the component compsn. thereof. CONSTITUTION:The component compsn. of the film on the surface of the process roll for iron making machines is composed to contain, by weight, 10 to 25% chromium carbide and 5 to 15% Ni and to consists of the balance one or two kinds of the carbide and boride of tungsten. The wear resistance is not obtd. when the ratio of the chromium carbide is below 10wt.%. Peeling is liable to arise when the ratio exceeds 25wt.%. The Ni is required to be incorporated at least at 5wt.% in order to assure the wear resistance and lubricity. The hardness is degraded and the wear resistance is lowered as well when the ratio exceeds 15wt.%. The thickness of the surface film layer of the roll body is <=200mum and the optimum range thereof is 7 to 200mum. The wear resistance and heat resistance are not obtd. when the thickness is below 7mum. The peeling is liable to arise when the thickness exceeds 200mum. |
