| 摘要 |
459,328. Rolling. DEHN, F. B., 103, Kingsway, London.-(American Rolling Mill Co. ; 703, Curtis Avenue, Middletown, Ohio, U.S.A.) Jan. 10, 1936, No. 941. [Classes 83 (ii) and 83 (iv)] [See also Group XXIII] Making rolls.-Rolls for roughening sheets especially for vitreous enamelling are made by removing the outer chilled surface 2 of a cast iron roll leaving exposed the inner dendrite zone 3 which comprises a surface of mixed hard particles of cementite and softer parts of graphite, carbon, and grey iron, which is treated so that the harder parts stand up in sharp edged relief. Rolls which have had the outer chill worn away may be used, or new rolls may be ground together with, e.g. open hearth flue dust and water to remove the outer chilled surface. To bring the harder parts into relief, the roll may then be treated with acid, or when the relief has been worn off it may be renewed by idling under a water film, so that they grind each other. Alternatively, rolls with a chilled surface may be heat treated to modify the surface carbon content and then developing a roughened surface as above. Fig. 2 shows the magnified surface of a sheet formed as above. |
