| 摘要 |
PURPOSE:To prevent the partial wear of a contact face and the adhesion of the wear powder and to improve the life and quality of a guide roller by forming the contact face with the rolling stock at least of the guide roller for the rolling mill rolling a round bar and wire rod by the silicon nitride ceramics limiting a porosity and face roughness. CONSTITUTION:A pair of guide rollers G are formed by the dense silicon nitride ceramics having <=1% porosity and the surface roughness of the contact face M with a rolling stock L in taken <=6s. For the silicon nitride ceramics, those which add an yttrium oxide and magnesia or cerium oxide to silicon nitride and SIALON, besides the SIALON which adds an alumina to silicon nitride are used. Besides those which form the whole body of the guide roller G with these silicon nitride ceramics, those which form the outer peripheral face S of the contact face M only with the silicon nitride ceramics will do. |
