| 摘要 |
PURPOSE:To prevent the inner suface of a plug mill from the generation of defects in rolling, by using a superalloy provided with fine rugged parts on a part of its surface used for rolling to manufacture a plug of a plug mill in a seamless pipe manufacturing equipment. CONSTITUTION:A plug 2 of a plug mill used in a seamless pipe manufacturing process, is made of a high toughness, high heat-resistant super-alloy such as ''Hastelloy '', and fine uniform rugged part 3 are previously formed on its rolling part 3. As rust is hardly generated on the surface of the plug 2 while the plug 2 is used in high temperature, the generation of seizing while rolling is prevented, and also, the lowering of a service life due to inner surface defects generating in the inner surface of the mill is prevented. |
