If you want to obtain
seamless tubes with smaller size and better quality, you must use cold rolling, cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill, and the cold-drawn seamless steel tube is rolled in an annular pass formed by a variable-section round hole groove and a stationary tapered head. Cold drawing is usually carried out on a 0.5-10T single-chain or double-chain cold drawing machine. The production process of general seamless steel tubes can be divided into cold drawing and hot rolling. The production process of cold rolling seamless steel tubes is generally more complicated than that of hot rolling.
How to ensure the surface flatness of cold drawn seamless tube?
1. First of all, choose good quality pipe material. If the quality of the pipe material is not good, there are folds in itself, or there are inclusions, serious scratches and cracks on the surface, and there are edges and corners at the grinding place. After drawing, it is easy to fold after stretching , cracks and other defects.
2. Before drawing, the iron oxide scale or other hard dirt on the pipe material should be cleaned. In order to prevent the iron oxide scale or other hard dirt from being pressed into the surface of the steel pipe during the drawing or straightening process, Cause the surface of the steel pipe to be uneven.
3. Keep the working place, tools and lubricants clean to prevent iron oxide scale and dirt from falling on the surface of the steel pipe.
