毕业论文关键词：无缝钢管；热轧；冷拔；工艺设计
General Instruction
The task of graduation design is to design the production process of small-caliber heavy wall pipe, to install the necessarily assistant equipments. Main products are petroleum cracking tube with finished size of Φ 19*2mm, and product standards is GB/9948-2013.This product have a large market all over the world. Because its hard working environment is high temperature or high pressure and so on, the production has high qualities and its production technical level has limit. It leads to that many middle or small firms are unable to product it. However, BaoSteel is one of the best companies to have mature technology and production capacity, so it has the value to learn. This design is not only to raise the knowledge during university and steady own ability, but also broaden my vision and improve the ability of thinking by myself and solve the problems systematically.
The seamless tube has a broad variety of production, by comparison, the production of seamless tube takes the process of hot rolling + cold drawing. Because this process has many advantages of low cost, produce quickly, large standard and so on. The process is the adoption of the near-end processing methods, which includes forming to produce size in the part of hot rolling and then producing tubes with less times cold drawing. However, comparing the simple and convenient production of cold drawing, the way of this production leads to an increase in the difficulties and in the pressure on the rolling bearing and motor ability. So the design is focused mainly on the part of the hot check parameters.
Hot-roll production equipments in Shanghai BaoSteel are used in the part of hot rolling. perforation equipment takes the latest skew machine in Shanghai BaoSteel —114 punch, with the species puncher roll angle and crushed rolling forward angle. Tapered roller diameter along the direction of perforation exports gradually increases, which causes high efficiency of puncher piercing and Improves metal deformation and kinematic conditions. It also can roll out the capillary with internal fewer defects, surface quality and concentricity thickness uniformity, lead to less consumption of tools , and can achieve great extension and the expanding volume of perforation. Pipe Mill use Diesher mill for capillary extension, which rolls capillary tube with long mandrel. The mill similar to the two roller rotary piercing mill with godet. As with long production mandrel, it has accurate dimensional, smooth wall, with no abrasions and a certain speed (less than capillary rolling speed), which reduces mandrel consumptions. Aside from two foremost equipments, the production also takes stretch reducing mill. Stretch reducing mill takes micro stretch reducing mil. It has 12 stands of three-high mill. The feature is that drive easily, change stands quickly, axial fixing on one end. It also has advantages of improve the side’s accuracy and reduce metal loss. It makes the size of production approaching to the size of the end production to reduce the number of cold drawing. It makes the design more perfect. During making process systems, a set of deformation system, heating system, rolling speed system should be decided, the decision of these deformation system shows that the design is complete and accurate. Simultaneously parameters of the calculation of the maximum pressure and rolling moment, checking biting, Roll strength and motor ability.
Cold drawing process is cold drawing, including the empty brandy drawing, short sunk drawing, long sunk drawing, floating sunk drawing and expanding drawing. This process’s main process is short sunk drawing, Compared to Hot-roll, cold drawing has advantages of accurate size, large standard and so on, but also has disadvantages of large metal loss and middle complex process. Drawing process, which should be resolved to determine drawing, choose pulling machine tonnage to develop a series of brandy tabulation process norms. Meanwhile, the support process after drawing has the same effect on the quality of pipe, including Hammering, pipe pickling, heat treatment, such as lubrication. Φ 19×2mm石油裂化管工艺设计(2):http://www.751com.cn/jixie/lunwen_30900.html