In the manufacturing of API 5L X52 seamless steel pipe, the hot forming manufacturing process involves two main methods: hot rolling and hot extrusion. Hot rolling is mainly used to produce composite pipe joints, while hot extrusion is suitable for the production of seamless composite pipes.
First, the raw materials should be prepared. Select high-quality steel billets that meet the standards to ensure that their chemical composition ratio is appropriate, including appropriate elements such as carbon, manganese, silicon and alloying elements. At the same time, the steel billets are strictly inspected to check for surface defects and internal quality problems.
Next is the heating step. The steel billets are placed in a heating furnace and heated to about 1200-1300°C. This temperature makes the steel billets softer and easier to process. During the heating process, attention should be paid to controlling the temperature uniformity to prevent quality problems caused by temperature differences.
Then the piercing operation is carried out. The heated steel billet is moved to the piercing machine, and the piercing mandrel and roller are used to form a hollow tube billet during the rotation and advancement of the steel billet. This process requires precise control of parameters such as piercing speed, mandrel position and roller pressure.
Then comes the rolling stage. The tube billet is first rolled, and multiple sets of rollers gradually make its outer diameter and wall thickness close to the standard size. Then it enters the finishing rolling to further improve the accuracy and surface quality. During this period, the roller spacing and speed should be adjusted according to the requirements.
Then sizing and straightening are carried out. The sizing machine accurately controls the outer diameter of the steel pipe within the tolerance range through the ring die. The straightening machine corrects the bending or ovality of the steel pipe to keep it straight.
In the cooling step, select the appropriate cooling method according to the performance requirements of the steel pipe, such as natural cooling, air cooling or water cooling, and control the cooling speed to obtain the ideal metallographic structure.
Finally, it is finishing and inspection. Cutting, beveling and other operations are carried out according to customer needs, and then the steel pipe is fully inspected, including appearance, size, mechanical properties and non-destructive testing. After passing the inspection, it is packaged and stored, and the steel pipe is protected by spraying paint, oiling, etc., and stored in a dry and ventilated warehouse, and classified storage is easy to manage.
Carbon Steel Line Pipe
