
1. Round Steel: The surface of the round steel must be smooth with no obvious dents or cracks. Next, inspect the cross-section of the seamless pipe for any cracks. It's also essential to test the material of the raw materials. Tian Zhan Steel Pipe strictly selects high-quality round steel from Jiangsu's leading manufacturers such as Zhongtian, Huai Steel, and Changqiang, ensuring product quality.
2. Round Steel Piercing: Tian Zhan Steel Pipes measures the center point and drills a center hole to ensure the eccentricity issue of the finished steel pipes.
3. Tubing: Seamless tube tubing should have even wall thickness and minimal surface defects on both inner and outer surfaces; equipment for external surface polishing and internal hole defect cleaning should be provided.
4. Pickling + Phosphatizing + Saponification: The primary purpose of pickling is to remove the oxide scale from the inner and outer surfaces of steel pipes. Phosphatizing and saponification are aimed at lubricating the steel pipes to prevent scratching during the cold drawing process.
5. Post-Acid Cleaning Inspection of Billets: Compared to standard Q345B square rectangular steel pipes, Tianzhan Steel Pipes' cold drawn seamless steel pipe production process includes an additional hot rolled billet acid cleaning inspection. This is primarily to ensure that the outer surface of the billet is free of folds, cracks, and other defects, and to exclude billets with internal folds, severe scratches, and rough surfaces.
6. Heat Treatment: Annealing is a crucial process in the production of all cold-drawn seamless steel tubes, as the quality of annealing affects both the performance of the tubes and the removal of iron oxide scale. Q345B square rectangular tubes require equipment for non-oxidizing bright annealing.
7. Cold Drawing: Q345B square and rectangular steel tubes find extensive application in industry. Tian Zhan focuses on several common issues during production to ensure high-quality finished products. For instance, surface transverse scratches on cold drawn seamless steel tubes, cracking at the tube ends, improper cutting, shape deviation, etc. 8. Straightening: During the straightening process of steel tubes, an appropriate amount of pressure must be applied. Moreover, constant attention should be given to any surface indentations or scratches. If any issues are found, they should be addressed promptly. 9. Inspection: Professional measuring tools are used during the inspection of seamless tubes to check the inner and outer diameters, wall thickness, tolerance for inner and outer diameters, ellipticity, length, bend, end face bevel angle, and burr.































