Precision seamless pipes require high production and manufacturing standards, with stringent regulations to ensure the quality of the surface layer. The specific design scheme involves a variety of manufacturing elements, which must be proportioned accordingly to ensure optimal results. The production process involves hot rolling, cold rolling, and high temperature and high pressure techniques, all of which require strict adherence to national regulations. The final appearance of the pipes is determined by their internal quality and adherence to specific technical specifications. Manufacturing techniques and specifications must be carefully considered and followed according to national industry standards. The appearance quality of the pipes is one of the key requirements set forth in the national industry standard guidelines.
The allowable range of geometric errors for precision seamless pipes includes specifications like scabs, gaps, curvature, side width, side thickness, included angle, and weight calculation formula. It is important to address any deformations or issues that arise during surface treatment. One common problem is rust on the phosphating part, which can occur due to factors such as high dispersing acid value, excessive Fe2 ion concentration, or insufficient phosphating treatment time. To resolve this, the acid ratio should be adjusted, the tank should be cleaned, or hydrogen peroxide can be used to increase the dissolution time. Another issue is the presence of a non-flat film and air marks. This can be caused by inadequate degreasing, slightly lower phosphating temperature, or the presence of a passivation treatment layer on the precision seamless tube. To address this, the degreasing process should be improved, temperature should be increased, and pickle passivation can be utilized.
The occurrence of a cut on the membrane can be attributed to several factors such as a low phosphating temperature, improper alignment of the precision seamless tube leading to overhanging or overlapping, and an excessive acid ratio. To address this issue, it is recommended to raise the temperature, adjust the gap of the precision seamless tube to ensure proper alignment, and make necessary adjustments in the acid ratio.
Hanging ashes can be a result of precipitation in the plating solution, inadequate cleaning of the phosphating agent, or high levels of the C component in the phosphating agent. To resolve this, the precipitation must be eliminated, and it is advisable to carry out phosphatizing again after pickling and passivation. Additionally, the amount of phosphating agent C should be adjusted accordingly.
The formation of coarse film crystals may occur due to elevated levels of Fe2 positive ion composition, high concentration of phosphating agent C, or excessive working temperature. To overcome this issue, it is recommended to either change the bath solution or utilize hydrogen peroxide. Moreover, the amount of phosphating agent C should be adjusted, and the working temperature should be reduced accordingly.