Ways to improve the quality of cold drawn seamless pipes

To enhance the quality of cold-drawn seamless pipes, manufacturers can adopt several key measures throughout the production process.

Optimize the Heating Process
If the heating temperature is too high or prolonged, zinc ash can adhere to the surface of the tube blank, making it difficult to remove. To avoid incomplete phosphorus removal caused by improper heating, the heating time should be adjusted based on steel grades and specifications under the standard production process.

Refine the Phosphorus Removal Process
Conduct four rounds of phosphorus removal during the rough rolling stage to ensure the initial zinc ash is effectively removed. In the fine rolling stage, increase the frequency of phosphorus removal based on the thickness of the cold-drawn pipe. For pipes with a thickness of 20-30 mm, an additional round of fine phosphorus removal should be implemented. For thicker pipes (over 30 mm), further phosphorus removal rounds are necessary, ensuring the total number of phosphorus removals meets the requirements for improved quality.

Implement Laminar Flow Cooling
Use laminar flow refrigeration technology on intermediate billets. After rolling, this process helps the steel plate maintain a good shape, with the surface layer exhibiting a gray-green, high-density finish, thereby enhancing surface quality.

Extend Billet Length
Apply an extension design to the first and last raw materials, modifying the material at the beginning and end of special-shaped steel plates to improve consistency and quality throughout the rolling process.

Enhance the Production Process
Improve cold rolling techniques by selecting flat rolling methods for various specifications. This approach reduces both cold rolling time and oxidation time at high temperatures, leading to improved surface quality for the pipes.

Adjust Unwinding Furnace Temperature
Once unwinding standards are met, the temperature of the unwinding furnace should be reduced moderately. Consider the steel grade, product thickness, and cross-sectional width to optimize furnace temperature and minimize defects caused by loop formation.

Increase Finish Rolling Temperature
Moderately raise the finish rolling temperature to enhance the plastic deformation of surface zinc ash without compromising the characteristics of the cold-drawn seamless pipes. This adjustment further improves surface quality and pipe durability.

These measures ensure a higher quality cold-drawn seamless pipe, enhancing both performance and longevity.