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The Production Process of 27SiMn Cold-Drawn Tubes – A Favorite in the Coal Mining Machinery Industry
Views: 0 Author: Site Editor Publish Time: 2025-09-15 Origin: Site
In the Brilliant Galaxy of Pipes for the Coal Mining Machinery Industry, 27SiMn Cold-Drawn Tubes Shine Like a Dazzling Star
It is no ordinary pipe, but one that showcases remarkable performance and excels in numerous fields. Today, let’s take an in-depth look at this favorite in the coal mining machinery industry — the 27SiMn cold-drawn tube.
The Production Process of 27SiMn Cold-Drawn Tubes
1. Raw Material Selection
High-quality raw materials are the foundation for producing high-performance 27SiMn cold-drawn tubes. Jianlida strictly screens 27SiMn steel that meets standards, ensuring its chemical composition and physical properties align with requirements. Our raw materials are sourced from well-known domestic steel mills, such as Tianjin Seamless Steel Pipe Group and Baosteel, guaranteeing the quality of raw materials from the very source.
2. Preparation Before Cold Drawing
After selecting the raw materials, a series of pre-treatments are carried out, including pickling/phosphating/saponification, cutting, and quenching-tempering. Meanwhile, strict quality inspections (such as flaw detection) are conducted on the raw materials to ensure there are no internal defects in the seamless tubes — laying a solid foundation for the subsequent cold drawing process.
Pickling/Phosphating/Saponification: Pickling removes oxide scale and rust from the tube surface; phosphating forms a protective film to enhance lubrication; saponification further coats the surface with a lubricating layer, reducing friction during cold drawing.
Flaw Detection: Non-destructive testing (e.g., ultrasonic testing) is used to identify hidden defects like internal cracks or inclusions, preventing substandard materials from entering the next process.
3. Cold Drawing Process
Cold drawing is the core step in manufacturing 27SiMn cold-drawn tubes. The raw material tubes are pulled through a series of dies of different specifications. Without heating, the outer diameter of the tubes is gradually reduced, and the wall thickness is uniformly thinned. During this process, parameters such as drawing speed and drawing force are precisely controlled to ensure the dimensional accuracy and surface quality of the tubes.
Die Selection: Dies of matching specifications are used according to the target size of the finished tube, ensuring the tube’s outer diameter and wall thickness meet design requirements.
Parameter Control: Drawing speed is typically kept at 5–15 m/min, and drawing force is adjusted based on the tube’s thickness and material hardness — avoiding issues like surface scratches or tube cracking caused by improper parameters.
4. Post-Processing
After cold drawing, the tubes undergo a series of post-processing procedures to optimize their performance and quality.
Annealing Treatment: This is a key step. By heating the cold-drawn tubes to a specific temperature (680–720°C), holding the temperature for a set duration, and then cooling slowly, internal stresses generated during cold drawing are eliminated. This restores the tube’s good toughness and ductility, preventing brittle fracture in subsequent use.
Straightening: Coarse and fine straightening processes are performed using hydraulic straightening machines to ensure the straightness of the cold-drawn tubes (meets the requirement of ≤1 mm/m) and improve their appearance.
Final Quality Inspection: Rigorous tests are conducted, including dimensional accuracy inspection (using calipers and micrometers to check outer diameter, wall thickness, etc.), mechanical property testing (tensile strength, yield strength, impact toughness), and surface quality inspection (visual inspection or eddy current testing for scratches, pits, etc.). Only tubes that meet all standards receive a qualification label and enter the market for circulation.
The 27SiMn cold-drawn tube, with its unique performance, wide range of applications, and continuous innovation potential, rightfully earns its title as a “favorite” in the coal mining machinery field. It is believed that in the future, it will continue to shine, bringing more convenience and reliability to industrial production. If you have more questions about 27SiMn cold-drawn tubes, please feel free to contact us for inquiries!
