Views: 0 Author: Site Editor Publish Time: 2024-08-13 Origin: Site
The primary characteristic of seamless tubes is the absence of any welding points or seams throughout the tube body, which results in higher strength and pressure resistance. In modern industry, seamless tubes are widely used in petroleum, chemical, energy, and machinery manufacturing sectors. Understanding and mastering the manufacturing process of seamless tubes is crucial for engineers and technicians in related industries to enhance work efficiency and ensure project quality.
Welded tubes have potential risks of leakage or rupture during actual use, which is due to their manufacturing method. Welded tubes are made by bending steel plates or strips and then welding them, which may result in micro-defects at the welded seams, such as cracks or pores. In contrast, the manufacturing process of seamless tubes does not require any welding or joining steps, thereby eliminating the risks of cracks and pores, and significantly improving the overall reliability and durability of the tubes.
The manufacturing of seamless tubes involves eight processes:
Pipe Blanks Preparation The raw material for seamless tubes is usually round steel billets. The selection of billets determines the performance of the seamless tubes. In this step, billets are inspected to ensure they meet production standards. High-quality billets are then selected and heated to an appropriate temperature for subsequent processing.
Cold Rolling The heated billet undergoes initial piercing to form a hollow shell, which then enters the cold rolling process. Cold rolling involves using multiple rolling mills to gradually reduce the diameter and wall thickness of the hollow shell, enhancing the tube's dimensional accuracy and surface finish, and improving its internal structure. Precise control during the cold rolling process is crucial for the quality of the final product.
Cold Drawing Cold drawing further improves the tube's smoothness and strength, and precisely controls its dimensions. This process involves applying tensile force to the tube at room temperature, increasing its length, reducing its diameter, and making its wall thickness more uniform.
Degreasing Degreasing involves chemical or ultrasonic cleaning to remove oil and grease from the tube surface that may have adhered during cold processing. Clean tubes enhance the effectiveness of subsequent processes and ensure the high quality of the final product, making it essential to remove these contaminants before further processing.
Cutting Precision control in the cutting process is critical, as it directly impacts the application and installation of seamless tubes. Tubes are cut to specified lengths according to production standards and customer requirements, ensuring uniform lengths and avoiding burrs and irregular cut surfaces.
Polishing Polishing improves the surface finish and appearance of seamless tubes, making them more aesthetically pleasing and enhancing their corrosion resistance. The polishing process involves mechanical and chemical polishing to remove surface oxidation and minor defects, achieving a specific level of brightness and smoothness.
Straightening Straightening corrects any bends and deformations that may occur after polishing. A straightening machine applies appropriate force to restore the tube to a straight state, meeting the stringent requirements of engineering and industrial applications for stability and aesthetics.
Bright Annealing Bright annealing is performed in a protective atmosphere to prevent oxidation of the tube surface while enhancing its brightness. Tubes treated with bright annealing exhibit more uniform internal structures, improved mechanical properties, and enhanced corrosion resistance, resulting in a superior appearance and performance, higher reliability, and longer service life.
