Briefly describing the process features of U-shaped radiant tubes

 

Precision Centrifugal Casting Production Process

Centrifugal casting is the core advanced process for manufacturing high-performance U-shaped radiant tubes. Its main steps include:

 

1. Mold and Melting Preparation: Selected heat-resistant alloy raw materials are precisely melted in a high-temperature furnace to ensure that the chemical composition meets the required standards. Simultaneously, the metal mold (tube) is preheated to a specific temperature and its inner surface is sprayed with a refractory coating.

 

2. Centrifugal Casting: This is the most critical step. The preheated mold is rotated at high speed, and then a precisely measured amount of hot molten metal is poured into the rotating mold. Under the strong centrifugal force, the denser molten metal is pushed toward the inner wall of the mold, while impurities and gases are concentrated in the mold cavity (the future inner surface of the tube), achieving directional solidification from the outside in.

 

3. Cooling and Demolding: After the casting has fully cooled and solidified, the rotation is stopped and the formed tube blank is removed from the mold. The result is a dense, pore-free, fine-grained, seamless straight tube with excellent mechanical properties.

 

4. Heat Treatment and Machining: The raw tube undergoes necessary heat treatment (such as solution treatment) to optimize its metallographic structure and mechanical properties. The tube's inner and outer diameters are then machined using precision machine tools to ensure dimensional accuracy and surface finish.

 

5. Cold Forming and Final Finishing: The processed seamless straight tube is cold-bent into a precise U-shape using a large tube bending machine. Finally, polishing, inspection (such as non-destructive testing), and pressure testing are performed to ensure the quality of the finished product.

 

In summary, the centrifugal casting process endows U-shaped radiant tubes with seamlessness, density, uniformity, and high strength, making them ideal for high-temperature, long-cycle, and high-reliability industrial heating applications. It represents the technological benchmark for high-end radiant tube manufacturing and is the core guarantee of high-quality heat treatment.