Processing requirements and application of steel radiator pipe
July 05 09:25:07, 2025
In recent years, the development of steel radiators has accelerated significantly, with a growing emphasis on aesthetics, design, and functionality. As a result, user expectations for radiators have become more diverse and demanding. However, the market is currently flooded with low-cost steel pipes that often do not meet quality standards. Many manufacturers use substandard materials to cut costs, such as cold-rolled hard strip steel, which lacks the necessary durability. Some products only meet single-specification requirements, while still having a black oxide layer on the surface, reducing coating adhesion and corrosion resistance, ultimately shortening the product’s lifespan.
The residual stress caused by uneven cooling during production also leads to deformation, instability, and reduced pressure performance. Most users are unable to detect these issues at first glance. However, after removing the oxide layer through gas protection annealing, bright strips show improved surface finish, uniform temperature distribution, stable microstructure, and enhanced resistance to deformation, greatly extending the service life of the steel tubes.
To ensure product quality and regulate the market effectively, it's essential to follow standardized manufacturing processes. High-quality Q195 material is used as the raw material, known for its stability and compliance with industry standards. Each step in the production process is strictly controlled to maintain consistency and quality. The hot-rolled strip typically has a three-layer oxide scale: Fe₂O₃ on the outer layer, Fe₃O₄ in the middle, and FeO on the inner layer. To meet product specifications, the strip undergoes peeling to remove surface oxides, followed by continuous pickling using a high-speed machine with hydrochloric acid at 15–20% concentration and temperatures between room temperature and 40°C. After pickling, alkali neutralization and sodium nitrite preservation treatments are applied to improve surface quality.
The strip then goes through cold rolling, with rough, medium, and fine rolling stages carefully adjusted based on thickness and plasticity to ensure precise dimensions—typically within 0.01–0.03 mm. The final finish rolling ensures good mechanical properties, such as high strength, low yield limit, and excellent formability. Before this stage, the strip is re-annealed in a nitrogen-protected electric furnace, ensuring uniform heating and eliminating internal stresses, resulting in a smooth, consistent surface.
In the welding process, advanced third-generation solid-state frequency welding technology is employed to ensure a stable and high-quality weld. Unlike traditional high-frequency methods, which suffered from unstable waveforms and inconsistent heat output, solid-state power supplies provide steady energy, reducing defects like under-melting or over-melting. The welding temperature is carefully controlled without sudden changes, preventing sparks and ensuring even heating. This results in a clean weld with no oxide inclusions and consistent composition with the base metal.
Every stage of production follows strict precision requirements, with detailed tooling and process controls in place to guarantee the quality of the final steel pipe. By focusing on corrosion resistance, pressure capacity, and leak prevention, the overall service life of the product is significantly improved. This comprehensive approach ensures that the radiators meet all necessary performance standards, offering reliable, long-lasting, and energy-efficient solutions for end-users.