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304 American standard stainless steel pipe manufacturing industry should be healthy and flourishing
The stainless steel pipe manufacturing industry in the United States is currently facing challenges, but it also holds great potential for growth. With China's rapid economic expansion, the demand for stainless steel pipes has surged, leading to a promising market outlook. However, there remains a significant gap between domestic production and market needs in terms of variety, specifications, quantity, and quality.
In terms of product types, many domestic seamless stainless steel pipes still rely on outdated grades like 1Gr18Ni9Ti, which have been phased out in other countries. The quality of urea-grade and high-precision stainless steel pipes produced domestically is inconsistent, while critical components such as heat exchanger tubes for power plants and urea pipes for fertilizer plants are largely imported. Additionally, duplex stainless steel pipes, known for their excellent corrosion resistance, are rarely manufactured within the country.
Regarding specifications, large-diameter and ultra-long stainless steel pipes are still in short supply, while small and medium-sized pipes are overproduced. In terms of volume, high-standard industrial welded pipes—especially those required for specialized applications—are still lacking in domestic production. Although general-purpose stainless steel pipes meet overall demand, the production of ordinary seamless pipes exceeds market needs, with many low and medium-grade products being oversupplied.
Over the past decade, the application fields of stainless steel pipes have expanded rapidly, driving an increased demand for various materials, sizes, and uses. This high added value has attracted many manufacturers, growing from just a dozen companies in the 1980s to over 400 today. Total production capacity now exceeds 1 million tons, with actual output rising from 50,000 tons in 1989 to 390,000 tons in 1999. Most companies remain small-scale, with annual outputs below 1,000 tons. Over time, steel grades have evolved from austenitic to include martensitic, ferritic, and high-alloy steels, with a wide range of products such as seamless tubes, cold-drawn tubes, and various welded pipes.
While some developed countries produce over 65% of their stainless steel pipes using welding methods, China's production capacity still lags behind domestic demand. It is estimated that the demand for stainless steel welded pipes in China will reach at least 60,000 tons annually in the 21st century.
Domestic production of stainless steel welded pipes mainly uses continuous forming units and the UOE method, with inert gas shielded welding as the primary technique. Thin-walled pipes often use single-gun welding, while thicker industrial pipes may employ multi-gun methods, including plasma plus argon arc welding. Plasma welding, due to its deep penetration capability, is widely used for double-sided welding in thin-walled pipes. The UOE method is typically used for large-diameter and thick-walled pipes, often combined with plasma or argon arc welding.
Advanced technologies such as welding seam tracking and post-weld finishing are now being applied to ensure high-quality industrial pipes. While most heat treatment is still done offline, online heat treatment systems have also been introduced, with five continuous production lines in operation. Brightening furnaces and protective atmosphere heat treatment furnaces are also increasingly used.
The main producers of seamless stainless steel pipes include Shanggang No. 5, Taigang, Daye, and others. Some regions use scrap steel produced by intermediate frequency furnaces. For industrial welded pipes, key producers include Taigang, Zhangjiagang Pohang, Ningbo Baoxin, and Shanggang No. 3, with some raw materials still imported.
Raw materials for decorative stainless steel include imported thin strip steel, cold-rolled narrow bands, slabs from intermediate frequency furnaces, and hot-rolled narrow strips. Despite this, the quality of domestically produced seamless stainless steel pipes remains uneven, indicating room for improvement in both technology and standards.