904L Austenitic Stainless Steel Seamless Tube for Corrosive Environments

Founded in 2006, SMLSCO is a leading global stockist of stainless steel piping systems. The company specializes in the supply of seamless pipes, pipe fittings, and flanges from stock. With a standing inventory of over 3,000 metric tons and international certifications such as PED, ISO, and AD2000, we are able to provide rapid delivery within two weeks to distributors worldwide. SMLSCO is committed to providing reliable supply chain support for demanding sectors such as the chemical, energy, and marine engineering industries through transparent quality management processes.

The production of seamless tubes typically begins with high-quality tube blanks, which undergo a series of processes including cold rolling, cold drawing, degreasing and cleaning, bright annealing, straightening, polishing, and cut-to-length cutting. The core of this entire process is to further enhance the dimensional accuracy, surface quality, and cleanliness of the tubes while ensuring material properties, making the products more suitable for heat exchangers, instrumentation piping, and other industrial systems with high requirements for internal and external surface quality and stability.

In the aforementioned production process, bright annealing is a critical step that influences the quality of the finished seamless tube. Bright annealing is a heat treatment performed in a protective atmosphere. Its primary functions are to eliminate internal stresses resulting from cold working, restore the material’s plasticity, and maintain a clean, bright surface on the tube. For seamless tube products, this not only enhances subsequent processing and performance but also makes them more suitable for applications with high requirements for cleanliness and corrosion resistance.

904L is an austenitic stainless steel containing high proportions of nickel, molybdenum, and copper. This unique chemical composition gives it excellent corrosion resistance when handling strong reducing media such as dilute sulfuric acid. Compared to conventional 316L, 904L offers superior resistance to pitting and crevice corrosion and effectively withstands high-chloride environments. With its low carbon content, 904L maintains good intergranular corrosion resistance even after welding or heat treatment, making it an ideal choice for demanding chemical processes and acidic operating conditions.

• Polished Tube / BA Tube: For both LCL and FCL shipments, tubes are packed in plywood crates. Each tube is individually wrapped in a plastic bag, and plastic protective caps are fitted to the tube ends.

• Pickled (AP) Tube: For FCL shipments, tubes are packed in woven bags or plywood crates, with plastic protective caps fitted to the tube ends; for LCL shipments, tubes are packed in plywood crates, with plastic protective caps fitted to the tube ends.