Industrial Stainless Steel Pipes

• ​Introduction

Industrial stainless steel pipes are alloy pipes with iron as the matrix and a chromium content of not less than 10.5%. Their unique corrosion resistance stems from an extremely thin and dense chromium oxide passive film formed on the surface by chromium. This film not only prevents the metal matrix from being oxidized but also has a self – repairing function. When the surface is damaged, chromium will recombine with oxygen to form a new passive film. For this reason, industrial stainless steel pipes have become key materials to ensure production safety and efficiency in fields such as chemical industry, energy, and food processing that have strict requirements on material performance.

• ​Main Functions

Fluid Transportation：In the petrochemical industry, industrial stainless steel pipes can transport various highly corrosive chemical media, such as sulfuric acid and nitric acid. Their corrosion resistance can effectively prevent medium leakage caused by pipeline corrosion. In the food processing industry, because stainless steel pipes have smooth surfaces and are easy to clean, meeting food hygiene standards, they are often used to transport food raw materials such as milk and fruit juice. In heating systems, they can withstand the long – term scouring of high – temperature hot water, ensuring the stability of hot water transportation.

Structural Support：In bridge construction, some load – bearing structures use industrial stainless steel pipes. With their high strength and weather resistance, they can resist the long – term effects of wind and rain erosion and vehicle loads. In mechanical equipment manufacturing, as the support frame of precision components, they can ensure the stability of components during high – speed operation and reduce the impact of vibration on equipment accuracy. In addition, in the construction of offshore platforms, the seawater corrosion resistance of stainless steel pipes makes them ideal structural support materials.

• ​Tubing Standards

ASTM A312, ASTM A213, ASTM A240，ASTM A269，ASTM A268，ASTM A789 ; EN 10312，EN 10217-7，EN 10216-5 ; GB/T 14976，GB/T 21833 .

• Material & Performance

304/304L，316/316L，310S，321，904L，430，2205，2507 etc. 1.4301/1.4306,1.4401/1.4404,1.4006,1.4016,1.4462,1.4410 etc.

Exceptional Corrosion Resistance：Stainless steel seamless tubes can resist a wide range of corrosive substances, making them suitable for transporting corrosive media in the Petroleum and Chemical Industry, seawater in Seawater Desalination, etc. The self – repairing passive oxide film ensures continuous protection.​

Superior Pressure Resistance：The seamless structure enables the tubes to withstand high internal and external pressures, which is essential for applications in high – pressure pipelines of the Energy and Power Industry and Marine Engineering.​

High – Temperature and Low – Temperature Performance：Maintaining good mechanical properties across a broad temperature range, these tubes are applicable in high – temperature scenarios of the Energy and Power Industry and low – temperature environments in some specialized food processing.​

Hygienic and Non – Toxic：This property makes them ideal for the Food and Beverage Processing and Medical Equipment Manufacturing industries, ensuring product safety and hygiene.​

High Ductility and Toughness：Allows for complex shaping and processing, meeting the diverse requirements of different core application industries, from the precise manufacturing of medical equipment to the structural design in Construction and Decoration.

Passivation Film Stability: A dense oxide film forms on the surface after passivation, further enhancing corrosion resistance.

Workability & Weldability:Good cold formability: Can be processed by bending, flaring, etc., suitable for complex structure manufacturing.

Mature Welding Processes: Using TIG, HFIW, etc., the weld strength can reach over 90% of the base metal, with corrosion resistance close to that of the substrate.

• ​Manufacturing Process

Raw Material Preparation- Selection: High-purity stainless steel round billets.

Heating Process- Protective Atmosphere Heating: Heated in a protective furnace filled with nitrogen (N₂) or argon (Ar) to 1100~1250℃ ,with heating rate ≤5℃/min to avoid thermal cracking.

Piercing & Forming- Piercing: Hollow billets are formed by two-roll skew rolling.

Rolling & Sizing- Multi-pass Rolling: Extended rolling by continuous tube mill.

Heat Treatment- Solution Treatment: Heated to 1050~1150℃ and water-quenched to dissolve carbides into austenite, enhancing corrosion resistance; martensitic steels (e.g., 410) require annealing for stress relief.

Surface Treatment: Pickling & Passivation- Electro-polishing (Optional): For food/medical grade tubes, Ra≤0.8μm achieved via electro-polishing; Sizing & Straightening- Diameter tolerance controlled by sizing mill and straightene.

Testing- Corrosion resistance: Intergranular corrosion test , salt spray test; Mechanical properties: Tensile test , hardness test.

• Specifications