Corrosion-Resistant Stainless Steel Welded Pipe 304/316L ASTM A312 for Construction Structure
1. Product Description
Stainless steel welded pipe is a tubular product manufactured by cold-forming stainless steel coil or strip into a tubular shape and then longitudinally welding the seam using continuous high-frequency or tungsten inert gas (TIG) welding. The weld zone is typically subjected to solution annealing or post-weld heat treatment to restore corrosion resistance and mechanical properties. Depending on the application, the pipe can be produced as cold-rolled or hot-rolled, with either single-weld or spiral-weld configurations. Common material grades include austenitic (304/304L, 316/316L), ferritic (409, 430), martensitic (410), and duplex (2205, 2507) stainless steels. The product conforms to international standards such as ASTM, EN, JIS, and GB, ensuring high quality and traceability.
2. Product Applications
Oil & gas upstream/midstream – gathering lines, flow lines, and pipeline transportation for corrosive media
Chemical and petrochemical – process piping, heat exchangers, and reactor internals
Water and wastewater treatment – desalination plants, sewage treatment, and potable water supply
Food and beverage – sanitary tubing for dairy, beer, and juice processing (meeting FDA and 3A standards)
Pharmaceutical and biotechnology – clean steam, WFI (water for injection), and CIP/SIP systems
Construction and infrastructure – bridge handrails, curtain wall supports, staircases, and decorative tubes
Automotive and heavy machinery – exhaust systems, structural frames, and hydraulic cylinders
Power generation – condenser tubing, boiler feedwater, and nuclear-grade applications (where applicable)
Superior corrosion resistance – high chromium and nickel content provide excellent resistance to pitting, crevice corrosion, and stress corrosion cracking, especially in chloride-rich environments.
Weld integrity – advanced welding techniques (TIG + plasma, ERW, or laser) ensure a narrow heat-affected zone (HAZ) and minimal sensitization, with optional pickling and passivation to remove weld discoloration.
High dimensional accuracy – modern forming mills and sizing rollers guarantee tight tolerances on outer diameter (OD), wall thickness, and ovality, reducing installation difficulties.
Cost efficiency – lower raw material cost and higher production speed than seamless pipes, with consistent quality suitable for mass production.
Long length capability – available in up to 20 meters or custom coils, reducing the number of field welds and lowering total installed cost.
Excellent surface finish – options include 2B, BA, No.4, mirror polish, and brushed, facilitating cleaning and aesthetic appearance.
Environmentally friendly – 100% recyclable material with long service life, contributing to green building and sustainable design.

4.Key Technical Parameters
| Parameter | Typical Range / Details |
| Material Grades | Austenitic: 304, 304L, 316, 316L, 310S, 321; Ferritic: 409L, 430; Martensitic: 410, 420; Duplex: 2205, 2507; Super austenitic: 904L |
| Outer Diameter (OD) | Round: 6 mm – 1200 mm (welded); up to 4800 mm for spiral welded; Square/Rectangular: 10×10 – 600×400 mm |
| Wall Thickness | 0.3 mm – 25 mm (longitudinal); up to 50 mm for spiral |
| Length | Standard: 6 m; Custom: 1 m – 20 m or coil form |
| Dimensional Tolerances | OD: ±0.5% (typical); WT: ±10%; Straightness: ≤1.5 mm/m; Ovality: ≤1% of OD |
| Weld Finish | As-welded, ground flush, or polished; heat tint removed by pickling or electropolishing |
| Mechanical Properties (min) | 304: Yield ≥205 MPa, Tensile ≥520 MPa, Elong ≥40%; 316L: Yield ≥170 MPa, Tensile ≥485 MPa, Elong ≥40%; 2205: Yield ≥450 MPa, Tensile ≥620 MPa, Elong ≥25% |
| NDT & Testing | Hydrostatic test, pneumatic test, eddy current (ET), ultrasonic (UT), radiography (RT) – as per standard requirements |
| Surface Roughness | Ra ≤ 0.8 μm (for sanitary), Ra ≤ 2.5 μm (for industrial) |
| Applicable Standards | ASTM A312/A358/A778/A790; EN 10217-7; JIS G3459/G3463; GB/T 12771-2019; also for sanitary: ASTM A270, EN 10357 |
| End Finishes | Plain end, beveled end, threaded, grooved, or flanged |
| Packing | Bundled with plastic caps, wrapped in woven cloth, or wooden crates for export |
FAQ
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