Stainless Steel Pipes | 904L/2205 Ultra-Low Carbon Design

Stainless Steel Pipes | 904L/2205 Ultra-Low Carbon Design

Product Specifications

Engineered for extreme durability and corrosion resistance, our stainless steel pipes meet global standards for industrial, marine, and chemical applications.

Key Attributes

1. Material Composition

   • 904L (UNS N08904): 19–23% Chromium, 23–28% Nickel, 4–5% Molybdenum, 1–2% Copper. Ultra-low carbon (≤0.02%) prevents carbide precipitation during welding.
   • 2205 Duplex (UNS S32205): 22–23% Chromium, 4.5–6.5% Nickel, 3–3.5% Molybdenum. Dual-phase structure (50% austenite + 50% ferrite) enhances chloride resistance.

2. Applications

   • 3 inch stainless steel exhaust pipe: Ideal for high-temperature automotive/marine exhaust systems (up to 450°C for 904L, 300°C for 2205).
   • schedule 40 stainless steel pipe: Used in chemical processing, oil/gas pipelines, and hydraulic systems requiring pressure ratings up to 2,000 PSI.
   • stainless steel pipe fittings: Custom elbows, tees, and flanges for seawater cooling, sulfuric acid reactors, and offshore platforms.

3. Manufacturing Process

   • Seamless Pipes: Hot extrusion (1,100–1,200°C) followed by cold drawing for precision tolerances (±0.1mm).
   • Welded Pipes: High-frequency induction welding (HFIW) with argon shielding to prevent oxidation.
   • Post-weld heat treatment (PWHT) at 1,040–1,120°C for stress relief and enhanced corrosion resistance.

Technical Performance

Tensile & Bend Strength

• 904L: Tensile strength ≥490 MPa and elongation ≥35% ensure ductility in acidic environments (e.g., sulfuric acid reactors). Its copper content improves resistance to reducing acids.
• 2205: Yield strength ≥450 MPa and bend radii up to 1.5× pipe diameter make it ideal for stainless steel pipe fittings in seismic zones.

Weight Calculation Formula

Calculate pipe weight (kg/m) using:
Weight=1000(OD−WT)×WT×0.02491
Example: A 3 inch stainless steel exhaust pipe (76.2mm OD, 3mm WT) weighs 5.5 kg/m for 904L and 5.7 kg/m for 2205.

Identification Marking

Pipes are laser-etched with:

• Grade (e.g., UNS N08904/S32205)
• Heat number and certification codes (e.g., ASTM A312, EN 10216).

Why Does Stainless Steel Rust?

Despite corrosion resistance, localized rust may occur due to:

1. Chloride Exposure: Coastal environments or de-icing salts accelerate pitting in 2205 duplex.
2. Galvanic Corrosion: Contact with carbon steel in stainless steel pipe fittings triggers electrochemical degradation.
3. High-Temperature Oxidation: Prolonged exposure above 300°C degrades 2205’s ferritic phase.
4. Welding Defects: Improper PWHT in 904L causes chromium depletion in heat-affected zones.

Prevention Strategies:

• Use insulating gaskets in schedule 40 stainless steel pipe joints to block galvanic currents.
• Select 904L for sulfuric acid environments (up to 98% concentration at 40°C).
• Regular passivation with nitric acid to restore oxide layers.

Why Choose Our Stainless Steel Pipes?

1. Certified Quality: ISO 9001, PED, and NACE compliance with third-party inspections.
2. Custom Solutions: Tailored stainless steel pipe fittings and diameters (3mm–2.5m) for complex installations.
3. Global Logistics: Warehouses in Shanghai, Houston, and Rotterdam ensure 7–15-day delivery.
4. Lifetime Warranty: 25-year guarantee against corrosion and material defects.