Alloy 329 stainless steel seamless pipes are highly regarded for their exceptional combination of corrosion resistance, mechanical strength, and versatility, making them a preferred choice in various industrial applications. Below is a detailed introduction covering parameters, standards, performance, equivalent grades, packaging, and applications.
1. Key Parameters of 329 Stainless Steel Pipe
- Material Grade: Alloy 329 (a duplex stainless steel, typically composed of ~26-30% Cr, ~3-5% Ni, ~1-2% Mo, with balanced austenitic and ferritic phases).
- Product Type: Seamless pipe/tube (no welding seams, ensuring uniform strength and integrity).
- DN Range: DN10 (nominal diameter 10mm) to DN300 (nominal diameter 300mm).
- Wall Thickness: Compliant with ANSI B36.10, ranging from SCH 5S to SCH 160 (e.g., DN50 may have wall thicknesses like 2.77mm, 3.91mm, 6.35mm, etc., depending on the schedule).
- Outer Diameter (OD): Corresponding to DN sizes, e.g., DN10 ≈ 17.1mm OD, DN300 ≈ 323.9mm OD (per ANSI B36.10 specifications).
- Length: Common lengths include 6m, 12m, or customized lengths as per customer requirements.
- Surface Finish: Pickled, polished (2B, BA), or sandblasted, depending on application needs.
2. Standards Compliance of 329 Stainless Steel Pipe
- Primary Standard: Manufactured in accordance with ANSI B36.10 (American National Standard for Welded and Seamless Wrought Steel Pipe), governing dimensions, wall thicknesses, and tolerances.
- Additional Standards: May also comply with ASTM A789 (Standard Specification for Seamless and Welded Ferritic/Austenitic Duplex Stainless Steel Pipe), ASTM A790 (for tubes), or EN 10216-5 (European standard for seamless duplex steel pipes) for specific markets.
3. Performance Characteristics of 329 Stainless Steel Pipe
- Corrosion Resistance: Excellent resistance to general corrosion, pitting, and crevice corrosion, especially in chloride-containing environments (e.g., seawater, brines) due to its high chromium and molybdenum content. Superior to many austenitic stainless steels (e.g., 304) in harsh conditions.
- Mechanical Strength: High tensile strength (typically 620-800 MPa) and yield strength (≥310 MPa), significantly higher than austenitic grades, making it suitable for high-pressure applications.
- Heat Resistance: Good stability at moderate temperatures (up to ~300°C); avoids brittle phases formation under continuous exposure to high heat.
- Weldability: Moderate weldability with proper techniques (e.g., low heat input to maintain duplex phase balance); post-weld heat treatment is often unnecessary.
- Formability: Fair formability, though less ductile than austenitic stainless steels, requiring careful handling during bending or forming.
4. Equivalent Grades
Alloy 329 has counterparts in different standard systems:
- ASTM: S32900
- UNS: S32900
- DIN: 1.4460
- EN: X2CrNiMoN29-7-2 (similar composition and properties)
5. Packaging of 329 Stainless Steel Pipe
- Pipes are bundled with steel straps, separated by wooden or plastic spacers to prevent scratches.
- Each bundle is labeled with details: material grade, size (DN/OD/wall thickness), length, standard, heat number, and manufacturer information.
- For export, pipes may be packed in wooden crates or containers with moisture-proof wrapping to protect against corrosion during transportation.
6. Applications of 329 Stainless Steel Pipe
Alloy 329 seamless pipes are widely used in industries requiring a balance of strength and corrosion resistance:
- Oil and Gas: Downhole tubing, offshore platforms, and pipeline systems handling corrosive fluids.
- Chemical Processing: Reactors, heat exchangers, and piping for acids, alkalis, and chloride solutions.
- Marine Engineering: Seawater intake systems, ship hulls, and desalination plants.
- Water Treatment: Pipelines for wastewater treatment and industrial water circulation.
- Power Generation: Condenser tubes and piping in fossil fuel or nuclear power plants.