2205 Duplex Stainless Steel Pipe - Detailed Introduction

1. Basic Overview

2. Chemical Composition (Mass Fraction)

3. Key Properties

3.1 Corrosion Resistance

• Superior pitting and crevice corrosion resistance: The high molybdenum and nitrogen content endow it with a PREN (Pitting Resistance Equivalent Number) of over 40, far exceeding 316L stainless steel.
• Resistance to chloride corrosion: Ideal for seawater, salt spray, and chloride-containing environments (e.g., marine engineering, desalination plants).
• Resistance to acid and alkali corrosion: Performs well in weak acid, weak alkali, and organic acid media.

3.2 Mechanical Properties

• High strength: Its tensile strength is twice that of austenitic 304/316 stainless steel, reducing wall thickness and material cost under the same pressure conditions.
• Good toughness: Maintains excellent toughness at both low and high temperatures.

3.3 Weldability & Processability

• Excellent weldability: Can be welded by TIG, MIG, and submerged arc welding; post-weld annealing is not mandatory for most applications (simplifies construction).
• Easy processing: Can be bent, flanged, and threaded, with good formability.

3.4 Cost-Effectiveness

4. Specifications & Sizes

4.1 Compliance Standards

• American Standard: ASTM A789 (seamless pipe), ASTM A790 (welded pipe)
• European Standard: EN 10217-7, EN 10216-5
• Chinese Standard: GB/T 21832, GB/T 13296

4.2 Dimensions (Customizable)

4.3 Surface Treatment

• Pickled & Annealed (BA/2B finish)
• Polished (Mirror polish, Hairline finish)
• Sandblasted / Coated (as per customer requirements)

5. Production Process

5.1 Seamless 2205 Stainless Steel Pipe

1. Raw material preparation: High-quality 2205 billet
2. Piercing: Hot piercing to form a hollow billet
3. Hot rolling/cold rolling: Form the final outer diameter and wall thickness
4. Heat treatment: Annealing in a protective atmosphere to stabilize the microstructure
5. Inspection: Ultrasonic testing (UT), hydraulic testing, dimensional inspection, surface inspection

5.2 Welded 2205 Stainless Steel Pipe

1. Slitting & coiling: Slit the steel strip and roll into a tube blank
2. Welding: TIG/MIG high-frequency welding to form the pipe
3. Sizing & shaping: Adjust the diameter and roundness
4. Heat treatment & pickling: Remove welding stress and oxide scale
5. Finishing & inspection: Polishing, cutting, and quality testing

6. Main Application Fields

1. Petrochemical Industry: Oil and gas transmission, refinery pipelines, chemical processing equipment (resistant to chloride, acid, and alkali corrosion).
2. Marine & Offshore Engineering: Seawater desalination pipelines, ship hull piping, offshore platform structures (resist seawater corrosion and marine atmosphere).
3. Paper & Pulp Industry: Pulp conveying pipelines, bleaching equipment (resist chloride and acid corrosion in pulping).
4. Energy & Power Industry: Waste heat recovery systems, thermal power plant pipelines, geothermal engineering.
5. Food & Beverage Industry: High-purity fluid transportation ( meets food-grade hygiene requirements after polishing).
6. Water Treatment: Urban sewage treatment, industrial circulating cooling water systems.

7. Product Advantages

1. Dual-phase structure advantage: Combines the high toughness of austenitic steel and the high strength of ferritic steel.
2. Long service life: Reduces maintenance and replacement costs in harsh environments.
3. Customization support: Can produce pipes of special specifications, surfaces, and lengths according to customer project requirements.
4. Third-party certification: Provide certificates such as MTC (Material Test Certificate), ISO, CE, SGS to ensure product quality.

8. Packaging & Delivery

8.1 Packaging

• Inner layer: Anti-rust oil + plastic film / anti-rust paper
• Outer layer: Plywood case / steel pallet (fixed with steel strips to prevent damage during transportation)
• Marking: Product specifications, standards, batch numbers, and manufacturer information are clearly marked.

8.2 Delivery

• Lead time: 7-25 working days (depending on order quantity and customization)
• Shipping: By sea, air, or express (DHL, FedEx, TNT)
• Supply ability: 500-5000 tons per month (stable mass production)

9. Quality Inspection

1. Dimensional inspection: OD, WT, roundness, length accuracy
2. Non-destructive testing: Ultrasonic testing (UT) for internal defects, hydraulic testing for pressure resistance
3. Chemical composition analysis: Spectrometric testing to confirm compliance with standards
4. Mechanical property testing: Tensile, hardness, and impact tests
5. Surface inspection: No cracks, pits, or inclusions on the surface