S31803/S32205 Duplex Stainless Steel Pipe

1.Superior Stress Corrosion Cracking Resistance: Excellent resistance to chloride-induced SCC, outperforming 304 and 316L in high-temperature, chloride-rich environments.

2.High Mechanical Strength: Yield strength (≥450 MPa) is approximately twice that of standard austenitic grades, allowing for thinner wall sections and weight reduction.

3.Excellent Pitting and Crevice Corrosion Resistance: PRE (Pitting Resistance Equivalent) ≥ 34 for S31803 and ≥ 35 for S32205, providing reliable service in seawater and aggressive chemical media.

4.Good Weldability and Fabricability: Maintains balanced ferrite/austenite ratio in the weld zone with proper welding procedures and heat input control.

5.Cost-Effective Alternative: Higher strength and corrosion resistance compared to 316L, enabling reduced material weight and lower overall project costs.

6.International Certification: Pipes can be certified by ABS, BV, DNV, LR, GL, RINA, CCS, KR, and NK, and comply with NORSOK M-630 and ISO 17781 standards for offshore and oil & gas applications.

Womic Steel’s Duplex 2205 pipes conform to multiple international specifications for corrosive and pressure service:

These standards ensure that S31803 / S32205 pipes meet global requirements for chemical composition, balanced dual-phase microstructure, mechanical performance, testing, and dimensional accuracy.

Note: S32205 is a restricted composition range of S31803, offering tighter control of Cr, Mo, and N to enhance corrosion resistance and ensure optimal phase balance. The addition of nitrogen (N) promotes austenite stability and significantly increases pitting resistance.

Impact Toughness (Charpy V-Notch, typical at -40°C): ≥ 60 J (longitudinal)

Heat Treatment Condition:
S31803 / S32205 duplex pipes are solution annealed at 1040–1120°C followed by rapid cooling (water quenching or rapid air cooling). This heat treatment:

Restores the balanced 50/50 ferrite-austenite microstructure.

Dissolves unwanted intermetallic phases (sigma, chi) that can reduce corrosion resistance and toughness.

Relieves internal stresses from forming or welding.

Ensures optimal mechanical properties and corrosion performance.

Critical Note: Unlike austenitic grades (316/316L), duplex stainless steel requires rapid cooling after solution annealing to prevent the precipitation of brittle intermetallic phases.

Delivery Condition: Pipes are normally supplied in solution annealed and pickled condition. Upon request, bright annealing or polished finishes can be provided.

1. Womic Steel adopts advanced production technology to ensure each S31803 / S32205 duplex seamless pipe meets exact specifications with balanced microstructure and flawless surface quality.

2. Raw Material Selection: High-quality duplex 2205 billets from certified mills (Baosteel, TISCO, Outokumpu, POSCO) with certified chemical composition and ferrite/austenite balance.

3. Heating and Piercing: Billets heated to controlled temperature (lower than austenitic grades to prevent ferrite coarsening) and pierced using a rotary piercing mill.

4. Hot Rolling: Shells elongated and rolled to desired intermediate size.

5. Cold Drawing / Cold Pilgering: Pipes refined to precise dimensions with improved surface finish and mechanical properties.

6. Solution Annealing: Critical heat treatment at 1040–1120°C followed by rapid cooling to restore balanced duplex structure.

7. Pickling & Passivation: Removal of oxides and creation of passive film; special pickling acids optimized for duplex grades.

8. Straightening and Dimensional Calibration: Ensures consistent roundness and wall uniformity.

9. Final Inspection & Marking: Each pipe tested (including ferrite content measurement), marked with grade, heat number, and standard before packing.

This process guarantees a balanced dual-phase microstructure, smooth internal bore, high structural integrity, and exceptional corrosion resistance across all batches of Womic Steel’s Duplex 2205 Seamless Pipe.

Womic Steel utilizes state-of-the-art manufacturing technology to ensure every duplex welded pipe meets precise specifications with weld zone phase balance and excellent surface quality.

1.   Raw Material Selection: High-quality S31803 / S32205 duplex stainless steel strips/coils from certified suppliers.

2.   Slitting & Uncoiling: The steel coil is slit to the required width and uncoiled for feeding into the forming mill.

3.   Forming & Welding: The strip is progressively formed into a cylindrical shape. The edges are welded using advanced TIG or Plasma welding with appropriate heat input control and shielding gas (Ar + N₂) to maintain weld zone phase balance.

4.    Weld Seam Treatment: External weld bead removal and optional internal bead control.

5.   Solution Annealing: Full heat treatment of the entire welded pipe at 1040–1120°C followed by rapid cooling – essential for restoring corrosion resistance and balanced microstructure in the weld and HAZ.

6.   Sizing & Calibration: Final precise outer diameter and roundness.

7.   Pickling & Passivation: Chemical treatment removes scale and promotes passive layer formation, including the weld zone.

8.   Non-Destructive Testing (NDT): Weld seam inspected using Eddy Current, Ultrasonic Testing, and optional Radiographic Testing (RT) .

9.   Ferrite Content Measurement: Verification of weld and base metal phase balance (typically 35–65% ferrite).

10.Final Inspection & Marking: Complete dimensional check, visual inspection, and traceable marking.

This controlled process guarantees a sound weld seam, excellent dimensional accuracy, balanced duplex microstructure, and superior corrosion resistance for every batch of Womic Steel’s Duplex 2205 Welded Pipe.

Outside Diameter: 6mm – 1219mm (1/4″ – 48″)

Wall Thickness: 0.5mm – 50mm (SCH 5S – SCH XXS)

Length: Up to 12m (fixed or random); longer lengths available upon request.

Tolerances: According to ASTM A999 / EN ISO 1127 (with additional duplex-specific requirements for straightness and ovality)

*(Refer to ANSI B36.19 / B36.10 dimension tables for detailed schedule matching)*

Womic Steel offers a wide range of surface finishes to meet various industrial, sanitary, and marine applications.

Each S31803 / S32205 pipe surface is inspected for uniform appearance, absence of pits, and consistent finish quality.

Every duplex stainless steel pipe undergoes comprehensive inspection in accordance with ASTM, EN, and GB standards, including duplex-specific tests, to guarantee reliability and performance:

Visual & Dimensional Inspection: Surface, roundness, thickness, and straightness checked.

Hydrostatic Pressure Test: 100% tested for leakage and pressure resistance.

Eddy Current Test (ECT) : Detects surface and sub-surface imperfections.

Ultrasonic Test (UT) : Ensures internal integrity of the pipe wall and weld seam (for welded pipe).

Positive Material Identification (PMI) : Confirms correct chemical grade.

Intergranular Corrosion Test (IGC) : Validates resistance to sensitization (per ASTM A262).

Ferrite Content Measurement: Critical test using magnetic induction or metallographic methods (typically 35–65% ferrite requirement).

Microstructure Examination: Verification of balanced dual-phase structure, absence of intermetallic phases (sigma, chi).

Hardness & Tensile Testing: Confirms mechanical compliance (yield strength ≥450 MPa is key).

Charpy Impact Testing (optional, often required for offshore): Verifies low-temperature toughness at -40°C or -46°C.

Corrosion Testing (optional): Pitting resistance test (e.g., ASTM G48 Method A or C).

Surface Roughness and Cleanliness Check: For sanitary or polished tubes.

Third-Party Inspection (SGS / BV / DNV / TUV): Available upon customer request.

These extensive tests ensure that every S31803 / S32205 Duplex Stainless Steel Pipe from Womic Steel meets the highest international standards for reliability, corrosion resistance, and longevity.

Duplex 2205 stainless steel pipe is ideal for a wide variety of industries where high strength and corrosion resistance are required:

Each duplex stainless steel pipe is securely packed and clearly labeled to ensure safe and efficient transport worldwide.

General packaging for local truck transport:
Bundle packing with woven fabric, iron strip bundle, plastic cap on both ends.

Hexagonal packaging:
Bundle packing with woven fabric, iron strip bundle, plastic cap on two ends.

Packaging for welded pipe in medium and large sizes:
Wrapped with woven fabric by automatic packaging for export sea-worthy transport.

Packaging for medium and large size welded pipes for export:
Wooden or steel crate packaging for export sea-worthy transport.

General packaging for products to be exported:
Wooden box for export sea-worthy transport.

Packaging for precision tubes and heat exchanger tubes:
Wooden box for both local truck and export sea-worthy transport.

1. Direct cooperation with global shipowners ensures the most competitive freight rates.

2. Professional loading and securing teams guarantee damage-free shipment, especially for long-length pipes.

3. Efficient document preparation (including EN 10204 3.1 certificates, NORSOK M-630 documentation) minimizing customs delays.

4. Rapid delivery time — standard sizes of duplex 2205 maintained in ready stock.

5. Continuous cargo tracking and after-sales follow-up to ensure smooth arrival at destination.

6. Why Choose Womic Steel’s S31803 / S32205 Duplex Stainless Steel Pipe

Womic Steel is a trusted manufacturer and exporter specializing in duplex stainless steel pipes, committed to delivering premium quality and professional service.

Strict quality control under ISO 9001 and PED 2014/68/EU certification.

Duplex-specific expertise — experienced technicians trained in phase balance control and duplex welding.

Modern production lines including cold pilger mills and automatic TIG welding lines.

Complete testing, inspection, and documentation support — including ferrite measurement and NORSOK compliance.

Flexible customization — special diameters, wall thicknesses, lengths, and surface finishes.

Fast production cycle and reliable global shipping to all major ports (Houston, Rotterdam, Singapore, Shanghai, Dubai, etc.).

Direct mill pricing with no middlemen — cost-effective duplex solutions.

For inquiries, technical support, or to request a quotation for your specific clad pipe requirements, please contact us:

Website: www.womicstainless.com

E‑mail: info@womicstainless.com

Tel / WhatsApp / WeChat:

Victor: +86 15575100681

Jack: +86 18390957568

Womic Steel – Your reliable partner for high‑quality stainless steel seamless pipes, metallurgically bonded clad tubes, and custom solutions for corrosion‑resistant applications.