Duplex 2205 (UNS S31803 / S32205): Round Bars, Seamless Tubes & Plates — Technical Data Sheet

Quick Answer: What Is Duplex 2205?

Duplex 2205 (UNS S31803 / S32205) (UNS S31803 / S32205 / W.Nr. 1.4462) is a premier ferritic-austenitic duplex stainless steel formulated for service environments demanding high mechanical strength and exceptional corrosion resistance. Its high performance stems from the a balanced dual-phase microstructure strengthened by chromium (22–23%), molybdenum (3.0–3.5%), and nitrogen (0.14–0.20%) within its stable approximately 50% ferrite and 50% austenite matrix. It is supplied in the solution-annealed condition; excessive heat input during welding must be avoided to preserve phase balance. Operating efficiently from approximately -50°C up to a maximum of about 300°C (570°F) for general service, Duplex 2205 is widely utilized in offshore topside, seawater systems, chemical tankers, and high-pressure pipelines.

Product Overview

At the atomic level, its a两相 mixture of body-centered cubic (BCC) ferrite and face-centered cubic (FCC) austenite, giving high strength and toughness. Its primary advantage is roughly double the yield strength of 304/316 stainless steels with vastly superior chloride pitting and stress-corrosion-cracking resistance, which yields high chromium, molybdenum, and nitrogen content produce a PREN (Pitting Resistance Equivalent Number) of approximately 35, far exceeding 316L.

Shanghai Hangbo Alloy Group Co., Ltd., established in 2012, stands as a top-tier global manufacturer and supplier of Duplex 2205. Operating under a certified ISO 9001:2015 quality management system, we command an export network covering 50+ countries. Our portfolio contains high-precision centerless ground round bars, heavy industrial plates, and high-pressure seamless tubing engineered for critical industrial applications. By managing carbon distribution and grain refinement during melting and forging, we ensure our material provides robust structural performance under severe stress. Every order comes with 100% material traceability and certified documentation, ensuring compliance with strict global engineering standards.

Executive Standards

Shanghai Hangbo Alloy Group Co., Ltd. manufactures Duplex 2205 in strict compliance with international technical specifications:

Note: Shanghai Hangbo executes 100% confirmation of chemical compliance using Optical Emission Spectroscopy (OES) for every melt lot.

Chemical Composition

The corrosion-resistant profile of Duplex 2205 depends on its exact chemical balance. Chromium ensures high-temperature oxidation resistance, while molybdenum safeguards against localized pitting in chloride environments.

Mechanical Properties

Duplex 2205 delivers excellent design allowable stresses. The data below outlines typical properties for annealed stock.

Room-Temperature Mechanical Properties

High-Temperature Performance: Strength Retention Analysis

Duplex 2205 retains remarkable mechanical properties under thermal stress, establishing its credentials as a critical superalloy:

How Duplex 2205 Is Produced

Round Bar & Forging

• 1. Electric Arc + AOD / VOD Refining: precise control of C, N, and S.
• 2. Hot Forging / Rolling: worked to refine the duplex phase balance.
• 3. Solution Annealing: 1020–1100°C followed by rapid cooling to retain 50/50 ferrite-austenite.
• 4. Precision Grinding: bars ground to h8/h9 tolerances.

Seamless Tube & Pipe

• 1. Billet Piercing & Extrusion: hollows produced from forged rounds.
• 2. Cold Drawing / Pilgering: precise wall-thickness control.
• 3. Solution Annealing: rapid cooling to preserve phase balance.
• 4. Defect Testing: hydrostatic and Eddy Current testing per ASTM standards.

Sheet, Plate & Strip

• 1. Hot Rolling: controlled reduction.
• 2. Cold Rolling: ±0.05 mm gauge control.
• 3. Solution Annealing: rapid quench.
• 4. Pickling: nitric-hydrofluoric bath restores passive surface.

Industry Applications: Solving Engineering Challenges

Offshore & Marine

2205 is widely used for seawater piping, risers, topside process systems, and subsea manifolds where chloride SCC of 316L is a concern.

Chemical & Petrochemical

Used for reactors, heat exchangers, and storage tanks handling aggressive chloride-containing process streams.

Oil & Gas

High-pressure pipelines, manifolds, and downhole completion equipment benefit from its high strength and sour-gas resistance.

Water Treatment

Desalination plant piping and brine handling systems exploit its seawater corrosion resistance.

Quality Assurance: 7-Stage Zero-Defect Inspection Protocol

Shanghai Hangbo Alloy Group Co., Ltd. deploys an intensive inspection matrix to support a zero-defect mandate across all production lines:

• 1. Chemical verification: OES analysis on every melt batch alongside handheld PMI validation on finished products ensures composition parameters match executive limits.
• 2. Ultrasonic Testing (UT): Performed per ASTM A388 standards across all bars and plates to confirm the absence of inner voids, seams, or gas inclusions.
• 3. Eddy Current Testing (ET): Applied 100% to tubes following ASTM E309 protocols to check surface and sub-surface continuity.
• 4. Hydrostatic Pressure Verification: Tubes undergo hydrostatic tests up to 10,000 PSI to verify wall integrity under high-pressure parameters.
• 5. Mechanical Destructive Testing: Tensile, offset yield, elongation, and Brinell hardness examinations are executed per heat lot to verify strength criteria.
• 6. Dimensional Metrology Check: Digital calipers and computerized laser sensors measure geometry, guaranteeing all diameter, wall, and length tolerances match orders.
• 7. Visual and Microstructure Audit: Surface quality checks are paired with metallographic microscope tests to evaluate grain size (ASTM E112) and phase homogeneity.

All items leave our facilities accompanied by ISO 9001:2015 certification and EN 10204 3.1 Mill Test Certificates. Third-party inspection options through SGS, TUV, or Bureau Veritas (BV) are organized upon customer request.

Frequently asked questions