Product Highlights

• Economical dual-phase 2205 duplex seamless hollow bar, UNS S32205 / S31803, EN 1.4462, compliant with ASTM A789 / A790 seamless tube standards
• Balanced 50/50 austenite-ferrite dual microstructure, yield strength nearly double of 304 / 316L austenitic steel
• Superior resistance to chloride pitting, crevice corrosion and chloride stress corrosion cracking (SCC)
• High molybdenum & nitrogen composition delivers excellent performance in seawater, brine and sour H₂S media
• Low carbon design minimizes intergranular corrosion after welding, no mandatory post-weld heat treatment
• Seamless extrusion forming eliminates internal weld defects, stable wall thickness uniformity
• Custom OD, ID, wall thickness & full CNC boring, turning, threading machining per CAD drawings
• Cost-effective high-strength alternative for marine, desalination & oil gas corrosive tubular components

Product Overview

This series of 2205 duplex seamless hollow bars are manufactured via hot extrusion + cold drawing forming process. After strict 1020–1100℃ solution annealing followed by rapid water quenching, the material forms uniform dual-phase austenite-ferrite grain structure without harmful intermetallic precipitates.

2205 is the most widely used standard duplex stainless steel grade. It combines high mechanical strength and outstanding chloride corrosion resistance, filling the performance gap between ordinary austenitic stainless steel and expensive super duplex grades. Seamless hollow bar blanks save massive solid bar boring workload, widely machined into heat exchanger tubes, offshore tubular fittings, desalination pipeline sleeves and sour gas downhole components for marine, chemical, pulp & paper and oil & gas industries.

Material Grade Characteristics – 2205 Duplex (S32205 / 1.4462)

• Balanced two-phase stainless steel with 22Cr-5.5Ni-3Mo-N alloy formula, PREN value ≥35
• Double yield strength compared to 316L, allows thinner wall design to reduce equipment weight & cost
• Excellent anti-SCC & anti-erosion performance under flowing seawater and high-chloride brine
• Good sulfide stress cracking (SSC) resistance compliant with NACE MR0175 for sour service
• Stable metallurgy after welding, only low heat input welding required without post annealing
• Limited continuous service temperature below 300℃ to avoid brittle sigma phase precipitation

Chemical Composition (Weight %)

Mechanical Properties (Solution Annealed & Water Quenched, ASTM A790)

Related Material Grades

• Duplex Stainless Steel: 2205, 2507, S32750, S32760, F51, F55, F60
• Austenitic Stainless Steel: 304, 316L, 321, 347, 904L, 254SMo
• PH Stainless Steel: 17-4PH, 15-5PH, 17-7PH
• Nickel Alloys: Monel 400, Incoloy 825, Inconel 625 / 690 / X750, Hastelloy C4 / C276
• Alloy & Carbon Steel: 4140, 4340, F22, F91, A105, A516 Gr.70

Key Advantages

1. Double Yield Strength vs Austenitic Steel

   450MPa minimum yield strength enables thinner wall hollow design, reduces raw material consumption and overall equipment weight.

2. Outstanding Chloride Corrosion Resistance

   High PREN index resists seawater pitting, crevice and stress cracking, far superior to 316L in marine & desalination environments.

3. Sour Gas SSC Compliant Performance

   Passes NACE standard test, reliable for H₂S-containing oil & gas downhole tubular service.

4. Stable Welded Metallurgy

   Low carbon formula prevents intergranular corrosion; no post heat treatment needed after welding with controlled heat input.

5. Seamless Hollow Cost Saving

   Ready extruded hollow blank eliminates deep boring on solid bar, shortens CNC processing cycle and lowers machining cost.

Typical Applications

• Seawater desalination heat exchanger seamless tubes & pipeline hollow fittings
• Offshore platform seawater cooling system tubular components
• Oil & gas sour well gathering pipelines and downhole hollow blanks
• Pulp & paper bleach tower circulation tubular parts
• Chemical plant brine & chloride medium heat exchange hollow bars
• Marine ship ballast water pipeline and pump sleeve blanks
• Waste water treatment high-chloride corrosion resistant tubular stock

Processing Service

We provide integrated hot extrusion & cold drawing production, full precision machining per customer CAD/PDF drawings:

• Fixed-length cutting, facing, chamfering, inner & outer diameter turning
• CNC Boring, Milling, Drilling, Threading, Grooving, Flange machining
• Solution annealing + water quenching heat treatment customization
• Surface pickling, internal/external grinding & passivation finishing

We supply 2205 duplex hollow blanks, heat exchanger tubes, valve sleeves and tubular fittings for marine, chemical and energy global clients.

Quality Assurance

• Eddy Current + Dual UT testing to detect seamless tube internal wall defects
• Tensile & hardness full batch mechanical performance inspection
• High-precision calipers to control OD / ID / wall thickness tolerance
• Spectrometer full spectrum chemical composition analysis per heat lot
• Metallographic microscope dual-phase microstructure ratio inspection

Mill Test Certificate EN 10204 3.1 can be issued and attached with shipment documents.

Packing & Delivery