Womic Stainless Steel Co., Ltd
High Strength (≥450 MPa Yield): Approximately twice the yield strength of 304/304L and 316/316L, allowing for thinner and lighter flat bar sections with same load capacity.
Superior Chloride SCC Resistance: Outstanding resistance to chloride-induced stress corrosion cracking, performing reliably in high-chlorine environments where 304L and 316L fail.
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.
Balanced Dual-Phase Microstructure: Approximately 50% ferrite and 50% austenite provides excellent combination of mechanical properties and corrosion resistance.
Good Weldability: Maintains balanced ferrite/austenite ratio in the weld zone with proper welding procedures using matching filler metals (ER2209).
High Resistance to Erosion and Wear: Higher hardness and strength provide improved resistance to erosion and wear compared to austenitic grades.
Excellent Impact Toughness: Maintains good impact toughness down to -40°C, suitable for cold climate and offshore applications.
Low Thermal Expansion: Coefficient of thermal expansion (13.5 μm/m·K) lower than austenitic grades, reducing thermal stress in assemblies.
Square Edges: Precision-rolled square edges for accurate fitting and welding.
International Certifications: Flat bars can be certified by ABS, BV, DNV, LR, GL, RINA, CCS, KR, and NK, and comply with NORSOK M-630 standards.
|
Standard |
Description |
Corresponding Duplex Grade |
|
ASTM A276 / A479 |
Standard specification for stainless steel bars and shapes |
S31803 / S32205 |
|
ASTM A484 |
General requirements for stainless steel bars and shapes |
S31803 / S32205 |
|
EN 10058 |
European standard for hot-rolled flat steel bars |
1.4462 (X2CrNiMoN22-5-3) |
|
EN 10088-3 |
European standard for stainless steel bars for general purposes |
1.4462 |
|
JIS G4303 |
Japanese standard for stainless steel bars |
SUS329J3L |
|
JIS G4318 |
Japanese standard for cold-finished stainless steel bars |
SUS329J3L |
|
GB/T 1220 |
Chinese standard for stainless steel bars |
022Cr22Ni5Mo3N |
|
NORSOK M-630 |
Offshore material standard |
S31803 / S32205 |
|
NACE MR0175 / ISO 15156 |
Sour service compliance |
S31803 / S32205 |
|
Element |
C |
Mn |
P |
S |
Si |
Cr |
Ni |
Mo |
N |
|
S31803 |
≤0.030 |
≤2.00 |
≤0.030 |
≤0.020 |
≤1.00 |
21.0–23.0 |
4.5–6.5 |
2.5–3.5 |
0.08–0.20 |
|
S32205 |
≤0.030 |
≤2.00 |
≤0.030 |
≤0.020 |
≤1.00 |
22.0–23.0 |
4.5–6.5 |
3.0–3.5 |
0.14–0.20 |
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 PRE (Pitting Resistance Equivalent) for S32205 is ≥35, compared to ≤26 for 316L.
Comparison of Strength and Corrosion Resistance:
|
Grade |
Yield Strength (MPa) |
PRE |
Seawater Suitability |
Chloride SCC Resistance |
|
304/304L |
170-205 |
18-19 |
Poor |
Poor |
|
316/316L |
170-205 |
24-26 |
Limited |
Poor |
|
Duplex 2205 |
≥450 |
34-35 |
Good to Excellent |
Excellent |
|
Super Duplex 2507 |
≥550 |
42-45 |
Excellent |
Excellent |
|
Property |
Unit |
S31803 / S32205 (Solution Annealed + Quenched) |
|
Tensile Strength |
MPa |
≥620 |
|
Yield Strength (0.2% offset) |
MPa |
≥450 |
|
Elongation |
% |
≥25 |
|
Hardness (Brinell) |
HBW |
≤290 |
|
Hardness (Rockwell C) |
HRC |
≤30 |
|
Density |
g/cm³ |
7.80 |
|
Melting Range |
°C |
1350–1400 |
|
Modulus of Elasticity |
GPa |
200 |
|
Thermal Conductivity (20°C) |
W/m·K |
19.0 |
|
Coefficient of Thermal Expansion (20–100°C) |
μm/m·K |
13.5 |
Impact Toughness (Charpy V-Notch, typical at -40°C):
Longitudinal: ≥ 60 J (typical)
Heat Treatment Condition:
Duplex 2205 stainless steel flat bars are solution annealed at
1040–1120°C followed by rapid cooling (water quenching) .
This heat treatment restores the balanced 40–60% ferrite / 40–60% austenite
microstructure, dissolves unwanted intermetallic phases, relieves internal
stresses, and ensures maximum corrosion resistance.
Critical Note: Unlike austenitic grades, Duplex 2205 requires water quenching after solution annealing. Air cooling may result in intermetallic phase precipitation, reducing corrosion resistance and toughness.
Delivery Condition Options:
l Black (Hot-Rolled): As-rolled with mill scale – for general structural applications
l Pickled: Acid-treated, oxide-free surface – for welding and fabrication
l Grit Blasted: Matte, uniform surface texture – for paint adhesion
Standard Thickness Ranges:
|
Thickness (mm) |
Width Range (mm) |
Tolerance (mm) |
|
5 – 10 |
20 – 150 |
±0.3 |
|
10 – 20 |
30 – 200 |
±0.4 |
|
20 – 30 |
40 – 250 |
±0.5 |
|
30 – 50 |
50 – 300 |
±0.7 |
Standard Width Ranges:
|
Width (mm) |
Tolerance (mm) |
|
20 – 50 |
±0.5 |
|
50 – 100 |
±0.8 |
|
100 – 200 |
±1.0 |
|
200 – 300 |
±1.5 |
Standard Lengths:
l 3000mm (3 meters)
l 6000mm (6 meters)
l Custom lengths available upon request
Straightness Tolerances:
l Standard: 2mm per meter
l Precision: 1mm per meter (upon request)
|
Dimensions (mm) |
Weight (kg/m) |
Dimensions (mm) |
Weight (kg/m) |
|
20 x 5 |
0.78 |
60 x 10 |
4.68 |
|
25 x 5 |
0.98 |
60 x 12 |
5.62 |
|
25 x 6 |
1.17 |
65 x 8 |
4.06 |
|
30 x 5 |
1.17 |
65 x 10 |
5.07 |
|
30 x 6 |
1.40 |
70 x 8 |
4.37 |
|
30 x 8 |
1.87 |
70 x 10 |
5.46 |
|
40 x 5 |
1.56 |
75 x 10 |
5.85 |
|
40 x 6 |
1.87 |
80 x 8 |
4.99 |
|
40 x 8 |
2.50 |
80 x 10 |
6.24 |
|
40 x 10 |
3.12 |
80 x 12 |
7.49 |
|
50 x 6 |
2.34 |
100 x 8 |
6.24 |
|
50 x 8 |
3.12 |
100 x 10 |
7.80 |
|
50 x 10 |
3.90 |
100 x 12 |
9.36 |
|
50 x 12 |
4.68 |
100 x 15 |
11.70 |
|
60 x 6 |
2.81 |
120 x 10 |
9.36 |
|
60 x 8 |
3.74 |
120 x 12 |
11.23 |
*Formula: Weight (kg/m) = Width (mm) × Thickness (mm) × 0.00780*
|
Surface Finish |
Code |
Description |
Typical Offshore/Marine Applications |
|
Black (Hot-Rolled) |
HR |
As-rolled with mill scale |
General structural, embedded applications |
|
Pickled |
P |
Acid-treated, oxide-free, matte finish |
Welded fabrications, offshore supports |
|
Grit Blasted |
GB |
Matte, uniform surface texture |
Topside offshore structures requiring paint |
|
Passivated |
PA |
Chemically treated for enhanced corrosion resistance |
Critical marine and chemical service |
Chemical Analysis: PMI verification for Cr, Ni, Mo, N (critical for duplex performance).
Ferrite Content Measurement: Magnetic induction method – requirement 35–65% ferrite documented.
Microstructure Examination: Verification of balanced dual-phase structure, absence of intermetallic phases.
Mechanical Testing: Tensile (≥620 MPa), yield (≥450 MPa), elongation (≥25%), hardness (≤290 HBW).
Charpy Impact Testing: -40°C upon request.
Dimensional Inspection: Thickness, width, length, straightness, squareness.
Surface Inspection: Visual check for defects, cracks, seams.
Ultrasonic Testing (UT): Upon request.
Pitting Corrosion Test: ASTM G48 upon request.
Third-Party Inspection: SGS, BV, DNV, TUV, LR, ABS available.
Offshore Platforms: Equipment support brackets, pipe rack supports, module framework stiffeners, deck grating supports, helideck structures (ABS/BV/DNV/LR certified, NORSOK M-630 compliant).
Marine Structures: Shipbuilding stiffeners, boat trailer components, dock hardware, seawater intake grill supports, ballast tank structures.
Seawater Systems: Intake screen supports, outfall diffuser brackets, cooling water pipe supports, seawater pump bases.
Desalination Plants: Brine line supports, evaporator structural brackets, piping rack stiffeners, equipment frames.
Chemical Plant Supports: Equipment mounting brackets, agitator supports, reactor platform structures, tank stiffeners for chloride service.
Flue Gas Desulfurization (FGD): Scrubber support brackets, absorber tower stiffeners, ductwork supports.
Pressure Vessel Supports: Vessel skirt stiffeners, support lug bases, platform brackets for chloride service.
Bridge Components (Marine/Coastal): Bridge stiffeners, handrail brackets, access walkway supports.
Port & Harbor Facilities: Crane rail supports, fender brackets, pier framing stiffeners, loading platform brackets.
1. Why choose Duplex 2205 over 316L
for flat bar applications in marine environments?
Duplex 2205 offers approximately twice the yield strength (≥450 MPa vs ≥170
MPa) and superior chloride SCC resistance. For offshore platform supports,
seawater system brackets, and chemical plant structures, Duplex 2205 provides
reliable long-term performance.
2. What is the difference between
S31803 and S32205 Duplex 2205 flat bars?
S32205 has tighter composition controls (higher Cr, Mo, and N), providing
enhanced corrosion resistance (PRE ≥35 vs ≥34). S32205 is generally preferred
for new offshore construction and sour service applications.
3. Can Duplex 2205 flat bars be
welded?
Yes, but require proper welding procedures with low heat input and N₂ shielding
gas. Matching filler metal ER2209 is recommended. Post-weld heat treatment
generally not required.
4. What is the maximum service
temperature for Duplex 2205 flat bars?
250°C (482°F) for continuous service in chloride environments; 300°C (572°F)
for non-chloride service. Above 300°C, risk of sigma phase embrittlement.
5. Are Duplex 2205 flat bars
suitable for sour service (H₂S environments)?
Yes, Duplex 2205 is NACE MR0175 compliant for sour service applications.
Hardness is controlled at ≤32 HRC. HIC and SSC test reports available upon
request.
6. What surface finish is
recommended for offshore topside structures?
Grit blasted finish is recommended for offshore topside structures requiring
paint adhesion. Pickled finish is suitable for most seawater immersion
applications.
High-Strength Material: 2.2-2.6x stronger than 316L – lighter sections for same load
Marine & Offshore Certified: ABS, BV, DNV, LR certifications available
NORSOK M-630 Qualified: Complete documentation for offshore projects
NACE MR0175 Compliant: Full sour service certification
Ferrite Controlled: 35-65% ferrite documented per heat
Square Edges: Precision-rolled for accurate fabrication
Full Traceability: Heat number on each bundle – traceable to raw material
Complete Size Range: Thickness from 5mm to 50mm – standard and custom sizes
Global Delivery: Exported to major offshore, marine, and subsea projects worldwide
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 products, precision machined components, and custom solutions for corrosion‑resistant applications.
Stock Examples (Duplex 2205 Stainless Steel Flat Bars – Pickled Finish – Offshore Grade):
|
Dimensions (mm) |
Length |
Weight (kg/m) |
Typical Application |
|
30 x 6 |
6000mm |
1.40 |
Light equipment brackets |
|
40 x 8 |
6000mm |
2.50 |
Pipe rack supports |
|
50 x 10 |
6000mm |
3.90 |
Module framework stiffeners |
|
60 x 10 |
6000mm |
4.68 |
Platform support brackets |
|
80 x 10 |
6000mm |
6.24 |
Deck grating supports |
|
100 x 12 |
6000mm |
9.36 |
Heavy offshore structures |
|
120 x 12 |
6000mm |
11.23 |
Equipment mounting bases |
Stock Examples (Duplex 2205 Stainless Steel Flat Bars – Grit Blasted – Topside Paint Grade):
|
Length |
Weight (kg/m) |
Typical Application |
|
|
50 x 8 |
6000mm |
3.12 |
Handrail brackets |
|
65 x 10 |
6000mm |
5.07 |
Stair stringer supports |
|
75 x 10 |
6000mm |
5.85 |
Walkway supports |
|
100 x 10 |
6000mm |
7.80 |
Helideck structures |
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