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- SS SMLS PIPE S31803 ASTM A790
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- SS SMLS PIPE TP304 ASTM A312
S31803 Duplex Stainless Steel Pipe from China | Reliable Suppliers & Factory for Immediate Shipment
Introduction
ASTM A790/A790M S31803 duplex stainless steel pipes combine austenitic and ferritic microstructures, delivering twice the strength of 316L with exceptional resistance to chloride-induced stress corrosion cracking (SCC). Ideal for harsh offshore, chemical, and marine applications, this alloy balances cost-efficiency with premium performance.
Key Features
Dual-Phase Strength
Yield strength ≥450 MPa, nearly double conventional stainless steels (e.g., 304/316), reducing wall thickness and material costs.
Enhanced Corrosion Resistance
21%-23% Cr, 2.5%-3.5% Mo, and 4.5%-6.5% Ni combat pitting/crevice corrosion in seawater, acids, and sour gas (H₂S) environments (PREN ≥35).
Thermal Stability
Performs reliably from -50°C to 300°C (-58°F to 572°F), suitable for subsea and high-pressure systems.
Material Specification
Standard
ASTM A790/A790M
Outside Diameter (O.D.)
1/8" NB TO 32" NB (10.29MM-812.80MM) (Customization Available)
Wall Thickness (W.T.)
SCH 10S, SCH 40S, SCH 80S, SCH160, SCH XXS (Customization Available)
Applications
- Oil & Gas Pipelines (Including Sour Service)
- Chemical & Petrochemical Processing
- Desalination & Water Treatment Plants
- Marine & Offshore Structures
- Power Plants (Including Flue Gas Desulfurization)
- Pulp & Paper Industry
- Heat Exchangers & Condensers
Ends
Plain End, Beveled End, Threaded
Processing
Cut-to-length, Polishing
Inspection
- 100% PMI (Positive Material Identification) Tested
- EN 10204 3.1/3.2 Mill Test Certificate
- Third-Party Inspection Accepted (SGS, BV, TUV, etc.)
- Ultrasonic Testing (UT) / Eddy Current Testing (ECT) Available
- Hardness, Tensile, and Impact Testing as per ASTM Standards
Delivery Condition
Cold Drawn, Annealed and Pickled / Polished / Bright Annealed / Sand blasting / Shot Blasting
Marking
All SS SMLS Pipes are marked as follows: Standard, Grade, OD, Thickness, Length, Heat No. (Or as per the customer’s request)
Packing
Packed in Wooden Boxes, plywood cases, Steel Strips Bundled, or as per Customers Requests
Specials
Sizes and Specifications other than above can be customized on request.
Specification Parameters
S31803 Chemical Composition
| HEAT NO. | CHEMICAL COMPOSITION (%) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| C | Mn | P | S | Si | Ni | Cr | Mo | N | ||
| STAND. | MIN. | - | - | - | - | - | 4.50 | 21.00 | 2.50 | 0.08 |
| MAX. | 0.03 | 2.00 | 0.03 | 0.020 | 1.00 | 6.50 | 23.00 | 3.50 | 0.20 | |
S31803 Mechanical Properties
| Mechanical Properties | |||||
|---|---|---|---|---|---|
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| HRW | HRC | ||||
| S31803 | 620 | 450 | 25 | 290 | 30 |
Equivalent Grades - (ASTM A790/A790M S31803 Equivalent Grades)
| ASTM A790/A790M S31803 (UNS S31803) Equivalent Grades | ||||||
|---|---|---|---|---|---|---|
| ISO | EN (Europe) | DIN (Germany) | JIS (Japan) | GB (China) | UNS (USA) | AISI/SAE |
| X2CrNiMoN22-5-3 (ISO 15510) |
1.4462 (EN 10088-2) |
X2CrNiMoN22-5-3 (DIN 17440) |
SUS 329J3L (JIS G3463) |
022Cr22Ni5Mo3N (GB/T 21833) |
S31803 | Duplex 2205 (Commercial Name) |
ASTM A312/A312M Standard Cold Machining size Deviation Permitted
| ASTM A312/A312M-09 Standard Permitted Tolerance of WT and OD | |||||
|---|---|---|---|---|---|
| Nominal Outside Diameter | Allowable deviation | Nominal wall thickness | Allowable deviation | ||
| 1/8”—1 1/2“ | (10.29—48.26) | +0.4 -0.8 | 1/8”—1 1/2“ | (10.29-73.03) all of t | +20 -12.5 |
| >1 1/2“—4” | (48.26—114.3) | ±0.8 | 3“—18” | (88.9-457.2) t/D=5% | +22.5 -12.5 |
| >4”—8" | (114.3—219.08) | +1.6 -0.8 | 3“—18” | (88.9-457.2) t/D>5% | +15 -12.5 |
| >8“—18" | (219.08—457.2) | +2.4 -0.8 | ≥20" | =508 t of wld pipe | +17.5 -12.5 |
| >18”—26“ | (457.2—660.4) | +3.2 -0.8 | ≥20" | =508 t/D=5% | +22.5 -12.5 |
| >26”—34” | (660.4—863.6) | +4.0 -0.8 | ≥20" | =508 t/D>5% | +15 -12.5 |
| >34“—48" | (863.6—1219.2) | +4.8 -0.8 | - | - | - |
| Thin wall pipe (t/D=3%) ovality condition: Any cross section in a steel pipe Dmax Dmin=1.5% nominal, and (Dmax Dmin)/ 2 conforms to the stipulated diameter tolerance range. | |||||
Comparison Table Of American Standard Dimensions - (ANSI B36.19 & ANSI B36.10) (Refers to ASTM A312)
| OD DN | IN | OD MM | ANSI B36.19 | ANSI B36.10 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal diameter in inches | ||||||||||||||||||||
| 5s | 10s | Sched.40s | Sched.40 | Sched.80s | Sched.80 | 10 | 20 | 30 | Standard | |||||||||||
| mm | Kg/m | mm | Kg/m | mm | Kg/m | mm | mm | Kg/m | mm | mm | Kg/m | mm | Kg/m | mm | Kg/m | mm | Kg/m | |||
| 6 | 1/8" | 10.29 | - | - | 1.24 | 0.281 | 1.73 | 371 | 1.73 | 2.41 | 0.467 | 2.41 | - | - | - | - | - | - | 1.73 | 0.371 |
| 8 | 1/4" | 13.72 | - | - | 1.65 | 0.499 | 2.24 | 0.644 | 2 | 3.02 | 0.809 | 3.02 | - | - | - | - | - | - | 2.24 | 0.644 |
| 10 | 3/8" | 17.14 | - | - | 1.65 | 0.64 | 2.31 | 0.858 | 2.31 | 3.2 | 1.118 | 3.2 | - | - | - | - | - | - | 2.31 | 0.858 |
| 15 | 1/2" | 21.34 | 1.65 | 0.814 | 2.11 | 1.016 | 2.77 | 1.26 | 2.77 | 3.73 | 1.62 | 3.73 | - | - | - | - | - | - | 2.77 | 1.26 |
| 20 | 3/4" | 26.67 | 1.65 | 1.034 | 2.11 | 1.298 | 2.87 | 1.68 | 2.87 | 3.91 | 2.19 | 3.91 | - | - | - | - | - | - | 2.87 | 1.68 |
| 25 | 1" | 33.4 | 1.65 | 1.312 | 2.77 | 2.125 | 3.38 | 2.5 | 3.38 | 4.55 | 3.23 | 4.55 | - | - | - | - | - | - | 3.36 | 2.5 |
| 32 | 1 1/4" | 42.16 | 1.65 | 1.674 | 2.77 | 2.732 | 3.56 | 3.38 | 3.56 | 4.85 | 4.46 | 4.85 | - | - | - | - | - | - | 3.56 | 3.38 |
| 40 | 1 1/2" | 48.26 | 1.65 | 1.926 | 2.77 | 3.155 | 3.68 | 4.05 | 3.68 | 5.08 | 5.4 | 5.08 | - | - | - | - | - | - | 3.68 | 4.05 |
| 50 | 2" | 60.32 | 1.65 | 2.424 | 2.77 | 3.992 | 3.91 | 5.43 | 3.91 | 5.54 | 7.47 | 5.54 | - | - | - | - | - | - | 3.91 | 5.43 |
| 65 | 2 1/2" | 73.02 | 2.11 | 3.747 | 3.05 | 5.345 | 5.16 | 8.62 | 5.16 | 7.01 | 11.4 | 7.01 | - | - | - | - | - | - | 5.16 | 8.62 |
| 80 | 3" | 88.9 | 2.11 | 4.585 | 3.05 | 6.557 | 5.49 | 11.28 | 5.49 | 7.62 | 15.25 | 7.62 | - | - | - | - | - | - | 5.49 | 11.28 |
| 90 | 3 1/2" | 101.6 | 2.11 | 5.272 | 3.05 | 7.526 | 5.74 | 13.56 | 5.74 | 8.08 | 18.62 | 8.08 | - | - | - | - | - | - | 5.74 | 13.56 |
| 100 | 4" | 114.3 | 2.11 | 5.945 | 3.05 | 8.496 | 6.02 | 16.06 | 6.02 | 8.56 | 22.29 | 8.56 | - | - | - | - | - | - | 6.02 | 16.06 |
| 125 | 5" | 141.3 | 2.77 | 9.639 | 3.4 | 11.74 | 6.55 | 21.76 | 6.55 | 9.52 | 30.92 | 9.52 | - | - | - | - | - | - | 6.55 | 21.76 |
| 150 | 6" | 168.28 | 2.77 | 11.514 | 3.4 | 14.037 | 7.11 | 28.23 | 7.11 | 10.97 | 42.52 | 10.97 | - | - | - | - | - | - | 7.11 | 28.23 |
| 200 | 8" | 219.08 | 2.77 | 15.049 | 3.76 | 20.334 | 8.18 | 42.49 | 8.18 | 12.7 | 64.57 | 12.7 | - | - | 6.35 | 33.28 | 7.04 | 36.8 | 8.18 | 42.4 |
| 250 | 10" | 273.05 | 3.4 | 23.028 | 4.19 | 28.29 | 9.27 | 60.24 | 9.27 | 12.7 | 81.46 | 15.09 | - | - | 6.35 | 41.7 | 7.8 | 51 | 9.27 | 60.24 |
| 300 | 12" | 323.85 | 3.96 | 31.806 | 4.57 | 36.633 | 9.52 | 73.76 | 10.31 | 12.7 | 97.36 | 17.48 | - | - | 6.35 | 49.68 | 8.38 | 65.14 | 9.52 | 73.76 |
| 350 | 14" | 355.6 | 3.98 | 34.99 | 4.78 | 42.102 | 9.52 | - | 11.13 | - | - | 19.05 | 6.35 | 54.63 | 7.92 | 67.98 | 9.52 | 81.21 | 9.52 | 81.21 |
| 400 | 16" | 406.4 | 4.19 | 42.35 | 4.78 | 48.22 | 9.52 | - | 12.7 | - | - | 21.44 | 6.35 | 62.58 | 7.92 | 77.9 | 9.52 | 93.13 | 9.52 | 93.18 |
| 450 | 18" | 457.2 | 4.19 | 47.7 | 4.78 | 54.3 | 9.52 | - | 14.27 | - | - | 23.82 | 6.35 | 70.5 | 7.92 | 87.8 | 11.13 | 122.12 | 9.52 | 105.05 |
| 500 | 20" | 508 | 4.77 | 60.32 | 5.54 | 69.766 | 9.52 | - | 15.09 | - | - | 26.19 | 6.35 | 78.47 | 9.52 | 116.97 | 12.7 | 155 | 9.52 | 116.97 |
| 550 | 22" | 558.8 | 4.77 | - | 5.54 | - | 9.52 | - | - | - | - | 28.58 | 6.35 | 86.42 | 9.52 | 128.89 | 12.7 | 170.86 | 9.52 | 128.89 |
| 600 | 24" | 609.6 | 5.54 | 84.1 | 6.35 | 96.215 | 9.52 | - | 17.48 | - | - | 30.96 | 6.35 | 96.215 | 9.52 | 140.8 | 14.7 | 209.54 | 9.52 | 140.81 |
| 650 | 26" | 660.4 | - | - | - | - | 9.52 | - | - | - | - | - | 7.92 | 127.58 | 12.7 | 202.65 | - | - | 9.52 | 152.73 |
| 700 | 28" | 711.2 | - | - | - | - | 9.52 | - | - | - | - | - | 7.92 | 137.52 | 12.7 | 218.54 | 15.88 | 271.94 | 9.52 | 164.65 |
| 750 | 30" | 762 | 6.35 | 120.59 | 7.92 | 147.45 | 9.52 | - | - | - | - | - | 7.92 | 147.45 | 12.7 | 234.44 | 15.88 | 291.81 | 9.52 | 176.57 |
| 800 | 32" | 812 | - | - | - | - | 9.52 | - | 17.48 | - | - | - | 7.92 | 157.39 | 12.7 | 250.33 | 15.88 | 311.67 | 9.52 | 188.5 |
| 850 | 34" | 863.6 | - | - | - | - | 9.52 | - | 17.48 | - | - | - | 7.92 | 167.32 | 12.7 | 266.22 | 15.88 | 331.54 | 9.52 | 200.42 |
| 900 | 36" | 914.4 | - | - | - | - | 9.52 | - | 19.05 | - | - | - | 7.92 | 177.26 | 12.7 | 282.18 | 15.88 | 351.41 | 9.52 | 212.34 |
Frequently Asked Questions (FAQ)
Q:
What are the main advantages of ASTM A790 S31803 duplex stainless steel pipes?
ASTM A790 S31803 duplex pipes combine austenitic and ferritic microstructures, offering yield strength (≥450 MPa) that is nearly double that of conventional 304/316 stainless steels. This allows for reduced wall thickness and material weight, alongside exceptional resistance to chloride-induced stress corrosion cracking (SCC), pitting, and crevice corrosion.
Q:
What is the standard chemical composition of S31803 duplex stainless steel?
According to the specification parameters, S31803 steel is composed of 21.00% to 23.00% Chromium (Cr), 4.50% to 6.50% Nickel (Ni), and 2.50% to 3.50% Molybdenum (Mo) as its key alloying elements, along with a controlled nitrogen content of 0.08% to 0.20% and a low carbon limit of 0.03% max.
Q:
What mechanical properties can be expected from S31803 duplex steel?
S31803 duplex stainless steel features a minimum tensile strength of 620 MPa, a minimum yield strength (0.2% Proof) of 450 MPa, and a minimum elongation of 25% (in 50mm). Its maximum hardness values are 290 HRW and 30 HRC.
Q:
What are the typical industrial applications for S31803 pipes?
These pipes are extensively used in high-demand fields such as Oil & Gas pipelines (including sour service), Chemical & Petrochemical processing, Desalination & Water Treatment plants, Marine & Offshore structures, Power plants (including flue gas desulfurization systems), Pulp & Paper industries, and Heat exchangers/condensers.
Q:
What testing and inspections are performed on S31803 duplex pipes?
Standard quality assurances include 100% PMI (Positive Material Identification) testing, mill test certifications conforming to EN 10204 3.1/3.2, and hardness, tensile, and impact testing according to ASTM standards. Optional testing such as Ultrasonic Testing (UT), Eddy Current Testing (ECT), and third-party inspections (by SGS, BV, TUV, etc.) are also widely accepted.
Q:
What are the equivalent grades of ASTM A790 S31803 across global standards?
S31803 is globally equivalent to X2CrNiMoN22-5-3 (ISO 15510 & DIN 17440), 1.4462 (EN 10088-2), SUS 329J3L (JIS G3463), and 022Cr22Ni5Mo3N (GB/T 21833). It is commercially known as Duplex 2205.