High-Temperature Heat-Resistant 25Cr-20Ni Austenitic Stainless Steel Seamless, Welded & ERW Pipes and Radiant Tubes
Om Export India Pvt Ltd is an internationally recognized manufacturer, stockist, and global supplier of high-temperature Stainless Steel 310 and 310S Pipes and Tubes (ASTM A312 TP310 / TP310S / UNS S31000 / UNS S31008 / Werkstoff 1.4841 / 1.4845). Grade 310 is a high-alloy austenitic stainless steel engineered with 24.0% to 26.0% Chromium and 19.0% to 22.0% Nickel, designed specifically for extreme high-temperature environments. It provides continuous oxidation and scaling resistance in air up to 1100°C–1150°C (2012°F–2102°F) and intermittent cyclic service resistance up to 1035°C (1895°F).
Our complete manufacturing range encompasses cold-drawn precision seamless pipes, automated TIG/plasma fusion-welded pipes, high-frequency ERW lines, and heavy-wall radiant furnace tubes manufactured strictly in accordance with ASTM A312, ASTM A358, ASTM A213, and Indian Boiler Regulations (IBR). Operating with a density of 7.75 g/cm³ (7750 kg/m³) and an ultimate tensile strength exceeding 515 MPa, SS 310/310S provides superior resistance to hot sulfidation, carburization, and thermal fatigue, serving critical installations across petrochemical cracker furnaces, burner pipes, fluidized bed coal combustors, thermal power steam boilers, and kiln recuperators.
| Specification Parameter | Standard Specification / Technical Value |
|---|---|
| Nominal Size Range (Seamless) | 1/8" NB to 24" NB (6.00 mm to 609.6 mm OD) / Up to 1200 NB Custom |
| Nominal Size Range (Welded / ERW / EFW) | 1/8" NB to 48" NB (6.00 mm to 1219.2 mm OD) |
| Wall Thickness & Schedules | 0.30 mm to 50.0 mm (SCH 5S, SCH 10S, SCH 40S/STD, SCH 80S/XS, SCH 160, SCH XXS) |
| Governing Standards | ASTM A312 / ASME SA312, ASTM A213, ASTM A358, ASTM A249, ASTM A376, ASTM A409, ASTM A813, ASTM A814 |
| Manufacturing Methods | Cold Drawn Seamless (CDS), Hot Finished Seamless, High-Frequency Induction ERW, Plasma/TIG Welded, LSAW |
| Heat Treatment & Delivery State | Solution Annealed at 1040°C – 1150°C (1900°F – 2100°F) followed by rapid water quench; Bright Annealed (BA) |
| Standard Lengths | Single Random Length (SRL), Double Random Length (DRL), Custom Cut Lengths up to 26,000 mm (26m) |
| End Configurations & Protection | Plain Square Cut End (PE), Beveled End (BE 30°/37.5° per ASME B16.25), Threaded Ends with Protective Plastic Caps |
| Nominal Pipe Size (NPS) | Outside Diameter (OD mm / in.) | Wall Thickness (WT mm / in.) | Nominal Schedule | Nominal Weight (kg/m) | Nominal Weight (lb/ft) |
|---|---|---|---|---|---|
| 1/2" NB | 21.34 mm (0.840") | 1.65 mm (0.065") | SCH 10S | 0.81 kg/m | 0.54 lb/ft |
| 1/2" NB | 21.34 mm (0.840") | 2.77 mm (0.109") | SCH 40S / STD | 1.29 kg/m | 0.85 lb/ft |
| 1/2" NB | 21.34 mm (0.840") | 3.73 mm (0.147") | SCH 80S / XS | 1.65 kg/m | 1.09 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 1.65 mm (0.065") | SCH 10S | 1.03 kg/m | 0.69 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 2.87 mm (0.113") | SCH 40S / STD | 1.71 kg/m | 1.13 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 3.91 mm (0.154") | SCH 80S / XS | 2.23 kg/m | 1.48 lb/ft |
| 1" NB | 33.40 mm (1.315") | 1.65 mm (0.065") | SCH 5S | 1.31 kg/m | 0.88 lb/ft |
| 1" NB | 33.40 mm (1.315") | 2.77 mm (0.109") | SCH 10S | 2.13 kg/m | 1.43 lb/ft |
| 1" NB | 33.40 mm (1.315") | 3.38 mm (0.133") | SCH 40S / STD | 2.54 kg/m | 1.68 lb/ft |
| 1" NB | 33.40 mm (1.315") | 4.55 mm (0.179") | SCH 80S / XS | 3.29 kg/m | 2.17 lb/ft |
| 1-1/4" NB | 42.16 mm (1.660") | 2.77 mm (0.109") | SCH 10S | 2.73 kg/m | 1.83 lb/ft |
| 1-1/4" NB | 42.16 mm (1.660") | 3.56 mm (0.140") | SCH 40S / STD | 3.44 kg/m | 2.31 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 2.77 mm (0.109") | SCH 10S | 3.16 kg/m | 2.12 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 3.68 mm (0.145") | SCH 40S / STD | 4.11 kg/m | 2.72 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 5.08 mm (0.200") | SCH 80S / XS | 5.49 kg/m | 3.63 lb/ft |
| 2" NB | 60.33 mm (2.375") | 2.77 mm (0.109") | SCH 10S | 3.99 kg/m | 2.64 lb/ft |
| 2" NB | 60.33 mm (2.375") | 3.91 mm (0.154") | SCH 40S / STD | 5.52 kg/m | 3.66 lb/ft |
| 2" NB | 60.33 mm (2.375") | 5.54 mm (0.218") | SCH 80S / XS | 7.60 kg/m | 5.03 lb/ft |
| 2-1/2" NB | 73.03 mm (2.875") | 3.05 mm (0.120") | SCH 10S | 5.35 kg/m | 3.59 lb/ft |
| 2-1/2" NB | 73.03 mm (2.875") | 5.16 mm (0.203") | SCH 40S / STD | 8.77 kg/m | 5.89 lb/ft |
| 3" NB | 88.90 mm (3.500") | 3.05 mm (0.120") | SCH 10S | 6.56 kg/m | 4.34 lb/ft |
| 3" NB | 88.90 mm (3.500") | 5.49 mm (0.216") | SCH 40S / STD | 11.47 kg/m | 7.58 lb/ft |
| 3" NB | 88.90 mm (3.500") | 7.62 mm (0.300") | SCH 80S / XS | 15.51 kg/m | 10.26 lb/ft |
| 4" NB | 114.30 mm (4.500") | 3.05 mm (0.120") | SCH 10S | 8.50 kg/m | 5.62 lb/ft |
| 4" NB | 114.30 mm (4.500") | 6.02 mm (0.237") | SCH 40S / STD | 16.32 kg/m | 10.80 lb/ft |
| 4" NB | 114.30 mm (4.500") | 8.56 mm (0.337") | SCH 80S / XS | 22.67 kg/m | 15.00 lb/ft |
| 6" NB | 168.28 mm (6.625") | 3.40 mm (0.134") | SCH 10S | 14.04 kg/m | 9.30 lb/ft |
| 6" NB | 168.28 mm (6.625") | 7.11 mm (0.280") | SCH 40S / STD | 28.69 kg/m | 18.99 lb/ft |
| 6" NB | 168.28 mm (6.625") | 10.97 mm (0.432") | SCH 80S / XS | 43.21 kg/m | 28.60 lb/ft |
| 8" NB | 219.08 mm (8.625") | 3.76 mm (0.148") | SCH 10S | 20.27 kg/m | 13.62 lb/ft |
| 8" NB | 219.08 mm (8.625") | 8.18 mm (0.322") | SCH 40S / STD | 43.20 kg/m | 28.55 lb/ft |
| 8" NB | 219.08 mm (8.625") | 12.70 mm (0.500") | SCH 80S / XS | 65.63 kg/m | 43.39 lb/ft |
| Element | ASTM A312 TP310 (UNS S31000 / 1.4841) (%) | ASTM A312 TP310S (UNS S31008 / 1.4845) (%) |
|---|---|---|
| Carbon (C, Max) | 0.25 Max | 0.08 Max |
| Chromium (Cr) | 24.00 – 26.00 | 24.00 – 26.00 |
| Nickel (Ni) | 19.00 – 22.00 | 19.00 – 22.00 |
| Manganese (Mn, Max) | 2.00 | 2.00 |
| Silicon (Si, Max) | 1.50 | 1.50 (0.75 Max for some specs) |
| Phosphorus (P, Max) | 0.045 | 0.045 |
| Sulfur (S, Max) | 0.030 | 0.030 |
| Molybdenum (Mo, Max) | 0.75 Max | 0.75 Max |
| Iron (Fe) | Balance | Balance |
| Mechanical Property | ASTM A312 TP310 / TP310S Specified Limits | Typical Production Values |
|---|---|---|
| Tensile Strength, Ultimate (Min) | 515 MPa (75 ksi / 75,000 psi) | 550 – 650 MPa |
| Yield Strength (0.2% Proof, Min) | 205 – 215 MPa (30 ksi / 30,000 psi) | 240 – 310 MPa |
| Elongation in 2 in. / 50 mm (Min) | 35% – 40% Min | 45% – 55% |
| Hardness (Rockwell B / Brinell, Max) | 95 HRB Max / 217 HBW Max | 82 – 90 HRB (155 – 190 HBW) |
| Density & Melting Point | Density: 7.75 g/cm³ (7750 kg/m³) | Melting Range: 1400°C – 1450°C (2550°F – 2650°F) |
| Modulus of Elasticity | 200 GPa (29 x 10⁶ psi) | Electrical Resistivity: 720 nΩ·m |
| Thermal Expansion (0–100°C / 0–538°C) | 15.9 µm/m·°C (0–100°C) | 17.0 µm/m·°C (0–538°C) |
| Thermal Conductivity & Specific Heat | 14.2 W/m·K at 100°C | 18.7 W/m·K at 500°C | Specific Heat (0–100°C): 500 J/kg·K |
| Standard Designation | Governing Organization | Scope & Product Description |
|---|---|---|
| ASTM A312 / ASME SA312 | ASTM / ASME | Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes (TP310 / TP310S) |
| ASTM A213 / ASME SA213 | ASTM / ASME | Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes (TP310 / TP310S) |
| ASTM A358 / ASME SA358 | ASTM / ASME | Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature Service |
| ASTM A249 / ASME SA249 | ASTM / ASME | Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes |
| ASTM A376 / ASME SA376 | ASTM / ASME | Seamless Austenitic Steel Pipe for High-Temperature Central-Station Power Service |
| ASTM A409 / ASME SA409 | ASTM / ASME | Welded Large Diameter Austenitic Light-Wall Steel Pipe for Corrosive or High-Temperature Service |
| EN 10216-5 / DIN 17456 / 17458 | European / German Standards | Seamless Steel Tubes for Pressure Purposes (Grade 1.4841 / 1.4845 / X15CrNiSi25-21) |
| Indian Boiler Regulations (IBR) | Central Boilers Board | IBR Certified Steam and High-Pressure Stainless Steel Boiler Piping |
Stainless Steel 310 and 310S heat-resistant pipes and tubes are utilized across major thermal, furnace, and petrochemical applications:
Q1: What is the main metallurgical difference between SS 310 and SS 310S?
The difference is in the carbon concentration: SS 310 contains up to 0.25% Carbon for enhanced high-temperature creep strength, while SS 310S restricts Carbon to ≤0.08%. The lower carbon in 310S minimizes grain boundary carbide precipitation during welding and high-temperature service, reducing susceptibility to intergranular corrosion and embrittlement.
Q2: What is the maximum continuous working temperature for Stainless Steel 310 pipes?
Stainless Steel 310/310S pipes can operate continuously in air at temperatures up to 1100°C–1150°C (2012°F–2102°F) with minimal scaling. Under cyclic thermal conditions, the maximum recommended operating temperature is 1035°C (1895°F).
Q3: How does SS 310 perform in sulfur-bearing (sulfidation) environments?
Due to its high Chromium content (25%), SS 310 provides significantly better resistance to sulfurous oxidizing atmospheres than nickel-base alloys or standard 304/316 grades. However, in strongly reducing sulfurous gases (such as H2S), operating temperatures should be limited to prevent nickel-sulfide eutectic formation.
Q4: What certifications accompany Om Export India Pvt Ltd SS 310/310S pipes?
Every order is supplied with EN 10204 Type 3.1 / 3.2 Material Test Certificates, IBR Form III-A or Form III-D statutory documents, 100% Positive Material Identification (PMI) spectro analysis, 100% hydrostatic testing, and automated Eddy Current / Ultrasonic testing reports.
Contact OM Export India for pricing, technical support, stock availability and export enquiries.