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Inox Steel India supplies a comprehensive range of Alloy Steel Seamless Tubes commonly used in high-temperature and high-pressure applications where conventional carbon steel or stainless steel tubes cannot perform reliably. Manufactured strictly as per ASTM A213 Grades T11, T22 and T91, these tubes are engineered to deliver exceptional creep resistance, oxidation stability and long-term metallurgical reliability under extreme service conditions.
Alloy steel tubes are the backbone of modern thermal power plants, petrochemical heaters, refinery boilers, HRSG units, and supercritical steam systems. Their superior Cr-Mo and Cr-Mo-V-Nb chemistries enhance strength, corrosion resistance at elevated temperatures and long-term creep performance.
✔ Key Grades Supplied by Inox Steel India
Each grade is manufactured using hot finished, cold drawn, normalized, tempered or quenched & tempered processes, depending on the required service environment. T91, in particular, undergoes stringent heat treatment cycles to achieve its superior creep rupture strength.
These tubes are widely used in:
Inox Steel India is recognized globally for delivering alloy steel tubes that maintain tight tolerances, excellent wall thickness uniformity, consistent microstructure, and high mechanical stability throughout their service life. We supply to EPC contractors, boiler manufacturers, refineries, chemical plants and power utilities across India, Middle East, Africa and Europe.
| Parameter | Alloy Steel Seamless Tubes |
|---|---|
| Applicable Standards | ASTM A213 / ASME SA213 • EN 10216-2 • ASTM A335 (equivalent for pipes) |
| Grades Available | T11 (1.25Cr–0.5Mo) • T22 (2.25Cr–1Mo) • T91 (9Cr–1Mo–V–Nb) |
| Material Class | Chromium-Molybdenum Alloy Steel (High-Temperature Service) |
| Manufacturing Process | Hot Finished Seamless (HFS) • Cold Drawn Seamless (CDS) • Normalized • Tempered • Quenched & Tempered (T91) |
| Size Range (OD) | 10 mm to 273 mm OD |
| Thickness Range | 1.5 mm to 30 mm |
| Length Options | 6m • 12m • Cut Length • U-Bent Tubes for Boilers/Superheaters |
| Mechanical Properties (Typical) | Tensile Strength: 415–620 MPa • Yield Strength: 205–440 MPa • Elongation: 20–30% |
| Temperature Capability | T11: Up to ~550°C • T22: Up to ~600°C • T91: Up to ~650–700°C (creep-resistant) |
| Heat Treatment | T11/T22: Normalized & Tempered • T91: Quenched & Tempered (mandatory) |
| Surface Finish Options | Black • Varnished • Phosphated • Shot-blasted • Oiled |
| Dimensional Tolerances | Tight OD/WT tolerances as per ASTM A213 for high-pressure & high-temp applications |
| End Finish | Plain End • Bevel End (37.5°) • Deburred Ends |
| Mandatory Testing | Hydrostatic Test • Eddy Current • Hardness • Tensile Test • Flattening/Flaring |
| Special/Optional Tests | IGC • Impact Test (Charpy V-Notch for T91) • Stress Rupture • UT (Ultrasonic) • Microstructure Review |
| NDT Compliance | EC / Hydro / UT as per application & customer requirement |
| Documentation Provided | MTC EN 10204 3.1 • Normalizing/Tempering Charts • NDT Reports • Chemical/Mechanical Test Reports |
| Corrosion Resistance | Suitable for high-temperature oxidation & steam corrosion (not ideal for acidic fluids unless clad) |
| Key Grade Benefits | T11: Economical high-temp steel • T22: Improved creep resistance • T91: Superior creep rupture strength for supercritical boilers |
| Typical Applications | Superheaters • Reheaters • Boilers • Heat Exchangers • Power Plants • Petrochemical Heaters • Refineries • Furnace Tubes • HRSG Units |
Alloy steel seamless tubes are specifically designed for elevated temperature, high pressure and long-term creep resistance. Their Cr–Mo and Cr–Mo–V–Nb chemistry makes them indispensable in thermal power, petrochemical, and superheater/reheater systems.
🔹 1. Superheaters & Reheaters
High creep strength and oxidation resistance make these grades ideal for continuous high-temperature steam exposure.
Applications:
Best Grade: T91 (9Cr–1Mo–V–Nb)
🔹 2. High-Pressure Boilers
Alloy tubes withstand pressure surges, thermal cycling and steam corrosion better than carbon steel tubes.
Used In:
Preferred Grades: T11, T22
🔹 3. Petrochemical & Refinery Heaters
These tubes maintain structural integrity under carburizing, oxidation and high radiant heat environments.
Applications:
Recommended Grades: T22 / T91 depending on severity
🔹 4. Heat Recovery Steam Generators (HRSG)
Used in combined-cycle power plants where precise thermal stability is critical.
Applications:
Preferred Grades: T22 / T91
🔹 5. Power Generation & Turbine Systems
Stable performance under temperature fluctuations & extended operation periods.
Applications:
Recommended: T11 / T22 / T91
| Application | Recommended Grade | Why |
|---|---|---|
| Standard boilers | T11 | Economical high-temperature steel |
| Medium to high-temperature service | T22 | Better creep & oxidation resistance |
| Ultra-high temperature & pressure | T91 | Excellent creep rupture strength |
| Petrochemical heaters | T22 | 2.25Cr–1Mo chemistry for oxidation resistance |
| Supercritical & ultra-supercritical boilers | T91 | Required by most thermal power OEMs |
| Tube Type | OD Range | WT Range | Typical Use |
|---|---|---|---|
| T11 Boiler Tubes | 19.05–76.2 mm | 2–12 mm | Boilers & heaters |
| T22 Heat Exchanger/Boiler Tubes | 19–89 mm | 2.5–14 mm | HRSG, refinery heaters |
| T91 Superheater/Reheater Tubes | 25–127 mm | 3–20 mm | Supercritical systems |
(Custom OD/WT available upon request.)
| Grade | Price Range (₹/kg) | Notes |
|---|---|---|
| T11 | ₹180 – ₹260 | Standard boiler tubes |
| T22 | ₹240 – ₹350 | Higher creep resistance |
| T91 | ₹380 – ₹600 | Premium superheater grade, Q&T |
Prices depend on OD, WT, heat treatment, code compliance & project volume.
Each tube undergoes multiple stringent tests to ensure high-temperature reliability.
Mandatory Tests
Special Tests for High-Temperature Grades
Documentation
Inox Steel India is a reliable supplier of high-temperature Alloy Steel Seamless Tubes used in power plants, petrochemical heaters, boilers and refinery process systems. Our tubes comply with ASTM A213 T11, T22 and T91, ensuring superior creep resistance, high-temperature strength and long-term metallurgical stability.
✔ What Sets Our Alloy Steel Tubes Apart
Our tubes are trusted by EPC contractors, boiler OEMs, energy utilities and petrochemical manufacturers worldwide.
| Industry | Applications |
|---|---|
| Thermal Power Plants | Superheaters, reheaters, boiler tubes |
| Petrochemical Plants | Fired heaters, reformer coils |
| Oil Refineries | Furnace tubes, radiant coils |
| HRSG & Combined Cycle Plants | Superheater modules, evaporator coils |
| Process Heaters | Heat transfer tubes in high-temp furnaces |
| Chemical Plants | High-pressure steam lines |
| Industrial Boilers | Pressure tubing & boiler coils |
Our alloy steel tubes are used in subcritical, supercritical and ultra-supercritical boiler systems.
We export alloy steel seamless tubes to 40+ countries, ensuring safe delivery and international standards compliance.
Export Packaging Includes:
Major Export Markets:
UAE • Saudi Arabia • Qatar • Kuwait • Oman
Europe • Turkey • South Africa • Nigeria
Bangladesh • Vietnam • Indonesia
All shipments include heat treatment charts and full TPI documentation when required.
We help with:
✔ Grade selection (T11 vs T22 vs T91)
✔ HRSG & boiler tube recommendations
✔ Thermal & creep performance guidance
✔ TPI coordination (Lloyds / BV / SGS / TÜV)
✔ Project-based pricing & delivery schedules
Request size charts, heat treatment charts, and MTC samples.
52-A, Mulji Thackersi Bldg, Islampura Street, Shop No. 10, Near Alankar Cinema, Mumbai – 400 004
alloy@inoxsteelindia.in
+91 9930796690
T91’s creep rupture properties depend on a controlled martensitic microstructure formed through Q+T.
Alloy steel tubes are designed for high temperature, not corrosive liquids. For liquid corrosion, stainless or clad solutions are recommended.
Yes — we maintain ready stock of common OD/WT sizes for immediate dispatch.
Yes, both grades are widely used in superheaters, reheaters, and steam piping in supercritical & ultra-supercritical units.
Inox Steel India supplies alloy steel seamless tubes in grades ASTM A213 T11, T22 & T91 for boilers, superheaters, reheaters, HRSG units and petrochemical heaters. High-temperature, high-pressure tubing with N+T / Q+T heat treatment and full MTC 3.1.