Nimonic 81 Plates | Fuel-Ash & Hot-Corrosion Shield for 800°C+ Service
Table of Contents:
When a coastal coal‑fired power station on India’s west coast lost three superheater banks in five years to fuel‑ash corrosion, every forced outage meant crores in lost generation, tube leaks, and emergency welds in SO₂‑laden flue gas. The turning point came when the boiler OEM switched tube shields and baffles from low‑alloy steels to Nimonic 81 Plates a 30% chromium nickel‑base alloy whose descaled weight loss in 75% Na₂SO₄ + 25% NaCl at 800°C is several times lower than Nimonic 80A, giving dramatically longer life in molten‑salt and vanadium pentoxide attack from high‑sulfur, high‑vanadium fuels.
Nimonic 81 (often listed as a precipitation‑hardenable nickel‑chromium alloy) was developed specifically for hot‑corrosion environments such as gas turbines, piston‑engine exhaust valves, and heat‑exchange plant contaminated by alkali metal sulfates and chlorides in flue gas. Compared with Nimonic 80A, it keeps similar elevated‑temperature strength but adds higher chromium (~30%) and optimized chemistry for much better resistance in SO₂, fuel ash, and salt‑shower tests at 800°C, where 80A shows several‑fold higher descaled weight loss.
Aurico Alloys LLP offers affordable, authentic Nimonic 81 Plates as a trusted supplier, manufacturer, and stockist for chemical, oil & gas, marine, pharma, and power generation industries, as well as hardware and industrial supply stores supplying solution‑treated material, ready for customer ageing, with EN 10204 3.1 MTC and full chemistry and mechanical reports. As a leading Nimonic 81 Plates supplier, stockist, exporter in India to abroad, the company supports Nimonic 81 plate suppliers in Mumbai for coal‑fired boiler tube shields and supports and gas‑turbine hot‑section fabricators who need reliable protection in 800°C+ salt and ash attack.
High-quality Nimonic 81 Plates ready for industrial use.
Specification Overview
| Supplier & Manufacturer | Aurico Alloys LLP |
|---|---|
| Grade | Nimonic 81 (often designated Alloy 81) |
| UNS | — |
| Standards | Supplied to Special Metals proprietary specification for hot-rolled plate and sheet; no ASTM or AMS specification is published for this grade |
| Typical Thickness Range | 4.75 mm – 150 mm |
| Heat Treatment | Usually supplied solution‑treated at ~1098°C for ~8 h, air cooled; ageing done by fabricator for final properties. |
| Finish | Mill finish, pickled, bright annealed, or ground; cut‑to‑size tube shields and baffles available |
| Documentation | EN 10204 3.1 MTC, PMI, corrosion / hardness test reports as ordered |
| Price | INR 1,200 – 1,600 per kg. Indicative USD 14 – 19 per kg; quoted against grade, form, size and quantity. |
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | — |
| Density | 8.06 g/cm3 |
| Melting range | 1305-1375 °C |
| Specific heat (20 °C) | 461 J/kg·°C |
| Thermal conductivity (20 °C) | 10.9 W/m·°C |
| Electrical resistivity (20 °C) | 1.27 µΩ·m |
| Coefficient of expansion (20-100 °C - extruded and stretched bar) | 11.1 µm/m·°C |
| Coefficient of expansion (20-100 °C - cold rolled sheet) | 11.7 µm/m·°C |
| Dynamic modulus of elasticity (20 °C - extruded bar) | 196 GPa |
| Dynamic modulus of elasticity (20 °C - sheet) | 212 GPa |
| Modulus of rigidity (20 °C - dynamic torsional) | 80 GPa |
| Plate, sheet and strip specification | Mill specification |
Identifiers and physical constants for Nimonic 81. A dash means no such designation is published for this grade.
Stock & Product Availability
Power OEMs and EPCs source fuel ash corrosion resistant Nimonic 81 plates for thermal power plant components such as tube shields, spacer bars, and baffles in superheater and reheater zones where molten sulfates and chlorides condense. Fabricators also specify high chromium Alloy 81 plates for industrial furnace baffles and structural parts that see 750–850°C with salt deposits.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Carbon (C) | 0.05 nominal | |
| Silicon (Si) | 0.50 nominal | |
| Copper (Cu) | 0.20 nominal | |
| Iron (Fe) | 1.0 nominal | |
| Manganese (Mn) | 0.50 nominal | |
| Chromium (Cr) | 30.0 nominal | |
| Titanium (Ti) | 1.8 nominal | |
| Aluminium (Al) | 0.9 nominal | |
| Cobalt (Co) | 2.0 nominal | |
| Molybdenum (Mo) | 0.30 nominal | |
| Boron (B) | 0.003 nominal | |
| Zirconium (Zr) | 0.06 nominal | |
| Sulfur (S) | 0.015 nominal | |
| Nickel (Ni) | — | Balance |
Nominal composition for Nimonic 81. These are nominal figures rather than acceptance limits, and they are not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property | Typical Value (Solution + Aged) |
|---|---|
| Ultimate Tensile Strength | ≈874 MPa |
| 0.2% Yield Strength | ≈565 MPa |
| Elongation | ≈14 % |
| Recommended high‑temperature use | Up to ≈800°C in load‑bearing, higher for short‑term exposure |
Applications & Benefits
- Power & Boilers: Nimonic 81 plate suppliers in Mumbai for coal‑fired boiler tube shields and supports; fuel ash corrosion resistant Nimonic 81 plates for thermal power plant components exposed to molten Na₂SO₄/NaCl and vanadium‑bearing deposits from heavy oils.
- Oil, Gas & Marine: Nimonic 81 plate stockist in Mumbai for marine diesel engine exhaust valves and heads, vanadium pentoxide resistant Alloy 81 plates for oil refinery crude heaters, and Nimonic 81 nickel alloy plates for offshore platform flare tips and burner nozzles.
- Chemical & Pharma: Nimonic 81 plates for chemical waste incinerators and hazardous material processing, hot corrosion resistant Nimonic 81 plates for pharmaceutical waste treatment systems, and durable Alloy 81 plates for chemical reactors operating in high‑sulfur atmospheres.
- Heat‑exchange & Seals: Custom cut Nimonic 81 plate sizes for specialty chemical plant heat exchangers and Nimonic 81 cold rolled (CR) plates in Mumbai for precision high‑temperature seals where dimensional stability and hot‑corrosion resistance are both critical.
- Sourcing & Compliance: Verified Nimonic 81 plate stockholders in India with MTC EN 10204 3.1 certification, serving as Nimonic 81 plate exporters in Mumbai for global heavy‑oil processing and waste‑to‑energy plants demanding traceability and reproducible fuel‑ash performance.
FAQ & Search Trends
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Nimonic 81 Plates from Aurico Alloys LLP combine high‑chromium UNS‑type 06081 chemistry with proven hot‑corrosion and fuel‑ash resistance at ~800°C, giving coal‑fired boilers, gas turbines, marine exhausts, and chemical incinerators a long‑life shield where stainless steels, low‑alloy steels, and even conventional superalloys rapidly waste away in molten salt and vanadium attack so are your most critical high‑temperature, high‑sulfur assets yet protected by Nimonic 81’s fuel‑ash‑resistant plate technology?