Inconel 690 Plates | UNS N06690 High-Chromium Plates for Nuclear, Thermal Power & Harsh Oxidizing Service
Table of Contents:
When a nuclear and thermal power operator reviewed its fleet, the most worrisome findings were not in the turbines but inside aging steam generator tubing and high-temperature heater shells, where legacy alloys had started showing stress corrosion cracking and oxide spallation after decades in high‑temperature, high‑pressure, mildly alkaline water containing chlorides and oxygen. A shift to Inconel 690 Plates (UNS N06690, W.Nr. 2.4642) – a high‑chromium nickel alloy originally developed to overcome Alloy 600 SCC issues – brought a chemistry with roughly 58–63% nickel and about 27–31% chromium that achieves excellent resistance to oxidizing aqueous environments, low corrosion rates in many acids (for example, around 0.8 mm/year in 20% phosphoric acid at 60°C and below 0.8 mm/year to 85% acid at 80°C) and markedly better steam‑generator stress corrosion cracking performance than Alloy 600, allowing later generations of nuclear steam generators and power‑plant components to meet more demanding design lives.
INCONEL alloy 690 (UNS N06690 / W.Nr. 2.4642) is described as a high‑chromium nickel alloy with excellent resistance to many corrosive aqueous media and high‑temperature atmospheres, particularly oxidizing conditions. The substantial chromium content (about 30%) gives it outstanding resistance to oxidizing chemicals and high‑temperature oxidizing gases, while the high nickel content imparts resistance to stress‑corrosion cracking in chloride‑containing environments and sodium hydroxide solutions, making it attractive for nuclear steam generator tubing, pickling systems and nitric or nitric/hydrofluoric acid services.
For procurement heads, design engineers, fabricators, OEMs and hardware or industrial supply stores serving chemical, oil & gas, marine, pharma and power‑generation industries, Inconel 690 plates address a recurring question: which alloy offers better stress‑corrosion cracking resistance and oxidizing acid performance than standard stainless steels, Alloy 600 or some lower‑chromium nickel alloys, without sacrificing weldability and mechanical margin. Plate property tables from suppliers list typical tensile strengths around 590–760 MPa, 0.2% yield strengths around 240–345 MPa, elongation around 30%, with tests showing low corrosion rates in phosphoric acid through 85% at 80°C (about 0.03 mm/year at some concentrations) and good resistance in nitric and nitric/hydrofluoric mixtures used for nuclear fuel reprocessing and stainless pickling, reinforcing the case for Alloy 690 as a premium upgrade where oxidizing corrosion and SCC control life.
Aurico Alloys LLP can support these needs as an affordable, authentic Inconel 690 Plates supplier, stockist and exporter in India to abroad, supplying UNS N06690 / 2.4642 plates per ASTM B168 / ASME SB168 and associated EN/DIN plate standards with NABL‑supported Mill Test Certificates for nuclear steam‑generator components, thermal power plant applications, oxidizing‑acid chemical equipment, offshore flare hardware and high‑temperature pharma and aerospace systems. This aligns closely with search intent such as “Inconel 690 plate suppliers in Mumbai for nuclear steam generator tubes and components”, “ASTM B168 Inconel 690 plates for high-temperature thermal power plant applications”, “Stress corrosion cracking resistant Alloy 690 plates for nuclear waste vitrification”, “Inconel 690 plate price per kg in Mumbai for coal-gasification units and heaters”, “Inconel 690 plate stockist in Mumbai for chemical process equipment handling oxidizing acids”, “Inconel 690 plate stockholders in Maharashtra for offshore oil and gas flare tips” and “Verified Inconel 690 plate exporters in India with Mill Test Certificates (MTC) and NABL reports”.
High-quality Inconel 690 Plates ready for industrial use.
Specification Overview
| Supplier & Role | Aurico Alloys LLP – Inconel 690 plate suppliers in Mumbai for nuclear steam generator tubes and components, thermal power plant heaters, coal‑gasification units, oxidizing‑acid chemical equipment, offshore flare tips and high‑temperature pharma and aerospace fabrications, with NABL‑backed EN 10204 3.1 MTCs for India and export projects. |
|---|---|
| Alloy Description | High‑chromium nickel alloy (about 30% Cr, balance Ni with minor Fe) designed for excellent corrosion resistance in oxidizing aqueous media and high‑temperature oxidizing and sulfur‑containing atmospheres, with strengthened resistance to stress‑corrosion cracking compared with Alloy 600. |
| UNS / Werkstoff / EN | UNS N06690; W.Nr. 2.4642; commonly referenced as Inconel 690 or Alloy 690 in EN 10302 and related product standards. |
| Main Plate Standards | ASTM B168 / ASME SB168 for plate, sheet and strip of Ni‑Cr‑Fe alloys including UNS N06690; EN 10302 for heat‑resistant plates; used within ASME nuclear and fossil plant design documents in conjunction with nuclear‑specific specifications for steam generator tubing. |
| Thickness Range | 4.75 mm – 150 mm |
| Corrosion Focus | Resistance to high‑temperature water stress‑corrosion cracking in nuclear steam generators, nitric and nitric/hydrofluoric acids, phosphoric acid up to 85% at 80°C, oxidizing acids and sulfur‑containing high‑temperature atmospheres. |
| Target Users | Nuclear and thermal power plants, petrochemical and hazardous‑waste incineration units, nitric and phosphoric acid producers, offshore oil and gas operators, marine fabricators, pharma and aerospace OEMs and industrial supply stores focused on high‑integrity projects. |
UNS & Equivalent Grades
| Property | Value |
|---|---|
| UNS number | N06690 |
| Werkstoff / EN number | 2.4642 |
| Density | 8.19 g/cm3 |
| Melting range | 1343-1377 °C |
| Specific heat | 450 J/kg·°C |
| Electrical resistivity | 1.148 µΩ·m |
| Magnetic permeability (at 200 oersted / 15.9 kA/m) | 1.001 |
| Young's modulus | 211 GPa |
| Poisson's ratio | 0.289 |
| Plate, sheet and strip specification | ASTM B168 / B906 |
Identifiers and physical constants for Inconel 690. A dash means no such designation is published for this grade.
Stock & Product Availability
As an ASTM B168 Inconel 690 plate stockist in Mumbai, Aurico Alloys LLP can supply annealed plates for nuclear and thermal power plant components, high‑temperature heaters, coal‑gasification vessels, nitric and phosphoric acid equipment and oxidizing gas ducting, with typical thickness ranges suited to tube‑sheet cladding, channel covers, baffles, support plates and overhead condenser shells. Supplier data list mechanical properties for B168 plate with tensile strengths around 590 MPa, yield strengths around 240 MPa and elongation around 30% in annealed condition, while technical bulletins show higher strengths (tensile ~760 MPa, yield ~345 MPa, elongation ≥30%) for certain product forms, giving engineers flexibility to match strength with process conditions.
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Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Nickel (Ni) | 58.0 | — |
| Chromium (Cr) | 27.0 | 31.0 |
| Iron (Fe) | 7.0 | 11.0 |
| Carbon (C) | — | 0.05 |
| Silicon (Si) | — | 0.50 |
| Manganese (Mn) | — | 0.50 |
| Sulfur (S) | — | 0.015 |
| Copper (Cu) | — | 0.50 |
Composition limits for Inconel 690. These are specification limits for the grade, not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property (Annealed Plate / Sheet) | Typical Value – Inconel 690 / UNS N06690 |
|---|---|
| Ultimate Tensile Strength (room temp.) | ≈590 MPa minimum for B168 plate; up to ≈760 MPa reported for some product forms. |
| 0.2% Yield Strength (room temp.) | ≈240 MPa minimum for plate; around 345 MPa cited as a generic minimum in some mechanical datasheets. |
| Elongation | ≥30% in 50 mm gauge length for plate; some supplier data list ~30% as typical. |
| Hardness | Commonly reported around 200–250 HB in typical product conditions. |
| Service Temperature Range | Good mechanical strength and oxidation resistance up to ~1000°C, with excellent performance in high‑temperature water and oxidizing atmospheres used in nuclear and thermal power applications. |
| Corrosion Behaviour | Low corrosion rates in phosphoric acid up to 85% at 80°C (~0.03 mm/year in some compositions) and robust resistance in nitric and nitric/hydrofluoric acid systems; excellent SCC resistance in high‑temperature water compared with Alloy 600. |
Applications & Benefits
- Power Generation & Nuclear: Inconel 690 plates are used for nuclear steam generator tubes and support structures, high‑temperature thermal power plant heaters, coal‑gasification units and nuclear waste vitrification hardware due to high chromium content, excellent SCC resistance in high‑temperature water and strong oxidation resistance.
- Chemical & Petrochemical: High‑chromium Alloy 690 plates support nitric acid production tail‑gas reheaters, chemical process equipment handling oxidizing acids, UNS N06690 plates for sulfuric acid processing in refineries and hazardous‑waste incineration plant components where oxidizing gases and acids combine.
- Marine, Oil & Gas: Marine‑grade Inconel 690 plates are applied in salt‑water and sulfur‑gas environments, offshore oil and gas flare tips, subsea thermal equipment and heat‑exchanger plates where durability in oxidizing, sulfur‑bearing and chloride‑containing atmospheres is crucial.
- Pharma, Aerospace & Sourcing: High‑purity plates support pharmaceutical high‑temperature sterilization units, while aerospace engine and ducting parts benefit from the alloy’s oxidation resistance and strength; verified plate exporters in India offer NABL‑supported MTCs and custom‑cut sizes for overhead condensers, ducting and instrument panels.
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
Inconel 690 Plates from Aurico Alloys LLP, supplied as UNS N06690 / W.Nr. 2.4642 plate to ASTM B168 / ASME SB168 and relevant EN/DIN standards with NABL‑supported Mill Test Certificates, provide chemical, oil & gas, marine, pharma and power‑generation users with a high‑chromium nickel alloy that pairs strong mechanical performance with excellent stress‑corrosion cracking and oxidizing‑acid resistance for nuclear steam generators, thermal power heaters, nitric and phosphoric acid plants, offshore flare systems and high‑temperature process and aerospace equipment are your most oxidation‑ and SCC‑critical assets still dependent on borderline stainless or legacy nickel alloys instead of fully optimised Inconel 690 plates?