Nickel and nickel alloys · Alloy 686 / Inconel 686 / UNS N06686 / 2.4606
Inconel 686 Alloy (UNS N06686): Engineering Characteristics and Application
Engineering Analysis and Operational Properties of Inconel 686 (Alloy 686)
Inconel 686 (Alloy 686 / UNS N06686) is an austenitic nickel-chromium-molybdenum material, strengthened by tungsten addition. Its composition is designed to provide maximum corrosion resistance in the most aggressive industrial environments. The unique combination of alloying elements (Cr, Mo, W) ensures excellent resistance to localized corrosion, including pitting and crevice corrosion, as well as complete immunity to chloride stress corrosion cracking (SCC).
EV Group China technologists confirm the effectiveness of using Alloy 686 in critical components of chemical and oil and gas equipment. The alloy is indispensable in flue gas desulfurization (FGD) systems, in the production of equipment for industrial waste processing and wastewater treatment. Its thermal stability and inertness to high-temperature acidic environments and seawater make it a preferred material for offshore platforms, subsea pipelines, and heat exchangers operating under extreme conditions.
| Product Type | International Marking | Key Specifications | European Analogues | European Analogues | ||
|---|---|---|---|---|---|---|
| Pipe, strip, sheet steel (plates), forgings, wire, hexagonal bar | Alloy 686, Inconel 686, UNS N06686 | ASTM | ASME | W.Nr. | DIN | ISO |
| Pipe, strip, sheet steel (plates), forgings, wire, hexagonal bar | Alloy 686, Inconel 686, UNS N06686 | B366, B462, B472, B564, B575, B619, B622, B626 | SB366, SB462, SB472, SB564, SB575, SB619, SB622, SB626 | 2.4606 | NiCr21Mo16W - 17744, 17750, 17752 | NiCr21Mo16W4 - 18274 |
Matrix Chemical Composition of Inconel 686, %
| Cr | 19.0-23.0 |
|---|---|
| C | <0.01 |
| S | <0.02 |
| Ti | 0.02-0.25 |
| P | <0.04 |
| Si | <0.08 |
| Mn | <0.75 |
| Fe | <1.0 |
| W | 3.0-4.4 |
| Mo | 15.0-17.0 |
| Ni | Balance |
Mechanical Characteristics of Alloy 686
| Material Condition | Annealed | Spring temper |
|---|---|---|
| Operating temperature (static load), ksi | <145 | 174-232 |
| Tensile strength (typical), N/mm² | <1000 | 1200-1600 |
Engineering and Technological Comment from EV Group China:
The given mechanical strength values are typical for the material in the annealed and strengthened conditions. For designing components operating at cryogenic or high temperatures, as well as under cyclic loads, calculations must be performed considering the appropriate fatigue and creep curves. EV Group China provides complete state diagrams and test reports upon request for specific material batches.
Key Physical Constants of Alloy N06686
| Alloy Density | Melting Range | Average Coefficient of Thermal Expansion | Modulus of Elasticity (Young's) |
|---|---|---|---|
| 8.73 g/cm³ | 1338 - 1380 °C | 11.97 µm/m°C (in the range 20 – 100 °C) | 207.0 kN/mm² |