24 July 2021 Inconel®
Inconel 686 Alloy Steel Bar
INCONEL® alloy 686 (UNS N06686/W.Nr. 2.4606) is a single-phase, austenitic Ni-Cr-Mo-W alloy offering outstanding corrosion-resistance in a range of severe environments. Its high nickel (Ni) and molybdenum (Mo) provide good resistance in reducing conditions, and high chromium (Cr) offers resistance to oxidizing media. Molybdenum (Mo) and tungsten (W) aid resistance to localized corrosion such as pitting. Iron (Fe) is closely controlled to enhance properties. Low carbon (C) helps minimize grain boundary precipitation to maintain corrosion-resistance in the heat-affected zones of welded joints. Resistance to general, pitting and crevice corrosion increases with the alloying (Cr+Mo+W) content, and INCONEL alloy 686 scores higher than competitive materials. INCONEL alloy 686 is protected by U.S. patent 5,019,184.
Its matched composition welding products, designated as INCO-WELD® filler metals and welding electrode 686 CPT® also offer exceptional as-welded resistance to sulfuric or hydrochloric acids, to mixtures of the two, and to crevice or pitting corrosion in hot concentrated acid chloride solutions. These welding products are also used for dissimilar and overmatched welding applications.
Inconel® 686 offers excellent resistance to general corrosion, stress-corrosion cracking and to pitting and crevice corrosion in a variety of aggressive media. It’s high nickel and molybdenum content provide good resistance in reducing conditions while the high chromium content offers resistance to oxidizing media. Localized corrosion resistance is further enhanced by the addition of tungsten. Carbon content is restricted to help minimize grain boundary precipitation to maintain the corrosion resistance in the heat-effected zone of welded areas.
Inconel® 686 also proves to be well suited in handling mixed acid solutions containing high concentrations of halides and has shown good resistance to mixed acid media with pH levels of 1 or less, and chloride levels of over 100,000 ppm.
INCONEL alloy 686 is used for resistance to aggressive media in chemical processing, pollution control, pulp and paper manufacture, and waste management applications.
Chemical Composition:
The following table shows the chemical composition of Inconel 686™.
| Element | Content (%) |
|---|---|
| Nickel, Ni | 59 |
| Chromium, Cr | 19-23 |
| Molybdenum, Mo | 15-17 |
| Iron, Fe | ≤ 5 |
| Tungsten, W | 3.0-4.40 |
| Manganese, Mn | ≤ 0.75 |
| Phosphorous, P | ≤ 0.040 |
| Sulfur, S | ≤ 0.020 |
| Titanium, Ti | 0.020-0.25 |
| Carbon, C | ≤ 0.010 |
Physical Properties:
The physical properties of Inconel 686™ are outlined in the following table.
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.72 g/cm³ | 0.315 lb/in³ |
| Melting point | 1338-1380 °C | 2440-2520 °F |
Mechanical Properties:
The mechanical properties of Inconel 686™ are provided below.
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 721.9 MPa | 104700 psi |
| Yield strength (@strain 0.200%) | 364 MPa | 52800 psi |
| Elastic modulus | 207 GPa | 30000 ksi |
| Shear modulus | 77 GPa | 11200 ksi |
| Poisson’s ratio | 0.34 | 0.34 |
| Elongation at break | 71% | 71% |
Thermal Properties:
The thermal properties of Inconel 686™ are given below.
| Properties | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@21-100°C/69.8-212°F) | 11.97 µm/m°C | 6.650 µin/in°F |