INCOLOY is an alloy composed of nickel-iron-chromium, with additions of molybdenum and copper. These alloys are categorized as super alloys and exhibit excellent corrosion resistance and high strength. Some of the INCOLOY alloys are specifically made to resist selected reagents. These alloys are capable of functioning even at high temperatures.
INCOLOY alloy 020 exhibits excellent corrosion resistance in chemical environments that contain sulphuric acid, chlorides, phosphoric acid and nitric acid. It is easy to fabricate this alloy to form mixing tanks, heat exchangers, pickling equipment etc. The standard forms in which this alloy is available are round, flats, pipe, tube, strip and wire.
| Zeon Grade | Alloy Name | UNS | EN / DIN / W Nr. | Trademarks |
|---|---|---|---|---|
| Zeon20 | Alloy 20 | UNS N08020 | 2.4660 | Incoloy 020 |
| Element | Content (%) |
|---|---|
| Nickel, Ni | 32-38 |
| Iron, Fe | 35 |
| Chromium, Cr | 19-21 |
| Copper, Cu | 3-4 |
| Molybdenum, Mo | 2-3 |
| Manganese, Mn | ≤2 |
| Niobium, Nb | ≤1 |
| Silicon, Si | ≤1 |
| Others | Remainder |
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.05 gm/cm3 | 0.291 lb/in3 |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength(annealed) | 620 MPa | 89.9 ksi |
| Yield strength(annealed) | 300 MPa | 43.5 ksi |
| Elongation at Break | 41% | 41% |
| Corrosion Resistance Properties of Alloy 20 |
|---|
| Alloy 20 has excellent corrosion resistance to sulphuric, phosphoric and organic acids and to aqueous solutions of their salts. Resistance to nitric acid is also good. Due to the controlled chemical composition, the alloy also has excellent resistance to such forms of corrosion as intergranular corrosion and stress corrosion. The molybdenum content ensures good resistance to pitting and crevice corrosion. Optimum corrosion resistance can only be obtained if the material is in the correct metallurgical condition and clean. |
| Welding: | UNS N08020 can be welded by shielded metal arc welding, gas tungsten arc welding and gas metal arc welding. The filler metal is usually an INCONEL alloy. |
|---|---|
| Hot Working | UNS N08020 may be hot-worked in the range 1150 to 900 °C (2100 to 1650 °F). The final hot-working temperature must not exceed 950 °C (1740 °F). Cooling should be by water quenching or as fast as possible. |
| Cold Working | Cold working should be carried out on annealed material. UNS N08020 has a work-hardening rate similar to that of austenitic stainless steel and the forming equipment must be adapted accordingly. When cold working is performed, interstage annealing may become necessary. After cold reductions of more than 15 %, a final stabilizing anneal is required before use. |
| Heat Treatment | Soft or stabilizing annealing should be carried out in the temperature range 920 to 960 °C (1690 to 1760 °F), preferably at about 950 °C (1740 °F). Water quenching or rapid air cooling is recommended for thicknesses above about 3 mm (1/8 in.) and is essential for maximum corrosion resistance. |
| Machining | UNS N08020 should be machined in annealed condition. The alloy’s high work-hardening rate should be considered, i.e. only low surface cutting speeds are possible compared with low-alloy standard austenitic stainless steel. Tools should be engaged at all times. Heavy feeds are important in getting below the work-hardened ‘skin’. |
| Applications | Applications of Alloy 20 include chemical processing, pollution control, oil and gas recovery, acid production, pickling operations, nuclear fuel reprocessing, and handling of radioactive wastes. |