A solution-annealed nickel-molybdenum-chromium alloy with the addition of tungsten, C276 exhibits excellent corrosion resistance in a wide range of severe environments.
| % | Ni | Cr | Mo | W | Co | C | Mn | Si | P | S | Fe | V |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | Balance | 14.5 | 15 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 0 |
| Max | Balance | 16.5 | 17 | 4.5 | 2.5 | 0.01 | 1 | 0.08 | 0.04 | 0.03 | 7 | 0.35 |
Alloy C276, with a high nickel contents, is immune to chloride-induced stress corrosion cracking. The high molybdenum and chromium contents allow the alloy to perform in oxidising, non-oxidising and mixed acids media, whilst exhibiting outstanding resistance to pitting and crevice corrosion attack. The addition of tungsten inhibits the development of pits. Finally, C276 is suitable for off-shore applications where hydrogen-sulphide(H2S) stress corrosion cracking resistance is essential.
In aggressive or corrosive environments when other alloys have failed, many companies have then turned to C276 alloy – one of the most corrosion resistant alloys on the market.
Industries where C276 is utilised are petrochemical and chemical processing, power generation, pharmaceutical, pulp and paper production and waste treatment to name a few.
| Mechanical & Physical Properties | 21⁰C | 100⁰C | 200⁰C | 300⁰C | 400⁰C |
|---|---|---|---|---|---|
| Ultimate Tensile Strength for sheet ≤ 5 mm thick | 750-1000 | ||||
| Ultimate Tensile Strength for sheet 5 to ≤ 20 mm thick | 700-950 | ||||
| Ultimate Tensile Strength for bar ≤ 90 mm thick | 700-950 | ||||
| 0.2% Yield Strength for sheet ≤ 50 mm thick | 280 | 240 | 220 | 195 | |
| 0.2% Yield Strength for sheet 5 to ≤ 20 mm thick | 255 | 255 | 200 | 170 | |
| 0.2% Yield Strength for bar ≤ 90 mm thick | 255 | 225 | 200 | 170 | |
| Elongation, % for sheet ≤ 5 mm thick | 30 | ||||
| Elongation, % for sheet 5 to ≤ 20 mm thick | 25 | ||||
| Elongation, % for bar ≤ 90 mm thick | 35 | ||||
| Charpy Impact V-notch mean value / J | 96 (56 when welded) | ||||
| Charpy Impact V-notch indicidual value / J | 67 (39 when welded) |
| Media | Common Name | Temp °F (°C) | Corrosion Rate (mpy) |
|---|---|---|---|
| 80% C2H4O2 | Acetic Acid | Boiling | 0.15 |
| 10% NH3Br | Ammonium Bromide | 176 (80) | Nil |
| 10% NH3Br | Ammonium Bromide | Boiling | Nil |
| 10% FeCl3 | Ferric Chloride | Boiling | 2 |
| 88% CH2O2 | Formic Acid | Boiling | 1 |
| 0.2% HCl | Hydrochloric Acid | Boiling | 0.60 |
| 1% HCl | Hydrochloric Acid | Boiling | 13.3 |
| 2% HCl | Hydrochloric Acid | Boiling | 43 |
| 5% HCl | Hydrochloric Acid | 140 (60) | 10 |
| 20% HCl | Hydrochloric Acid | 212 (100) | 154 |
| 3% HF | Hydrofluoric Acid | 176 (80) | 53 |
| 10% HF | Hydrofluoric Acid | 75 (24) | 2 |
| 10% HF | Hydrofluoric Acid | 176 (80) | 28 |
| Concentrated HF | Hydrogen fluoride | 75 (24) | 24 |
| Concentrated HF | Hydrogen fluoride | 176 (80) | 80 |
| 10% HBr | Hydrogen Bromide | 176 (80) | <1 |
| 10% HBr | Hydrogen Bromide | Boiling | <1 |
| 10% HNO3 | Nitric Acid | Boiling | 15 |
| 65% HNO3 | Nitric Acid | Boiling | 888 |
| 20% H3PO4 | Phosphoric Acid | Boiling | <1 |
| 60% H3PO4 | Phosphoric Acid | Boiling | 1 |
| 85% H3PO4 | Phosphoric Acid | 212 (100) | 5 |
| 85% H3PO4 | Phosphoric Acid | Boiling | 121 |
| 50% NaOH | Sodium Hydroxide | Boiling | 1 |
| 10% H2SO4 | Sulphuric Acid | Boiling | 20 |
| 20% H2SO4 | Sulphuric Acid | 176 (80) | 3 |
| 40% H2SO4 | Sulphuric Acid | 176 (80) | 5 |
| 80% H2SO4 | Sulfphuric Acid | 176 (80) | 4 |
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