Hastelloy C-276 Nickel Based Superalloy
Hastelloy C-276 is a nickel-chromium-molybdenum alloy containing tungsten. It has a very low silicon-carbon content and is considered a universal anti-corrosion alloy. Hastelloy C-276 has excellent corrosion resistance to most corrosive media in both oxidation and reduction atmospheres, and has excellent resistance to pitting, crevice corrosion and stress corrosion. The higher content of molybdenum and chromium makes the alloy resistant to chloride ion corrosion, and the tungsten element further improves the corrosion resistance.
At the same time, Hastelloy C-276 alloy is one of the only materials that are resistant to corrosion by humid chlorine, hypochlorite and chlorine dioxide solutions, and has significant effects on high-concentration chloride solutions such as ferric chloride and copper chloride corrosion resistance. It is suitable for sulfuric acid solutions of various concentrations and is one of the few materials that can be applied to hot concentrated sulfuric acid solutions.
Hastelloy C276 alloy has been widely used in the chemical and petrochemical fields, such as in components and catalytic systems that contact chloride-containing organics. This material is especially suitable for use in high temperature, mixed with impurities of inorganic and organic acids (such as formic acid and acetic acid), and seawater corrosive environments.
Chemical Composition:
Mo | Cr | Fe | W | Co | Mn | C | V | P | S | Si |
---|---|---|---|---|---|---|---|---|---|---|
15.0-17.0 | 14.5-16.5 | 4.0-7.0 | 3.0-4.5 | 2.5 max | 1.0 max | .01 max | .35 max | .04 max | .03 max | .08 max |
Mechanical Properties:
Product Form | Tensile (ksi) | .2% Yield (ksi) | Elongation % |
---|---|---|---|
Bar | 110.0 | 52.6 | 62 |
Plate | 107.4 | 50.3 | 67 |
Sheet | 115.5 | 54.6 | 60 |
Tube & Pipe | 105.4 | 45.4 | 70 |
Corrosion Resistance Properties:
Hastelloy C-276 is balanced to provide excellent corrosion resistance to a variety of chemical process environments. This alloy has provided resistance to hot contaminated mineral acids, organic and inorganic chloride contaminated media, hypochlorite, chlorine dioxide solutions, formic and acetc acids, acetic anhydride, sea water and brine solutions.
Typical General Corrosion Rates*
Environment | Concentration | Test | Penetration Rate (per year) | ||||||
°F | °C | Unwelded** | As-welded*** | Welded and | |||||
mils | mm | mils | mm | mils | mm | ||||
Formic Acid | 20 | Boiling | Boiling | 4.8 | 0.12 | 3.5 | 0.09 | 3.60 | 0.09 |
Heat-Treatment:
Wrought forms of Hastelloy C-276 are furnished in the solution heat-treated condition unless otherwise specified. Alloy C-276 is normally solution heat-treated at 2050 °F and rapid quenched. Parts which have been hot-formed should be solution heat-treated prior to final fabrication or installation, if possible.
Hastelloy C-276 products image: