Making the grade

News and developments in the world of corrosion resistant alloys through the eyes of Corrotherm International

INCONEL alloy C276 – one for the tough environment

10 February 2021


In extreme environments containing aggressive acids and other corrosive media, nickel alloys really need to work hard. INCONEL alloy C-276 is a popular option in even the toughest of conditions. We look at why

When it comes to selecting the right material for use in tough industrial environments, there are a number of factors to take into consideration. You need to know what kind of corrosive media will be present, what the operating temperature range is and what load the material will be under. In the harshest of situations, materials will need to be capable of performing in some of the most corrosive conditions on earth, at elevated temperatures and under high pressure.

Finding an alloy that can survive in such an extreme environment is not an easy task. INCONEL alloy C-276 is one material that is worth considering, thanks to its exceptional corrosion resistance to a wide range of aggressive media. It is used across a number of different industrial applications and is considered one of the most versatile options for tough environments.

It is resistant to general corrosion, such as stress-corrosion cracking, pitting and crevice corrosion. It’s also resistant to sulfuric, hydrochloric and phosphoric acids; highly oxidising, neutral and acid chlorides; and solvents, formic and acetic acids, acetic anhydride, wet chlorine gas, hypochlorites and chlorine solutions. It is also resistant to carbide precipitation during welding – which maintains its corrosion resistance in the heat-affected zones of welded joints – as well as seawater.

Key applications

With such a broad range of resistant properties, it’s no wonder that INCONEL alloy C-276 is used in so many applications.

For example, it is used in flue gas desulfurisation (FGD) systems to control the air pollution from electric power plants. The components it is used for includes scrubbers, ducting and stack liners. In comparison to other alloys, INCONEL alloy C-276 has been shown to have the ability to withstand a higher chloride content before the onset of localised corrosion. Given that scrubber liquids and gas condensates contain chlorides, it’s no wonder this is a go-to option in this industrial sector.

This nickel alloy is also chosen for use in some oilfield applications. When it comes to the recovery and handling of sour natural gas – which often contains hydrogen sulphide, carbon dioxide and chlorides – materials need to have good resistance to sulphide stress cracking and stress-corrosion cracking. INCONEL alloy C-276 has high levels of nickel, chromium and molybdenum, which work together to provide this resistance, even at high temperatures in deep wells. It’s used for things like tubing, and downhole and surface components.

Its compositional makeup is also useful in pollution control and waste processing, which is a very tough environment. The high molybdenum content helps to form a resistance to pitting and crevice corrosion. When it comes to air pollution control, the alloy is used for stack liners, ducts, dampers, scrubbers, stack-gas re-heaters, fans and fan housings.

INCONEL alloy C-276 is also an important material in chemical processing. It has been selected for use in processes that contain ferric and cupric chloride ions, chlorine, hypochlorite, chlorine dioxide, organic acids, acetic anhydride, seawater, brine and sour oil and gas wellhead fluids. It is used for things like heat exchangers, reaction vessels, evaporators and transfer piping.

You can view the details and properties of INCONEL alloy C-276 on its dedicated product page. To find out more about any of the nickel alloys that Corrotherm supplies, see our Contact Page to get in touch.


Published in Corrotherm News