"Acid gas corrosion"

Question:

"We are desperately trying to find a material to suit an application that is in contact with these vapours: Steam (sat 350F),HCl, h3SO4, Isopropyl-alcohol,Bromines, Amines, Nitric Acid, Phosphoric Acid, Acetic Acid, Butyric Acid, Various organic solvents. (proportions unknown, mostly steam and air, the other gases are small). Overall temp = 350F max, no pressure. SS, titanium and hastelloy C276 do not work. C276 had severe pitting corrosion. The steam component means that plastics do not work. Inert ceramics do not corrode, but again the steam damages the brittle ceramics with thermal effects. It is not an easy problem, but I would appreciate some pointers in the right direction. I can find very little information of bromides causing corrosion. We would run lab tests if possible to see how different materials behave."

Answer:

You don't state what equipment you are interested in. The type, geometry and configuration of process components plays a large role in materials selection. However, based on the environment you stated, you might consider the teflon family (as a coating) and zirconium. Borosilicate glass and graphite may also be candidates, depending on the specific components involved. Alloys C-22 and C-2000 may also offer increased pitting resistance over C-276. Alloy B-2 might be considered; however, the oxidizing components probably will negate this alloy. We can help test potential candidates if you need.

<< return to the previous page ::