Alloy 28 is a multipurpose stainless steel alloy characterized by high corrosion resistance in multiple environments, such as those containing strong acids and those that are stressful. It is utilized for its pitting and crack corrosion resistance properties, as well as its ability to withstand sulfuric and chloric acids. It displays higher levels of resistance to many caustic and corrosive substances and environments better than many other grades of stainless steels.
The chemical composition of Alloy 28 includes additions of both molybdenum and nickel. These serve to give Alloy 28 its resistance against acid attack on its structural integrity, along with increased ability to withstand high temperatures. However, it should be noted that damage can be caused if Alloy 28 is exposed to temperatures over 1110°F for extended periods of time. In spite of this, the metal shows great pliability to hot working practices when applied correctly.
Alloy 28 was originally manufactured for resistance against phosphoric acid, and now displays such resistance against a number of acids: sulfuric, chloric, and hydrochloric and hydrofluosilicic. It also shows nearly complete immunity against acetic acid and its corrosive effects.
Nuclear Industry