General corrosion resistance

Nickel alloys offer particularly useful corrosion-resistant solutions when stainless steels can no longer be used economically. It is generally accepted that a metallic material is resistant to generalized corrosion when its corrosion rate in the medium under consideration is less than 0.1 mm/yr. (Unless criteria of non-pollution of the medium are paramount.) In very difficult cases, a user may accept up to 0.5 mm/yr. It is, of course, impossible to report here on all the properties of all nickel alloys. The aim of this article is to show that there are solutions for media recognized as particularly corrosive, such as sulfuric acid, halogenated acids, nitric acid, organic acids, caustic media, salts and seawater. Producers of nickel alloys evaluate the corrosion resistance of their products by means of laboratory tests. These provide valuable information on the performance of the alloys....