Caustic and Mixed Solvent Environments

Two entirely different types of environments are presented in this chapter. Caustic environments are encountered in chlor-alkali industry, production of various chemicals, hydrogen generation, and nuclear power production. Nickel is the most beneficial element for caustic environments. The effect of other elements and thermal treatments on corrosion and stress corrosion cracking in caustic environments is discussed. Corrosion in ammonia and ammonium hydroxide is discussed. The second type of environment is a mixed solvent (or non-aqueous) environment. The corrosion of Ni-base alloys in supercritical water used for oxidation of organics and power generation is reviewed. The effect of organic solvents on corrosion and stress corrosion cracking of Ni-base alloys is presented in terms of their aprotic and acid–base characteristics.