Austenitische gegen Spannungsrißkorrosion in konzentrierten Chloridlösungen beständige Manganchromstähle

Austenitic manganese chromium steels resistant to stress corrosion cracking in concentrated chloride solutions The testing of stress corrosion susceptibility in MgCl₂ and CaCl₂ shows that the classical Austenitic CrNi and CrMnNiN steels are not sufficiently resistant to this type of corrosion. On the other hand MnCr steels exhibit good resistance even in hot solutions. The resistance, however, is considerably deteriorated by addition of Ni even in small quantities; with Ni contents up to 0.5%, however, the time to failure is still considerable. This fact is important since such nickel contents must be counted with because of production conditions in metallurgy. On the basis of experiments including investigation into mechanical properties, microstructure, metallic phases present and stress corrosion resistance (under constant tensile load) in MgCl₂ solution (35%, 115–120 °C) the authors selected out of 62 types of steels tested four experimental austenitic MnCr steels meeting the following complex of requirements: high resistance in MgCl₂ solution, sufficiently high resistance to intercrystalline corrosion, certain resistance to pitting and practically monophasic (austenitic) structure.