Investigating the crevice corrosion of 304 stainless steel and B30 copper-nickel alloys by thiosulfate using wire beam electrode Untersuchung der Spaltkorrosion von rostfreiem Stahl 304 und Kupfer-Nickel-Legierungen B30 durch Thiosulfat unter Verwendung einer Drahtstrahlelektrode

Crevice corrosion behavior of 304 stainless steel and B30 copper-nickel alloys in sodium chloride solution containing different concentrations of thiosulfate ion (S₂O₃²⁻) were studied by wire beam electrode. The increase of thiosulfate ion concentration promotes the crevice corrosion of 304 stainless steel. However, the crevice corrosion is inhibited due to excess thiosulfate ions. The local corrosion intensity inside and outside the crevice also formed an inversion at the chloride ion (Cl⁻)/thiosulfate ion concentration ratio. When coupled 304 stainless steel and B30 copper-nickel alloy occurs crevice corrosion, 304 stainless steel outside the crevice acts as the cathode and B30 copper-nickel alloy acts as the anode at the initial stage. The active dissolution of 304 stainless steel inside and outside the crevice jointly promoted the crevice corrosion of B30 copper-nickel alloy at the later stage. The crevice corrosion mechanisms of 304 stainless steel and B30 copper-nickel alloy are also discussed.