The Corrosion Behavior of Ni–Ta–5P Alloys in Concentrated Hydrochloric Acid

抄録

The addition of 30 at% or more tantalum to Ni–5P alloy greatly enhances the corrosion resistance in 12 M HCl at 30°C. The corrosion rate of amorphous Ni–40Ta–5P alloy is about three orders of magnitude lower than that of Ni–5P alloy. The addition of sufficient amounts of tantalum to Ni–5P alloys leads to an ennoblement of the open circuit potential and to spontaneous passivation. The addition of a large amount of tantalum to the Ni–Ta alloy contained a small amount of phosphorus, such as 5 at%, enhances the formation of the tantalum enriched passive film which prevents oxidation of phosphorus.