Corrosion behavior of niobium, tantalum and their alloys in hot hydrochloric and phosphoric acid solutions

摘要

The corrosion resistance of niobium, tantalum and Nb-20, 40, 60 and 80 wt percent Ta alloys in 5, 10, 15 and 20 wt percent HCl and 20,40, and 80 wt percent H_3PO_4 solutions at boiling point, 150deg C and 200deg C is evaluated using the mass-loss technique. The corrosion rates of materials increase with acid concentration and temperature. At boiling point the corrosion rates diminish with time but for long Sure time, they tend to stabilize due to the formation of superficial oxides. The corrosion resistance increases with tantalum content. The iso-corrosion curves of niobium, tantalum and Nb-Ta alloys in 5-20 wt percent HCI and 20-80 wt percent H5P04 up to 200deg C are m from interpolation of the measured corrosion rates.