Commercially pure wrought Nickel has been known for good mechanical properties over a wide range of temperatures, and an excellent resistance to many corrosives, in particular hydroxides.
Nickel has a strong resistance to corrosion in acids and alkalis, and is most useful under reducing conditions; it also has great resistance to caustic alkalis up to and including the molten state. In acid, alkaline and neutral salt solutions, the material shows good resistance, but in oxidizing salt solutions severe attacks will occur.
Nickel is also resistant to all dry gases at room temperature, and dry chlorine and hydrogen chloride may be used in temperatures up to 550°C. Resistance to mineral acids varies according to temperature and concentration and whether the solution is aerated or not. Corrosion resistance is better in de-aerated acid.
Image credit: High Performance Alloys, Inc.