Basic properties:
Melting point: 2468 ° C
Boiling point: 4742°C
Water soluble: Insoluble in water
Density: 8.57 g / cm 3
Chemical properties of niobium:
At lower temperatures, the reaction of niobium with oxygen increases the thickness of the surface oxide film, forming a protective oxide film, and the oxidation rate is slowed down, and the reaction is parabolic.
Reaction of niobium with other gases:
Gases | Temperature/℃ | Chemical behavior |
H | ＞300 | Hydrogen absorption becomes brittle |
N | ＞700 | Nitrogen absorption becomes brittle |
NH3 | ＞700 | Dissolving and becoming brittle |
Carbohydrate | 800~1000 | carburization |
Corrosion resistance of niobium in chemical media:
At room temperature, it is very stable in many inorganic salts, organic acids, mineral acids, and aqueous solutions, but its alkali resistance is poor. The mixed acid of hydrofluoric acid, hydrofluoric acid and nitric acid can erode niobium. The acid resistance of niobium decreases at temperatures above 100 °C.
