Corrosion resistance of zirconium in other media

 

 

 

Corrosion resistance of zirconium in other media

 

Under the high temperature and high pressure urea synthesis conditions, zirconium is extremely corrosion-resistant.

 

Zirconium also has good chemical stability in many chemical polymers, azo dyes, and ethanol production media. For example, in the test of heat transfer media, including mixed materials such as chlorinated biphenyl and cumene, the corrosion rate of zirconium was zero in all cases. But if hydrogen is present in the medium, zirconium will absorb hydrogen. If the medium contains water, ensuring the integrity of the oxide film on the zirconium surface will reduce hydrogen absorption.

 

Zirconium is not corroded by most gases (CO, CO2, SO2, C3H8, N2, water vapor and steam) at 300~400°C. When zirconium is heated to 425°C in air, it will peel severely.

 

It reacts with oxygen at 540°C to form white zirconia. Above 704°C, zirconium absorbs hydrogen and becomes brittle. Heated to 1000℃, it will become natural. In a nitrogen atmosphere, zirconium begins to react slowly at 400°C and reacts violently after 800°C.

 

Vacuum annealing cannot remove oxygen and nitrogen in zirconium. Hydrogen is easily soluble in zirconium, and the solubility increases sharply as the temperature increases. Zirconium begins to absorb hydrogen relatively at 300~400℃.

 

After absorbing hydrogen, it causes "hydrogen embrittlement" of zirconium. However, hydrogen can be eliminated by vacuum annealing at 1000°C. Zirconium has a greater affinity with oxygen, nitrogen, and hydrogen and is similar to titanium.