Titanium has strong corrosion resistance in alkali and alkaline media. Both sodium hydroxide, potassium hydroxide, ammonia, calcium hydroxide, and magnesium hydroxide are very corrosion resistant. The corrosion rate of titanium in boiling saturated calcium hydroxide, magnesium hydroxide, and ammonia water is almost 0. In high temperature and high concentration sodium hydroxide solution, such as 50%~73% solution at 188 ℃, the corrosion rate may exceed 1 09mm/a。 Nevertheless, the hydrogen embrittlement sensitivity of titanium in the high-temperature alkaline solution cannot be ignored. When the temperature exceeds 77 ℃ and the pH value of the alkali solution is greater than 12, special attention should be paid to the possibility of hydrogen absorption and hydrogen embrittlement of titanium in the alkali solution.
