An Investigation of Corrosion of Titanium Heat Exchanger in Strongly Acidic Hot-spring Water

Abstract

We investigated corrosion behavior of titanium heat exchangers (THEs) in strongly acidic (pH=1.6) hot-spring water. Some THEs showed high corrosion rate, the others showed no-corrosion, despite contacting the same hot-spring water. The THEs showed high corrosion rate have been used in heavy heat cycle. Therefore, a heavy heat cycle could accelerate corrosion of titanium in actual environment.
On the other hand, at least two types of titanium have been distributed in Japan. One has titanium carbide in its surface and the other hasn't it. We should care about the manufacturing history of received titanium plates when we assemble titanium heat exchanger, since the existence of the titanium carbide in the surface of titanium could affect corrosion behavior of titanium.