Titanium Corrosion Resistance

Titanium is a very active metal with a very low equilibrium potential and a high tendency to thermodynamic corrosion in media. However, titanium is actually stable in many media, such as titanium is corrosion resistant in oxidizing, neutral and weakly reducing media. This is because titanium and oxygen have a great affinity, in the air or oxygen-containing media, titanium surface to generate a layer of dense, strong adhesion, inert oxidized film, protecting the titanium substrate from corrosion. Even due to mechanical wear and tear will soon self-heal or regenerate. This shows that titanium is a metal with a strong passivation tendency. Medium temperature below 315 ℃ titanium oxide film always maintain this characteristic.

In order to improve the corrosion resistance of titanium, surface treatment techniques such as oxidation, electroplating, plasma spraying, ion nitriding, ion implantation and laser treatment have been investigated, which play an enhanced protective role on the oxide film of titanium, and the desired corrosion resistance effect has been obtained. In response to the need for metal materials in the production of sulfuric acid, hydrochloric acid, methylamine solution, high-temperature wet chlorine gas and high-temperature chlorides, a series of corrosion-resistant titanium alloys, such as titanium-molybdenum, titanium-palladium, titanium-molybdenum-nickel, etc., have been developed. Titanium castings using titanium-32 molybdenum alloy, often occurring crevice corrosion or pitting corrosion of the environment using titanium-0.3 molybdenum-0.8 nickel alloy or titanium equipment, local use of titanium-0.2 palladium alloy, have obtained very good results.