When equipment manufacturers and users face corrosion problems caused by chlorine and chlorine compounds, they will find titanium's resistance properties useful over a wide range of temperatures and concentrations.
In most oxidizing, neutral and inhibiting reducing conditions, titanium and its alloys have excellent corrosion resistance. Although they may be attacked by strong reducing or complexing media, they also remain passivated under mild reducing conditions. The corrosion resistance of titanium metal is due to a stable, protective and highly adhesive oxide film. This film forms immediately when a fresh surface is exposed to air or moisture. From the experts’ words, when the clean surface of titanium is exposed to air, the oxide film would be formed soon. The thickness is about 12-16 angstroms.About 50 angstroms after 70 days. It continued to grow slowly, reaching a thickness of 80-90 angstroms after 545 days and 250 angstroms after four years. Film growth is accelerated under strong oxidizing conditions, such as heating in air, anodic polarization in an electrolyte, or exposure to oxidizing agents such as hyponitric acid, chromic acid, etc. The composition of the films ranges from surface TiO2 to Ti2O3 to TiO2. The oxidation conditions promote the formation of titanium dioxide, so in this environment, the film is mainly titanium dioxide. The film is transparent in its normal thin structure and cannot be detected by visual means. When we study the corrosion resistance of titanium, basically we just need to study the properties of oxide film.The oxide film on titanium is very stable. It is just attacked by only a few substances, most notably hydrofluoric acid. In any environment where trace amounts of moisture or oxygen are present, titanium repairs this film almost immediately because of its strong affinity for oxygen. Use in the absence of oxygen and water should be avoided as the protective film may not regenerate if damaged.
Titanium is unique among metals in handling these environment,where titanium is not be corroded by aqueous solution of chlorine and chlorine compounds.Variety of titanium applications are based on the corrosion resistance of titanium in moist chlorine gas and chloride containing solutions. Titanium is widely used in chlor-alkali cell, dimensionally stable anodes, bleaching equipment for pulp and paper, and in heat exchangers, pumps, pipes and vessels for the production of organic intermediates and pollution control devices.
Chlorine gas
Titanium is widely used to handle moist chlorine and has a great reputation for its excellent performance in this service. The strong oxidizing properties of moist chlorine passivate titanium, which makes the corrosion rate of titanium in moist chlorine low.
Dry chlorine can attack titanium rapidly and even lead to iginate while the moisture content is low enough. However, 1% water is usually sufficient to passivate or repassivate titanium after mechanical damage in chlorine under static conditions at room temperature. How much moisture content require in actual, is affected by the gas pressure, gas flow and temperature, as well as mechanical damage to the oxide film on titanium. Passivation apparently requires about 1.5% moisture at 390°F (199°C). Care should be taken when using titanium in chlorine with low moisture content.
Chlorine chemicals
In the solutions of chlorine dioxide, chlorite, sodium hypochlorite, chlorate, and perchlorate, titanium is fully resistant. Titanium equipment has been used in the pulp and paper industry to handle these chemicals for many years without any signs of corrosion. (5) Titanium is used today in almost all equipment in modern bleach plants that handle wet chlorine or chlorine chemicals, such as chlorine dioxide mixers, pipes, and washers. In the future, these applications are expected to expand, including the use of titanium in chlorine dioxide generators and wastewater recovery equipment.
Chloride
In neutral chloride solutions, even at relatively high temperatures, titanium also has an excellent performance in corrosion resistance. Titanium typically exhibits very low corrosion rates in chloride environments. However, sometimes titanium and its alloys are limited use in aqueous chloride environments due to crevice corrosion. When crevices have occurred, titanium sometimes corrodes and the general corrosion rate cannot be predicted. Our research shows that pH and temperature are important variables for crevice corrosion in brine.
Titanium products;
Heat exchanger /storage tank/ condenser / radiator
Dimensional stable anode
Titanium piping / pump/ fittings / flanges
Titanium vessels
Titanium venturi scrubber
For more details, please click the below links;
Sodium Hypochlorite Storage Tank
Titanium Storage Tank For Sodium Hypochlorite
Titanium Flanges For Storage Tanks
Titanium Centrifugal Pump For Sodium Hypochlorite
Welded Titanium Pipe For Sodium Hypochlorite
Heat Conducting Pipe in Seawater Desalination Equipment
Titanium Tube Evaporators Case In Multistage Flash (MSF)
Seawater Desalination Equipment Introduction
Corrosion Mechanism Of Seawater Equipment
Titanium Is The Best Material For Heat Exchangers Of Seawater Desalination Equipment