The advantages of titanium for the ocean

The 21st world is called the century of the ocean. Marine space and resources have not only become an important field of increasingly fierce military and economic competition in the world, but also will become a strategic space and base for human survival, social development and the sustainable prosperity of coastal countries. In view of this, all coastal countries, especially naval powers, are vigorously developing naval equipment, marine security equipment and marine engineering equipment with the construction of sea power as the core.

Marine technology has entered the forefront of global scientific and technological competition, and has become one of the focuses of the competition of comprehensive strength among countries.  Different from land materials, sea related materials are used in the ocean, especially in the extreme environment of deep sea. They are subjected to heavy pressure or even high temperature of seawater, erosion and sulfide corrosion of marine microorganisms. They must have the characteristics of high strength, resistance to seawater hydrothermal corrosion, vulcanization corrosion, anti microbial adhesion and high toughness

Titanium metal is light, high-strength and corrosion-resistant, especially immune to the erosion of salt water or seawater and marine atmospheric environment. It is a high-quality light structural material, known as the third metal&marine metal&space metal&intelligent metal&the fourth generation metal. It is an important strategic metal material. Titanium is widely used in marine engineering, especially for light marine equipment. It is one of the new key materials in the field of marine engineering. Therefore, making full use of marine materials} titanium and titanium alloys will contribute to the development of national marine strategy.

Compared with common ferrous and non-ferrous metals, such as steel, copper and aluminum, titanium has the advantages of low density, high specific strength, strong corrosion resistance, no magnetism, no cold brittleness and high sound transmission coefficient. At the same time, it also has seawater erosion resistance, good process performance, good casting and welding performance, which makes it widely applicable to all kinds of marine engineering.

Titanium is a thermodynamically unstable metal, and its standard electrode potential is -1.63v. In the atmosphere or seawater, a protective oxide film will be formed on the surface of titanium immediately, making titanium in a passive state. Titanium is particularly resistant to chloride ion corrosion, so it is particularly resistant to the corrosion of seawater and marine atmosphere. Titanium can be used for all kinds of marine equipment or components that directly contact seawater and are exposed to the marine atmosphere, such as ship shell, sea pipeline, pump, valve, pipe joint, condenser, heat exchanger, seawater desalination device, offshore oil and gas production device, coastal bridge, etc.

Titanium is the material with the best resistance to normal temperature seawater corrosion among the known materials. It has good corrosion resistance even in polluted seawater, hot seawater (less than 120 ℃), sea mud and flowing seawater. Its excellent corrosion resistance is due to its good self passivation. When damaged to some extent, the surface oxide film or passivation film can be repaired and restored quickly. In other words, in the ocean, titanium is almost non corrosive. There is a strong and tough oxide film on the surface of titanium, so the corrosion resistance is higher than that of other metals. Titanium can be subject to stress corrosion only when it is in contact with dry salt at high temperature (about 315 ℃), so it is a very safe material in offshore engineering.

In the design of anti-corrosion equipment, the corrosion allowance in the thickness direction of bearing structural parts can be greatly reduced and the construction materials can be greatly saved; The anti-corrosion equipment can be designed with the same service life as the main body, reduce the maintenance frequency, greatly reduce the maintenance cost, and improve the service capacity of the equipment; It simplifies the manufacturing process of titanium and reduces the manufacturing cost without coating.