Titanium and titanium alloys are widely used in nuclear submarines, deep submersibles, atomic energy Icebreaker, Hydrofoil, Hovercraft, mine sweepers, propeller propellers, whip antennas, seawater pipelines, condensers, heat exchangers, acoustic devices, and fire-fighting equipment.

Titanium pressure hull is mainly used in deep-sea Submersible, and titanium pressure hull is used at home and abroad to varying degrees. For example, the US deep-sea vehicle 'Haiya' is equipped with a titanium observation module and control module, with a diving depth of up to 6100m. Great achievements have also been made in the technology of deep submersibles in China, with the self-designed "Jiaolong" submersible reaching a depth of over 5000m. But in the

Russia is the only country that extensively uses titanium on large submarines. Its six "Typhoon" nuclear submarines are mainly made of industrial pure titanium, Ti64, Ti64ELI, Ti-6Al-2Nb-1Ta-0.8Mo, Ti-3Al-2.5V, IIT-3B, IIT-7M, and other alloys.

1. Nuclear submarine

Russia holds an international position in the research and manufacturing technology of titanium alloy nuclear submarines, and is also a country that uses titanium alloy to build pressure resistant shells. During the peak period, the annual production of titanium alloy thick plates and pipes for submarines reached 10000 tons, accounting for 30% to 50% of the annual production of titanium alloy processing materials. Since the 1960s, Russia has developed four generations of nuclear submarines. The world's first K162 all titanium nuclear submarine was launched in December 1968 and has been in operation for over 30 years. It has traveled to various oceans, withstanding different loads and environments, and has never experienced any accidents. In 1970, Russia built * "ALFA" class nuclear submarines, and in the 1970s and 1980s, it successively built 6 more, each of which used about 3000t titanium and had a diving depth of 914m. They were both light and fast, with good maneuverability. A typical example of titanium used on ships is the Russian Typhoon class nuclear submarine, which has a shell made of titanium metal. Due to military needs, it adopts a double shell structure, and its double shell shares 9000 tons of titanium, making it non magnetic, deep diving, fast sailing speed, low noise, and less maintenance. The submarine has a length of 172.8m, a width of 23.3m, a height of 42.7m, a displacement of 232001 on water, a displacement of 33800t underwater, a diving speed of 50km/h, a diving depth of 500m, and a continuous diving time of 120 days. The boat was built in 1977 and put into service in 1981. It plays an important role in the Russian Navy.

2. All titanium ship

In 1985, Japan Tobon Titanium Corporation and Fujitsu Shipyard jointly built the "Marichi TianII" all titanium speedboat, which was very popular in the United States for a period of time. In 1997, the "Titan Express" speedboat manufactured by Nissan Industries was launched and set sail, with a captain of about 12 meters. The hull shape is a beautiful three-dimensional curve, which can reduce navigation resistance. Jiangteng Shipyard built two all titanium ships, the "Second SS Dante Alighieri" and the "Zhaowan", in 1998 and 1999 respectively. The advantages are light weight, fast speed, small engine, low fuel cost, low carbon dioxide emissions, no need for surface coating, easy to clean attachments, etc. The disadvantages are high material cost, difficult processing and manufacturing technology, and strict protection requirements. The results of the ship trial show that the stability of the ship's speed, vibration, and noise are all very good.

3. Deep submersibles, rescue boats, and ship components

The United States, Japan, and France have all built deep submersibles, using titanium and titanium alloys to manufacture pressure resistant shells. Among them, Ti-6Al-2Nb-1Ta-0.8Mo alloy is used to manufacture the shells of American Aivin and Sea Clifi deep submersibles; Ti-6Al-4V ELI alloy is used for buoyancy balls of the French SM97, American Aivin, Japanese "Deep Sea 2000", and shells and buoyancy balls of the US Navy Deep Sea Rescue Vehicle (DSRV).

4. Jiaolong Submersible

The Jiaolong, China's first independently designed and integrated manned Submersible, is shown in Figure 2-1. The 3759m sea trial was completed in July 2010, and on August 1, 2011, the Jiaolong officially began its underwater operation at a depth of 5180m. This diving depth means that the Jiaolong can reach over 70% of the global seabed. The design depth of the Jiaolong spacecraft is 7000m of the world's *, and it is expected to conduct a 7000m level sea trial in 2012. The scope of work covers 99.8% of global marine areas. China's manned deep diving program is currently steadily advancing. Deep submersibles are the commanding heights of marine technology development. Similar to the Human spaceflight project, they reflect a country's comprehensive technical strength. Deep sea manned Submersible have activities all over the Continental margin, seamounts, craters, ridges and ocean floor. They have made a lot of research achievements in geochemistry, geophysics and marine biology.

5. Sonar deflector

The titanium alloy sonar dome has excellent comprehensive performance and has been used in the sonar systems of Russia's "Kursk", "Minsk", "Kiev" and other warships. According to the different requirements for underwater and surface applications, there are basically two types of shell plate sound transmission materials used for the sonar fairing of naval vessels in service in China, one is stainless steel, and the other is fiber-reinforced fiberglass. During the Ninth Five Year Plan period, China carried out research on the application of titanium alloy in ship sonar fairs.

6. Propeller

The propeller material requires high strength, good fatigue performance in seawater medium, resistance to erosion and cavitation corrosion, and titanium alloy can meet the above comprehensive performance requirements. The US Navy first used a four blade detachable supercavitating titanium alloy propeller with a diameter of 1500mm on hydrofoil vessels. China developed hydrofoil speedboat propellers in 1972 and has produced various types of titanium alloy propellers with diameters ranging from 450 to 1100mm. Fixed titanium alloy propellers with a diameter of 1200mm and a mass of 130kg can be produced. Long term use has shown that the service life of titanium alloy propellers is more than five times that of copper alloy propellers.

7. Shipboard pumps, valves, and piping systems

The pumps, valves, and pipes on ships have a lifespan of only 2-5 years for pipelines made of copper and stainless steel due to extremely harsh working conditions. After replacement, titanium alloy has a good effect and is suitable for high flow rate dynamic seawater pipelines. The service life standards for ship pipelines in Russia stipulate three service life requirements, namely the period for * times of dock maintenance (8-9 years); The service life should not be less than 15 years; The full life requirement is that all levels of ships should operate reliably over a period of 25-30 years.

8. Atomic powered ship

Russia used titanium alloy instead of stainless steel to manufacture steam engines, heat exchangers, and coolers for ships, overcoming corrosion damage. Titanium steam engines are widely used in the power plants of Russia's existing atomic powered Icebreaker. The use of titanium alloy can extend the service life of its engine by tens of times or more.