Titanium and titanium alloys are widely used in nuclear submarines, deep submersibles, atomic energy icebreakers, hydrofoils, hovercraft, minesweepers, as well as propeller propellers, whip antennas, seawater pipelines, condensers, heat exchangers, acoustic devices, and firefighting equipment.

Titanium pressure resistant shells are mainly used in deep-sea submersibles, and titanium pressure resistant shells are used to varying degrees both domestically and internationally. The American deep-sea submersible "Haiya" is equipped with a titanium observation module and control module, with a diving depth of up to 6100m. China has also achieved great success in deep submersible technology, with the self-designed Jiaolong submersible reaching a depth of over 5000m. But 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, etc.

1. Nuclear submarine

Russia is at the forefront of international research and manufacturing technology for titanium alloy nuclear submarines, and was also the first country to use 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, withstood different loads and environments, and has never experienced any accidents. Russia built its first ALFA class nuclear submarine in 1970, and in the 1970s and 1980s, it built six more, each with approximately 3000 tons of titanium. The maximum diving depth is 914 meters, which is both light and fast, and has 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, giving it advantages such as non-magnetism, deep diving, fast sailing speed, low noise, and few maintenance times. The submarine has a length of 172.8 meters, a maximum width of 23.3 meters, a height of 42.7 meters, a water displacement of 232001, a diving displacement of 33800 tons, a diving speed of 50 kilometers per hour, a maximum diving depth of 500 meters, and a continuous diving time of 120 days. The ship started construction in 1977 and entered service in 1981, playing a crucial role in the Russian Navy.

2. All titanium ship

In 1985, Japan's Toho Titanium Company and Fujishin Shipyard jointly built the "Molitshita II" all titanium speedboat, which was 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 length of about 12 meters. The hull shape is a beautiful three-dimensional curve, which can minimize navigation resistance. The Jiangteng Shipyard manufactured two all titanium ships, the "Second Asahi Maru" and "Zhaomaru", in 1998 and 1999 respectively. The advantages of these ships are light weight, fast speed, small engine, low fuel cost, low carbon dioxide emissions, no need for surface coatings, and easy cleaning of attachments. The disadvantages are high material costs, difficult processing and manufacturing technology, and strict protection requirements. The results of the trial ship show that the ship has good performance in terms of speed stability, vibration, and noise.

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 in French SM97, American Aivin, Japanese Deep Sea 2000, and the shells and buoyancy balls of US Navy Deep Sea Rescue Vehicles (DSRVs).

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 world's seabed. The design depth of Jiaolong is the world's highest at 7000m, and it is expected to conduct sea trials at a depth of 7000m in 2012. The scope of work covers 99.8% of global ocean regions. China's manned deep diving program is currently steadily advancing. Deep submersibles are the pinnacle of ocean technology development, similar to manned spaceflight engineering, reflecting a country's comprehensive technological strength. The activity range of deep-sea manned submersibles covers continental slopes, seamounts, volcanic craters, ocean ridges, and the ocean floor, and has achieved a lot of research results in geochemistry, geophysics, and marine biology.

5. Sonar fairing

The titanium alloy sonar dome has superior comprehensive performance and is applied in the sonar systems of Russian ships such as Kursk, Minsk, and Kiev. According to the different requirements for underwater and surface applications, there are basically two types of shell plate sound transmitting materials used in the sonar fairings of in-service naval vessels 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 fairings.

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 1500mm diameter, four blade detachable supercavitating titanium alloy propeller on hydrofoil boats. China developed hydrofoil speedboat propellers in 1972 and has since produced various types of titanium alloy propellers with diameters ranging from 450 to 1100mm. The maximum production capacity is fixed titanium alloy propellers with a diameter of 1200mm and a mass of 130kg. Long term use has shown that the service life of titanium alloy propellers is more than 5 times that of copper alloy propellers.

7. Ship pumps, valves, and piping systems

The pumps, valves, and pipes on ships, due to extremely harsh working conditions, have a lifespan of only 2-5 years for pipes made of copper and stainless steel. After replacement, titanium alloy has a good effect and is suitable for high-speed seawater pipelines. The service life standards for ship pipelines in Russia stipulate three service life requirements, namely the first maintenance period in the shipyard (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 for a period of 25-30 years.

8. Atomic powered ship

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