Titanium and titanium alloys are widely used in nuclear submarines, deep-sea submersibles, atomic icebreakers, hydrofoils, hovercrafts, 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 US deep-sea submersible "Haiya" is equipped with a titanium observation module and control module, and can dive to a depth of 6100m. China has also made great achievements in deep-sea submersible technology, with the independently designed "Jiaolong" submersible diving depth exceeding 5000m. But only Russia uses a large amount of 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 is at the forefront of international research and manufacturing technology in titanium alloy nuclear submarines, and was also the first country to use titanium alloy to build pressure resistant shells. During peak periods, 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 processed materials. Since the 1960s, Russia has developed four generations of nuclear submarines. The world's first all titanium nuclear submarine, K162, 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 subsequently built six more in the 1970s and 1980s, each using approximately 3000 tons of titanium and with a maximum diving depth of 914 meters. They are lightweight, fast, and have excellent maneuverability. A typical example of titanium used on ships is the Russian Typhoon class nuclear submarine, which has a titanium made outer shell. Due to military needs, a double shell structure is adopted, and the double-layer shell shares 9000 tons of titanium, making it non-magnetic, deep diving, fast speed, low noise, and requiring fewer maintenance times. The boat is 172.8m long, with a maximum width of 23.3m and a height of 42.7m. It has a water displacement of 232001 and a diving displacement of 33800t. The diving speed is 50km per hour, and the maximum diving depth is 500m. The continuous diving time reaches 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 Fujinobu Shipbuilding jointly built the "Mori Zhi Tian II" all titanium speedboat, which was very popular in the United States for a period of time. In 1997, the "Titan Rapid" speedboat manufactured by Nippon Kogyo Corporation was launched and set sail. It is about 12 meters long and has a beautiful three-dimensional curve, which can minimize navigation resistance. Jiangteng Shipyard manufactured two all titanium ships, the "Second Asahi Maru" and the "Akimaru", 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, and easy cleaning of attachments. The disadvantages are high material cost, difficult processing and manufacturing technology, and strict protection requirements. The results of the trial ship show good performance in terms of speed stability, vibration, and noise.
3. Deep diving vehicles, rescue boats, ship components
The United States, Japan, and France have all built deep-sea 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 the American Aivin and Sea Clifi deep-sea submersibles; Ti-6Al-4V ELI alloy is used for buoyancy balls on the French SM97, American Aivin, Japanese Deep Sea 2000, and US Navy Deep Sea Rescue Vessel (DSRV) shells and buoyancy balls.
4. Jiaolong submersible
The first independently designed and integrated manned submersible in China, the Jiaolong, 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 operations at a depth of 5180m. This diving depth means that the Jiaolong can reach over 70% of the world's seabed. The Jiaolong spacecraft is designed to have a depth of 7000m, which is the world's largest. It is expected to conduct a 7000m level sea trial in 2012. The scope of work covers 99.8% of the global ocean regions. China's manned deep-sea diving program is currently steadily advancing. The deep-sea submersible is the pinnacle of ocean technology development, similar to manned spaceflight engineering, reflecting a country's comprehensive technological strength. The activities of deep-sea manned submersibles cover the continental slope, mountaintops, volcanic craters, oceanic ridges, and the ocean floor, and have achieved a large number of research results in geochemistry, geophysics, and marine biology.
5. Sonar fairing
The titanium alloy sonar fairing has superior comprehensive performance and has been applied in the sonar systems of Russian ships such as the Kursk, Minsk, and Kiev. According to different requirements for underwater and surface applications, there are currently two types of shell plate acoustic materials used for sonar deflectors on Chinese naval vessels: stainless steel and fiber-reinforced fiberglass. During the Ninth Five Year Plan period, China conducted research on the application of titanium alloys in ship sonar deflectors.
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 bladed detachable supercavitating titanium alloy propeller on hydrofoils. 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 diameter that can be produced is 1200mm, and the fixed titanium alloy propeller with 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 naval vessels, due to extremely harsh working conditions, have a lifespan of only 2-5 years for pipelines made of copper and stainless steel. After replacement, the titanium alloy has a good effect and is suitable for high-speed seawater pipelines. The service life standard for Russian ship pipelines specifies three age requirements, namely the period for the first dock repair (8-9 years); The service life should not be less than 15 years; All levels of ships are required to operate reliably for 25-30 years throughout their entire lifespan.
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 unit 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.