The application of titanium in the field of ships

Titanium and titanium alloys are widely used in many fields due to their excellent properties. They are used in marine equipment such as nuclear submarines, deep-sea submersibles, nuclear-powered icebreakers, hydrofoils, hovercraft, and minesweepers, as well as propellers, whip antennas, seawater pipelines, condensers, heat exchangers, acoustic devices, and fire-fighting equipment.

Titanium pressure hulls play a crucial role in deep-sea submersibles. Both domestic and international manufacturers have applied titanium pressure hull technology to varying degrees. For example, the US's Sea Cliff submersible is equipped with a titanium observation and control module, allowing it to dive to a depth of 6100 meters. my country has also made significant achievements in deep-sea submersible technology, with its independently designed Jiaolong submersible reaching depths exceeding 5000 meters.

In the field of large submarines, Russia is the only country that uses titanium materials extensively. Its six Typhoon-class nuclear submarines primarily utilize various titanium alloys, including industrial pure titanium, Ti64, Ti64ELI, Ti-6Al-2Nb-1Ta-0.8Mo, Ti-3Al-2.5V, IIT-3B, and IIT-7M.

1. Nuclear submarine
Russia is a leader in the field of titanium alloy nuclear submarines, pioneering the use of titanium alloys to construct pressure hulls. Of its four generations of nuclear submarines since the 1960s, the K162, an all-titanium submarine launched in 1968, operated for over 30 years without incident. The ALFA-class nuclear submarine, built in 1970, has a maximum diving depth of 914 meters and excellent maneuverability. The Typhoon-class nuclear submarine employs a titanium double-hull structure, using 9,000 tons of titanium, and possesses advantages such as non-magnetic properties, deep diving depth, and high speed, with a maximum diving depth of 500 meters and a continuous submerged period of 120 days.

2. Full titanium boat‌
In 1985, Japan built the "Marishiten II" all-titanium speedboat, which sold well in the United States. In 1997, the "Titan Express" speedboat was launched, with optimized hull curves to reduce sailing resistance. Eto Shipbuilding built the "Second Asahi Maru" and "Sho Maru" in 1998-1999, which were lightweight, fast, and fuel-efficient, but costly and difficult to manufacture.

3. Deep-sea submersibles, rescue boats, and ship components
The United States, Japan, and France use titanium alloys to manufacture the pressure hulls of deep-sea submersibles. Ti-6Al-2Nb-1Ta-0.8Mo alloy is used for the hulls of the American Aivin and Sea-Clifi; Ti-6Al-4V ELI alloy is used for the hulls and buoyancy balls of the French SM97, the Japanese "Shinkai 2000", and the American Deep Sea Rescue Vehicle (DSRV).

4. Jiaolong submersible
my country's Jiaolong manned submersible, independently designed and integrated, completed its sea trial at a depth of 3,759 meters in 2010 and reached a depth of 5,180 meters in 2011, covering 70% of the global seabed. With a designed depth of 7,000 meters and an operational range covering 99.8% of the ocean area, it demonstrates the nation's comprehensive technological strength and promotes marine research.

5. Sonar fairing
Titanium alloy sonar fairings offer superior performance and are used in the sonar systems of ships such as the Russian "Kursk". The acoustic materials used for the sonar fairing shells of ships in service with the Chinese Navy are primarily stainless steel and fiber-reinforced fiberglass. During the Ninth Five-Year Plan period, my country conducted research on the application of titanium alloys in shipboard sonar fairings.

6. Propeller
Titanium alloy propellers are characterized by high strength, resistance to seawater erosion and cavitation corrosion, and can meet comprehensive performance requirements. The U.S. Navy was the first to use supercavitating titanium alloy propellers on hydrofoils. my country developed its own hydrofoil propellers in 1972 and has since produced titanium alloy propellers with diameters ranging from 450 to 1200 mm, boasting a service life more than five times that of copper alloys.

7. Ship pumps, valves and piping systems
Shipboard pumps, valves, and piping systems operate under harsh conditions; copper or stainless steel piping has a lifespan of only 2-5 years, while titanium alloy piping performs better. Russian regulations stipulate that shipboard piping should undergo its first maintenance every 8-9 years, have a service life of at least 15 years, and operate reliably for 25-30 years throughout its entire lifespan.

8. Atomic-powered ship
Russia has replaced stainless steel with titanium alloys in the manufacture of steam engines and heat exchangers, overcoming corrosion problems. Existing atomic-powered icebreakers widely use titanium steam engines, extending their service life by dozens of times.

Table 2-27 Usage of Titanium Steam Engines in Russian Atomic-Powered Icebreakers