Titanium has been widely used in surface ships, underwater submarines, submersibles, underwater weapons and communications equipment, and so on.

The results show that titanium has a good resistance to seawater corrosion. After 5 years of natural static water corrosion test, titanium has no stress corrosion tendency and no crevice corrosion in natural seawater. The resistance of titanium to scour corrosion is also very strong. Contrastive tests show that nickel alloy has poor scour corrosion resistance at a velocity greater than 5m/s, while titanium alloy remains intact at a velocity higher than 7m/s and 10m/s. Chloride ions in seawater are difficult to destroy the passivation film on the surface of titanium alloy, so they are not prone to spot corrosion, Gap corrosion and stress corrosion such as stainless steel and aluminum.

Chloride ions in seawater are difficult to destroy the passivation film on the surface of titanium alloy, so they are not prone to spot corrosion, Gap corrosion and stress corrosion such as stainless steel and aluminum. In addition, unlike stainless steel, the welding and cold processing of titanium alloys do not lead to changes in titanium corrosion resistance. According to the problem of marine organism attachment, the practical investigation of submarine marine system pipeline shows that marine life grows very little and no marine life grows in the main loop water system.

The United States, Japan and Russia have successfully used titanium on submersible vehicles, bringing the depth to 5,000, 6,000 and 6,500 meters, respectively. Russia is the country that uses the most titanium material in nuclear submarines, the most typical of which is the all-titanium nuclear submarine, which uses 9,000 tons of titanium material per boat. Titanium is used in condensers, heat exchangers, Sonar guides, pipelines and bellows. Diesel engine gas exhaust system, Sonar guide cover, pipeline system, bellows, pumps and valves in conventional submarines are also extensively used titanium. Titanium is also widely used in Russian missile destroyers, aircraft carrier sonar guide systems, pipeline systems, bellows, pumps and valves. Its main vessels have been tested by global sea navigation in the Arctic, Antarctic, Equator, Pacific, Indian Ocean and Atlantic Ocean, and have solved the problems of design allowable stress and safety coefficient selection.

Titanium materials are also used in the water jet propulsion system of various vessels in the United States and Japan, which can effectively overcome the adverse effects of cutting the Earth's magnetic field line with copper alloy. The use of titanium alloy instead of Cr-Mo alloy steel in the North Sea oil field in the UK has reduced quality and maintenance costs by 40 %. They used 30 tubes measuring 609mm X 25mm X 1460mm in a single tube to form a 400-metre long, 900-ton tubing for an oil recovery system at 350 metres deep.

A large number of international application examples have proved that titanium and titanium alloys are undoubtedly suitable for use in seawater conditions, a case in point is the Russian naval equipment in a large number of titanium alloys and successfully tested in practical applications. At present, the production level of titanium in our country is similar to that in other countries. The development of titanium industry in our country can meet the requirement of large-scale use of titanium in naval engineering. In order to build a strong Navy for our motherland, we should lead the coordination and cooperation of various departments with scientific development, raise the level, reduce the cost, and popularize titanium in naval engineering as soon as possible.