Although titanium and titanium alloys have high yield strength, they require inert gas protection during welding and are more difficult to form than steel. Therefore, titanium is rarely used in general surface ship structures. Titanium and titanium alloys are mainly used in submarines, deep submersibles and other ships to cope with situations that require high yield strength, density and corrosion resistance.
Ti80 titanium alloy is used to manufacture pressure-resistant shells of deep submersibles and submarines. It has excellent properties such as high strength, high toughness, corrosion resistance, and weldability. Under the conditions of tensile strength 880~925MPa and yield strength 785~885MPa, The fracture toughness and stress corrosion resistance are significantly better than Ti6Al4VELI alloy. The Ti91 titanium alloy developed in the 1990s has a yield strength of 700MPa.
Since titanium and titanium alloys have better corrosion resistance than other alloys in seawater, and have higher strength and lower density than commonly used copper alloys, heat transfer efficiency can be ensured by thinning the tube wall thickness and increasing the seawater flow rate. In applications such as nuclear submarines that have high requirements for the safe operation and reliability of equipment, the application of titanium heat exchangers is highly valued.
