Titanium alloys are widely used in various fields because of their high strength, good corrosion resistance, and high heat resistance. many countries in the world
All recognize the importance of titanium alloy materials, have successively carried out research and development on them, and have been practically applied. Titanium alloys in marine applications
It has great development potential. The following describes the application of titanium alloys on ships:
1. Application in ship structure
Although titanium and titanium alloys have high yield strength, they require inert gas protection during welding, which is more difficult to form than steel. Therefore, ordinary water
Surface ship structures rarely use titanium. Titanium and titanium alloys are mainly used in submarines, submersibles, and other ships to cope with the simultaneous impact on yield strength and density.
and occasions where high corrosion resistance is required.
my country developed Ti80 titanium alloy in the 1980s, which is used to manufacture the pressure-resistant shell of deep submersibles and submarines.
Toughness, corrosion resistance, weldability, and other excellent properties, under the conditions of tensile strength 880~925MPa, yield strength 785~885MPa, fracture
Toughness and stress corrosion resistance is significantly better than Ti6AI4VELI alloy. The Ti91 titanium alloy developed in the 1990s has a yield strength of
700MPa.
2. Used for ship coolers
Because titanium and titanium alloys have better corrosion resistance than other alloys in seawater and have higher strength than commonly used copper alloys,
The density is low, and the heat transfer efficiency can be ensured by reducing the thickness of the tube wall and increasing the flow rate of seawater. Reliability of safe operation of equipment in nuclear submarines
There are high-demand application fields, the application of titanium heat exchangers is very important.
At present, the most widely used industrial pure titanium in the United States is industrial pure titanium, which has special resistance to natural water, seawater, and various chlorides.
ability to corrode. In desalination equipment with a seawater flow rate of 3~5m/s, the fouling coefficient of the titanium heat exchanger is only 0.95~0.99. my country
It has also successfully developed some titanium alloys with excellent performance, such as Ti31 titanium alloys, which are used for waste heat discharge coolers, pipelines, etc. The working environment is
High-temperature seawater or normal temperature high-speed seawater, resistant to high-temperature corrosion of 180℃.
3. Used for ship pipelines
Due to the direct contact with the seawater and most of them are arranged in the bilge, the working environment of the ship's sea system pipeline is harsh, and corrosion has always restricted its development.
Prominent issues to maximize performance. In the 1970s, my country successfully developed TA5α-type titanium alloy (Ti-4Al-0.05B), which has relatively high strength.
High, the yield strength of as-cast ZTiAI4 is not less than 490MPa, which can be used in the manufacture of pumps and valves in marine auxiliary systems. Research in the 1980s
The Ti75 titanium alloy made of the TA5 alloy has a strength improvement of 50MPa under the premise of good comprehensive properties, and the impact toughness and fracture toughness are respectively 1.4 of that of TA5.
times and 1.2 times, the stress corrosion fracture toughness is 2 times that of TA5, and has excellent cold and hot workability, casting performance, and low impurity sensitivity
sex. Ti75 titanium alloy fills the blank of domestic 730MPa marine titanium alloy and reaches the international advanced level. Reciprocating made of Ti75 alloy
Type saltwater pump, side double seat double ball valve stem have been used normally.
4. For ship propellers
Titanium alloy has high strength, is lightweight, has excellent resistance to cavitation erosion and fatigue resistance, and is an ideal material for manufacturing propellers. use
The life of the propeller made of ZTi6AI4V is 3 times that of the copper alloy propeller. my country began to develop ZTi6AI4V alloys in the late 1960s.
Research work was successfully applied to hydrofoil propellers in the 1970s. After 20 years of real boat verification, the performance is good.
In addition, the high-strength cast titanium alloy with better welding performance, higher toughness, and better anti-cavitation erosion performance developed in my country has been successfully developed.
At present, it has been used in the manufacture of a hydrofoil speedboat propeller.
