China's marine strategy development is "titanium" is strong
The 21st century is known as the century of the ocean. Marine space and resources have not only become an increasingly important area of military and economic competition in the world, but also will become a strategic space and base for human survival, development of society, and continued prosperity of the Bohai Sea. In view of this, the coastal countries, especially the powerful navies, are all building the seapower as the core, and they will vigorously develop naval equipment for the purpose of enhancing the ability to control the oceans, safeguarding the marine rights and interests, and the territorial integrity of the integrated sea system and the ability to exploit and utilize the marine space. Marine safety equipment and marine engineering equipment.
Marine engineering materials must have high strength, seawater-resistant hydrothermal corrosion, anti-sulfidation corrosion, anti-microbial adhesion, and high toughness. Titanium is light, high-strength, and corrosion-resistant. It is particularly immune to the erosion of salt water or seawater and the marine atmosphere. It is a high-quality, light-weight structural material called “marine metal” and is an important strategic metal material. Titanium has a wide range of uses in marine engineering and is particularly suitable for lightweight marine equipment. It is one of the key new materials in the ocean engineering field. Therefore, the full use of marine materials, titanium and titanium alloys, will contribute to the national marine strategy. development of.
Titanium alloys in marine applications
Application on ships
Titanium alloys used in the shipbuilding industry began in the 1960s, about 10 years later than titanium in the aviation industry. The United States, Russia, Japan, and China were the first countries to engage in the research and application of titanium in the field of ships.
Hull structural material
The hull made of titanium is lighter than previous fiber-reinforced plastics (9200, -25.00, -0.27%), aluminum alloys, steels and other materials, and can increase the effective loading weight, long service life, and almost no maintenance. It is easy to remove surface-attached marine life. Titanium fishing boats built by Japan Iron & Steel, Toho Technologies and Eto Shipbuilding have hulls, decks and structural parts made of titanium.
The 12-meter length of the Titan Express is a Japanese-made Nissan Industrial Co., Ltd. The shape of the hull is a beautiful three-dimensional curve that can minimize navigational resistance.
Ship pumps, valves, pipes and other accessories
The pumps, valves and pipelines on ships have only 2 to 5 years of service life due to the very poor working conditions. Titanium has excellent corrosion and erosion resistance, good yield strength and low density, so it can be used to make thin-walled, small-diameter pipelines, valves, and other accessories. Producing ships' pipelines and accessories from titanium not only reduces weight, but also significantly extends system life and reliability. For example, the density of the titanium condenser decreases by nearly 1/2 compared to the B30 condenser. The experience of warships using titanium alloy pipes and equipment shows that titanium alloy materials have high reliability both in terms of mechanical strength and resistance to seawater corrosion. The corrosion life of titanium alloy pipes, valves, pumps and other accessories is not less than 1.2h×105h, and the service period is not less than 40 years. The service life of various pumps, valves and tubes made of titanium alloys is far greater than that of copper or stainless steel products.
The use of titanium alloys to make propellers and shafts for ships can increase propulsion speeds and extend service life. The United States has used titanium propellers on various ships. For example, a 1500mm diameter, four-leaf detachable supercavity titanium alloy propeller is used on hydrofoil boats in the United States. Titanium is also an excellent material for water jet propulsion devices. Japan’s torpedo boat “PT-10” uses a Ti-6Al-4V alloy water jet propulsion device. Under the condition that the rotational speed is constant, the shaft diameter is reduced from 95mm to 75mm, and the weight is reduced by 600kg. The power plant of an atomic power icebreaker made in Russia also uses a titanium steam engine. The use of titanium alloys can extend the life of their engines by more than 10 times. In addition, a large amount of titanium alloy material is also used on ship engine parts such as engine disks and rotor blades. The use of a titanium alloy power propulsion device can also overcome the disadvantages of using copper alloys to cut the earth's magnetic force lines during navigation to generate large induced currents and to prevent the removal of magnetic mines.
In China in the 1960s, research on propellers was carried out. In 1972, hydrofoil speedboat propellers were developed. Various types of titanium alloy propellers with diameters ranging from 450mm to 1100mm have been produced so far, and the largest diameter is 1200mm and the mass is 130kg. Alloy propeller. The 25-type torpedo speedboat developed in China uses titanium alloy instead of the original AK-27 steel and copper alloy, which reduces the weight by 30% to 40%, increases the life expectancy by several times, eliminates the need for surface coating, makes marine life easy to clean, and maintains. Convenience.
Heat exchangers, condensers, coolers, evaporators
Heat exchangers, condensers, coolers, evaporator piping systems, valves, etc. can all be made of titanium. Equipment made of titanium can have a non-maintenance service life of more than 100,000 hours and will not release harmful substances. Friendly, while copper-based alloys release harmful copper ions to the environment due to corrosion. In October 2016, the national key R&D project “Development and Application of Low-cost, High-resistance Titanium and Titanium Alloy Tubing and High-Quality Titanium Strip Manufacturing Technology” was launched in Kunming. The project was co-owned by Yunnan Titanium Industry Co., Ltd. of Kunming Steel Holdings Co., Ltd. The company takes the lead. This project meets the country's strategic needs and uses offshore oil drilling platforms, seawater desalination, large-scale ship engineering and other major projects as its application background. It aims at the gap between the development and application of titanium and titanium alloy pipes in China and foreign countries and the urgent need for breakthroughs. The relevant manufacturing technology, through the research and development to achieve engineering applications.
In seawater, whether it is light waves or radio waves, the attenuation is much greater than the attenuation of sound waves. Therefore, in the business of exploiting and utilizing the sea, sonar is widely used in ships, torpedo searches, and detection of underwater targets. In sonar equipment, a variety of different performance acoustic materials are needed. Among them, the shell of the naval vessel, torpedo sonar and the shell of the high-pressure sound-transmitting vessel are made of water-acoustic sound-permeable structural material.
Generally, the purpose of installing a streamlined sonar shroud outside the marine sonar transducer is to reduce the hydrodynamic noise generated during the movement of the naval vessel and to ensure the effective and normal operation of the underwater acoustic device, thereby increasing the range of the sonar. The sonar shroud must have good acoustic performance so that there is only minimal loss and distortion of the underwater acoustic signal. According to the requirements of underwater and surface applications, there are basically two types of sound-transmitting materials for shellboards used by sailors in China. The first is stainless steel and the other is fiber-reinforced glass (1472). , 1.00, 0.07%) Steel. Russia also used glass steel in the past, but most of them later used titanium alloys. Titanium alloys have good acoustic performance. Many large-scale battleships abroad, such as Russian modern class, have their sonar flow hoods made of titanium alloys. They are used in Russia's Kursk, Titanium Minsk, and Kiev. No. 6 aircraft carrier sonar system.