Aluminum Alloy on Railway Vehicles

Railway transportation is an important

transportation in China, which plays an extremely important role in the development of socialist economy. Railway vehicles are the means of transportation carrying passengers and goods in railway transportation. As a main link in the railway, with the rapid development of railway, railway vehicles continue to improve towards lightweight, and the application of aluminum alloy materials is an important measure to promote its lightweight. This paper discusses the application of aluminum alloy on Railway vehicles.

1 Characteristics of aluminum alloy

Aluminum is a light metal with low density, about 1/3 of that of steel. Adding one or several elements to aluminum constitutes aluminum alloy. Compared with aluminum, aluminum alloy has more strength and hardness, better physical and mechanical properties, good durability, easy processing and wide application range. Compared with low-carbon steel, its strength can be better than some alloy steels. According to the added alloy elements, aluminum alloys can be divided into aluminum manganese alloy, aluminum copper magnesium alloy, aluminum copper alloy, etc. different kinds of aluminum alloys have different characteristics and application scope. Now we analyze their main characteristics in detail.

1) Light weight. The density of aluminum is 1/3 of that of steel. The car body made of aluminum alloy is 30% lighter than that made of steel, realizing the demand of lightweight.

2) Excellent mechanical properties. Nowadays, most of the aluminum alloys used in various industrial structural parts are 6061-T6, which belongs to the "Ai mg Si" series. Its mechanical properties are stable and excellent, which is convenient for engineering use.

3) Good corrosion resistance. When aluminum alloy is exposed to air, a fine oxide film can be formed on the surface, which can effectively prevent corrosion. Therefore, compared with other materials, it has better corrosion resistance, long service life and low operation and maintenance cost. Experiments show that among the commonly used aluminum alloy materials, AI mg 5083 has good corrosion resistance, followed by AI mg Si.

Extrusion properties. AI mg SI system materials have good extrusion properties, while AI mg system and AI mg SI system have poor extrusion properties. 6005b and 6005c have improved the stress corrosion crack resistance in the wall thickness direction of 7N01 alloy, which will be used more and more widely.

2.Application advantages of aluminum alloy on railway vehicles

1) Energy saving and consumption reduction, conducive to environmental protection. On the basis of lightweight, aluminum alloy can also meet the requirements of safety in strength. For high-speed trains, the best way to lighten the vehicle is to increase the proportion of aluminum used in the vehicle body.

2) Convenient for processing and manufacturing. With the continuous progress of aluminum alloy production process and aluminum alloy vehicle manufacturing technology, the manufacturing process of aluminum alloy car body is greatly simplified, and the manufacturing workload is relatively reduced. It does not need rust removal, can be recycled, easy to maintain, and is more conducive to processing and manufacturing. It is also suitable for various surface treatments. It can color and spray on the surface of aluminum alloy to improve its corrosion resistance and make the surface of car body more beautiful.

3) The price is moderate. The price of aluminum materials is high, and the vehicle manufacturing cost of aluminum alloy materials has increased. However, due to the characteristics of lightweight, aluminum alloy has brought the increase of transport capacity, the reduction of energy consumption and the reduction of maintenance cost to railway vehicles. Moreover, aluminum alloy vehicles have more recycling value. Among the recycling value of scrapped vehicles, steel vehicles are 100%, while aluminum vehicles are 480%. Therefore, aluminum alloy vehicles have high comprehensive benefits, moderate price and reasonable cost.

Good safety performance. The aluminum alloy car body is of profile structure, and its stiffness is much better than that of ordinary carbon steel car, so it can withstand greater mechanical external force and avoid fatal injury to passengers in the car. Moreover, aluminum alloy material also has excellent fire resistance and arc resistance. Compared with steel, it has better thermal conductivity and heat dissipation. These characteristics make aluminum alloy car body have better safety performance.

3 Application status of aluminum alloy on railway vehicles

High speed, energy saving, comfort, safety and environmental protection are the main objectives of today's transportation development. As the preferred material for lightweight development, aluminum alloy has many incomparable advantages, so it is more and more widely used in railway vehicles. In recent years, high-speed rail, high-speed magnetic pad and new hybrid structure vehicles with a speed of more than 300 km / h have been put into use, which has promoted the better development prospect of aluminum alloy. Nowadays, worldwide, the production and manufacture of aluminum alloy car body has become the overall trend of the development of urban rail transit and railway transportation. The passenger capacity and logistics volume of railway transportation in China are the first in the world. However, the development of aluminum alloy car body in China started late. Changchun Railway Passenger Car Co., Ltd. developed the first aluminum alloy subway car body in 1989, built China's first aluminum alloy automatic welding production line in 2001, and developed China's first maglev train,

Subsequently, Nanjing Puzhen vehicle factory, Tangshan vehicle factory and Zhuzhou Electric Vehicle factory have successively established production lines to gradually produce aluminum alloy car bodies. With the continuous development of China's transportation industry, the birth of "harmony" and the continuous development of urban subway rail transit, aluminum alloy car bodies appear more and more in people's lives. The Ministry of Railways has introduced foreign advanced production technology to realize the leapfrog development of railway. For example, the operation of Beijing Guangzhou high-speed railway and Beijing Shanghai high-speed railway has established a huge market demand for aluminum alloy vehicles, It has further promoted the development of aluminum alloy car body manufacturing technology in China. At the same time, because the manufacturing of aluminum alloy car body is still in the stage of rapid development and there is not a fully mature technology application system, there are also some technical problems

Question. Nowadays, the development of aluminum rail vehicles lags far behind the automobile transportation industry. Due to the long innovation cycle of aluminum products and the long service life of railway cars, the verification cycle of car body and car parts is long. On the whole, the use of aluminum alloy car body in the transportation market is far less than that in aerospace, automobile transportation and some civil markets. At the same time, the heavy load and high speed of railway transportation also put forward higher requirements for the wear resistance and corrosion resistance of railway engineering components. Nowadays, the use of high-speed train brake discs and arc spraying to repair railway bridges can obtain certain wear resistance, anti-skid and anti-corrosion

Erosion effect. In addition, there are many technical problems in the application of aluminum alloy in railway vehicles. For example, most of the parts of railway vehicle body are formed by stamping, and cracks are easy to appear when stamping aluminum plate by stamping steel plate; Most of the body workpieces are assembled by welding, but the welding of aluminum is more difficult than that of steel. The welded surface needs to be smooth, and the parts need to be electrophoretic and sprayed.

4 Application development of aluminum alloy on railway vehicles

Nowadays, countries around the world have organized a large number of human, financial and physical research on aluminum materials for vehicles and some new technologies and processes, especially in rolling process, extrusion process, material integration, large-scale and hollow, as well as various special properties, treatment methods, combination methods, material mixing methods, surface treatment, etc, Promote the development of railway aluminum materials towards high standards, high performance, energy conservation and environmental protection to a new level.

At present, with the continuous development of railway transportation and the deepening of the operation test of aluminum alloy vehicles, we need to carry out more extensive experimental research, appropriately introduce some advanced technologies and related equipment, and transform them into our own experience and technical use. At the same time, it is necessary to strengthen the technical research and development of aluminum alloy materials to effectively improve the comprehensive performance of aluminum alloy materials, such as integrating some new process methods, adopting spray forming and other processes, reducing manufacturing costs and stabilizing product quality. In addition, it is necessary to strengthen the research on welding process and control technology to improve welding quality, only materials and manufacturing

With the continuous development of manufacturing technology, we can explore a more reasonable vehicle structure. At present, China still depends on imports in some main manufacturing technologies, so we need to increase the research on technology and shorten the gap. In terms of the maintenance of aluminum alloy vehicles, it is necessary to improve the awareness of maintenance and environmental protection from the aspects of manufacturers, users and train inspection, formulate strict processes, improve the application management of vehicles, and effectively reduce the damage to aluminum alloy vehicles.

5 Conclusion

The application of aluminum alloy car body is the inevitable trend of railway transportation and urban rail development. Aluminum alloy has promoted the design and manufacturing technology of railway vehicles to a new level because of its good performance and many advantages. With the continuous development of aluminum alloy manufacturing and application technology, it will become the mainstream of the development and application of modern railway. We must constantly carry out technical research and development to promote the rapid development of China's rail transportation industry.