Can the mainland high-speed rail industry conquer the international market, but can not conquer a small bearing? In the domestic production rate of high-speed rail has reached more than 90%, high-speed rail bearings still need to be imported, so that the "light of domestic production" has cast a controversy and shadow?
What is the purpose of bearings? Why has China's high-speed rail been stuck by it?
Bearing, the soul of high-speed rail
Some people call it the soul of high-speed rail?
High-speed rail runs at high speeds, has large loads, large temperature changes, and complex environments, while bearings are mechanical components whose main role is to support rotating parts and reduce frictional resistance. In high-speed rail, they not only have to bear the huge loads of high-speed rail operation, but also adapt to the challenges of high-speed operation.
For example, the weight of a high-speed rail car is equivalent to the total weight of more than 20 ordinary cars, and the bearings need to withstand such weight pressure, as well as the huge centrifugal force generated by high-speed operation. According to statistics, the speed of high-speed rail trains can reach 350 kilometers per hour when running, and the centrifugal force experienced by the bearings in high-speed operation is equivalent to the gravitational acceleration when taking an airplane.
This centrifugal force will exert tremendous pressure on the bearing, and if the bearing quality is not up to standard, it is likely to break or be damaged, resulting in a safety hazard for high-speed rail.
The difference between easy and usable bearings directly affects the safe and stable operation of high-speed rail.
However, it is surprising that China, the world's largest steel country, still can't make high-end bearings. It is understood that at present, only the speed of the mainland is less than 140 km / h of high-speed rail bearings can be localized, once the speed exceeds this limit, the mainland still relies on imported bearings.
Is China's bearing really stretched? Not necessarily, the number of bearing steel in the mainland is the first in the world.
Bearing steel, as the name suggests, is a type of high-strength steel designed specifically for making bearings. It has excellent mechanical properties and wear resistance, and is able to withstand extremely high loads and rotational speeds. Bearing steel, the core raw material for the manufacture of bearings, is the main sales product of CITIC Special Steel Industry in the mainland.
It is probably that foreign companies buy our bearing steel, and then make it into bearings and sell it to China at a high price, just like China's Xinjiang cotton is sold to foreign countries, and foreign companies process it into down jackets and sell it to China at a high price. As a result, the price of bearing steel is 10 times higher than before.
High-speed rail bearings need to be stable under high temperature friction and low temperature conditions, without loosening, slipping or deformation. This has extremely high requirements for bearing steel, and we have to admit that the current bearing steel of the mainland can not fully meet this demand.
The patent is pinched by foreign countries, can domestic bearings still turn over?
The price of imported bearings is pinched by foreign-funded enterprises, even higher than 10 times its production cost, how do we turn over? In fact, we should indeed pay attention to the price of imported high-speed rail bearings, but not only focus on the price.
It is necessary to realize the coordinated development between products and industrial chains as soon as possible. Although the bearings of the mainland have long been exploited by foreign monopolies, we can think about it from a different angle.
The manufacture of high-speed rail bearings is inseparable from the "king of steel" - bearing steel. The mainland has become a major producer of bearing steel, but compared with the ultra-high purity bearing steel made by vacuum degassing smelting technology, there is still a certain gap in the quality and purity of domestic bearing steel.
In order to meet the needs of high-speed rail in various extreme conditions, we need to work on high-performance materials. By further improving the purity and quality of bearing steel, the wear resistance, corrosion resistance and load-bearing capacity of the bearing can be enhanced, so as to ensure the safety and reliability of high-speed rail.
In addition to high-performance materials, high-quality processing is also the key to realizing the localization of high-speed rail bearings. The improvement of precision machining technology can ensure the accuracy and reliability of bearings, and then improve the safety and stability of high-speed rail operation. For example, through precise grinding and heat treatment processes, the surface of the bearing can be smoothed and leveled, and its wear and corrosion resistance can be enhanced.
In order to ensure the localization of high-speed rail bearings, the government should increase support for the high-speed rail bearing industry. Provide a good policy environment and economic security, and create better development conditions for enterprises.
At the same time, enterprises also need to strengthen cooperation with foreign enterprises, learn from Xi their advanced experience and technology, and improve their competitiveness.
As well as improve the attention and treatment of relevant technical talents.
Although there is a lot of room for improvement in the field of domestic bearings, as long as we can make breakthroughs in high-performance materials and high-quality processing, the realization of domestic high-speed rail bearings is close at hand.
As of 2020, the total length of China's high-speed rail has exceeded 37,000 kilometers, more than twice the total mileage of high-speed rail in other countries in the world. The speed of operation has also reached the world's leading level. At 350 kilometers per hour, for example, China's high-speed rail has surpassed the high-speed rail systems of many countries.
However, in such a world-renowned high-speed rail system, bearing parts are still a technical bottleneck.
We should not only be satisfied with the growth of the number and speed of high-speed rail, but also pay attention to technological innovation and independent research and development. Only by strengthening the research and breakthrough of core technologies can we truly realize the full autonomy of the high-speed rail industry.
How about our technology?
I have to say that we do have a gap with foreign technology, and even China is still caught in the whirlpool of fake bearings. In fact, it is easy to understand when you think about it, if we have enough technology, do we still use fraud?
However, since 2006, the scale of China's bearing market has gradually expanded. In 2020, Luoyang LYC Bearing Company made an important breakthrough at the high-speed rail bearing independent research meeting held in Luoyang, Henan Province. According to media reports, the company has successfully developed high-speed rail bearings that can be applied to speeds of 250 kilometers per hour and 350 kilometers per hour, and has undergone durability tests of up to 1.2 million kilometers.
Although the demand for high-speed rail bearings in the domestic market is not very large, and the overall sales volume is relatively low, this breakthrough is of great significance. This means that the localization rate will be improved, and China's high-speed rail will be able to slowly get rid of its dependence on European and Japanese bearings in the future. This is a major milestone for China's high-speed rail industry.
The size of China's bearing market reached 227.8 billion yuan in 2021, an increase of 8% year-on-year. According to the data of the China Bearing Industry Association, the mainland has become the world's third largest bearing producer in terms of market size and sales revenue.
Moreover, in October this year, Chinese enterprises successfully developed the main bearing of the shield machine with a diameter of 8.61 meters, creating a record of the world's largest diameter, the heaviest monomer and the highest bearing capacity.
This breakthrough achievement marks that Continental has made significant progress in the development of domestic super-large diameter main bearings, and has achieved full coverage of the main bearings of shield machines from small and medium-diameter to super-large diameters.
This set of main bearings is independently developed by China Railway Construction Heavy Industry Group, which is suitable for driving 18-meter ultra-large diameter shield machines. The weight of the product reaches 62 tons, which can withstand loads in the order of more than 10,000 tons. In the raceway plane with a diameter of more than 8 meters, its flatness is less than 20 microns, and the manufacturing difficulty is no less than carving on rice grains. Prior to this, the key technology of the main bearing of the super-large diameter shield machine has been monopolized by foreign companies for a long time.
High-speed rail has become China's new business card, not only a means of transportation, but also a symbol of China's advanced technology and development strength. As the new business card of the country, it is the responsibility of each of us to polish this business card brighter.
Resources:
"Academician Zhongyuan Walks into Luoyang to Discuss the Autonomous Development Direction of High-speed Railway Bearings", Henan Daily.2020.10.15
"Analysis of the Gap between Domestic and Imported Bearing Technology and Application", Asia International Power Transmission and Control Technology Exhibition.2020.03.18
"Breakthrough in the Development of Main Bearings of Domestic Super-large Diameter Shield Machines", People's Daily Online.2023.10.13
"Focus Interview: China's High-speed Rail to the World", CCTV.2023.05.18
"Analysis of China's Bearing Steel Industry in 2022, Improving the Level of Product R&D and Manufacturing is the Main Development Trend of the Industry" Huajing Information Network.2023.05.04