Guide: Regrettably, although my country's shaft-making technology is close to the world's top level, the material—that is, high-end bearing steel—is almost entirely dependent on imports.

'High-end bearings rely on imports, why can't we make them ourselves?' After investigating five or six provinces including the three provinces of Northeast China, Zhejiang and Shandong, Wang Dongsheng, executive deputy director of the Shandong Technology Transformation Center of the Chinese Academy of Sciences, found the answer: the biggest question In terms of material, 'without good steel, high-end bearings can never be made'.

As an indispensable core component in mechanical equipment, bearings support the mechanical rotating body, reduce its friction coefficient, and ensure its rotation accuracy. In his view, whether airplanes, automobiles, high-speed rails, or high-precision machine tools, instruments and meters, 'all rotating parts need bearings.'

It is no exaggeration to say that the bearing in the engine has been working in 'purgatory'-it not only has to run at a high speed of tens of thousands of revolutions per minute for a long time, but also endure various forms of stress extrusion , Friction and ultra-high temperature. This puts forward high requirements on the accuracy, performance, life and reliability of the bearing, and the key factors that determine these four points are the material.

Unfortunately, although my country's shaft-making technology is close to the world's top level, the material-that is, high-end bearing steel almost all depends on imports.

Recently, a reporter from Science and Technology Daily visited a large state-owned steel group in East China and learned about the embarrassment of the latter. As the 'Top 100 Chinese Enterprises

'PPM' is a unit of oxygen content in steelmaking, which means parts per million or parts per million. An expert from the Institute of Metal Research of the Chinese Academy of Sciences told the reporter of Science and Technology Daily that, generally speaking, in the steel industry, 8 PPM steel is good steel; 5 PPM steel is top grade steel, which is exactly what high-end bearings need. The research and development, manufacturing and sales of high-end bearing steel are basically monopolized by the world's bearing giants Timken of the United States and SKF of Sweden. In the past few years, they established bases in Yantai and Jinan, Shandong, sourcing low-end materials from China, using their core technology to make high-end bearings, and selling them to the Chinese market at ten times the price.

Adding rare earths in the steelmaking process can make the original high-quality steel more 'strong'. But how to add, this is the core secret of the world's bearing giants.

Rare earths are called 'industrial vitaminsIn the 1980s, my country set off an upsurge in the development and application of rare earth steels. Scientists generally believe that adding rare earths in the steelmaking process is the technical direction to solve high-end bearing steels. However, after adding rare earths to the steel, the performance of the steel becomes There are good times and bad times, and it is easy to block the gate in the mass production process. Although the technical bottleneck has not been broken through many years of research, this has also caused the application of rare earths in the iron and steel industry to change from hot to cold.

Similar to a drop of ink in the same basin, how much rare earth is appropriate to add to 1 ton of steel? How to add it?

The problem remains unsolved, and the consequence is: At present, with the exception of a small number of steel grades, iron and steel companies have almost given up the application of rare earths in actual production.

However, the road to the development of high-end bearing steel is not all bad news.

In the previous stage, the material processing simulation research team of the Institute of Metals, Chinese Academy of Sciences conducted physical anatomy and calculations of single-weight 100-ton large steel ingots and found that impurities are the main source of uneven composition. Based on this, a new defect in steel was proposed. The formation mechanism has caused great repercussions in the industry and has been quickly applied. Since then, the team has developed the purification preparation technology of commercial rare earth alloys and the special addition technology of rare earths in steel, thus breaking through the technical bottleneck of the industrial application of rare earths in steel, and realizing the smooth and smooth process of adding rare earths to steel. Stable performance.

The reporter learned that recently, relevant national ministries and commissions are preparing relevant policies to promote the localization of high-end bearing steel. It can be said that we have taken another step forward to solve the problem of 'stuck neck' of high-end bearing steel.

Source: Science and Technology Daily