Among the various large transformers, there is a special type of steel: oriented silicon steel. It is the “core” manufacturing material in transformers and is called “crafts in steel products”.
At the Silicon Steel Research Institute of Central Research Institute of SHBG Steel Co., Ltd., the reporter saw a sample of oriented silicon steel. The surface structure of the steel plate is like a map stitched together. Researchers told reporters that this irregular “map” is the grains of oriented silicon steel. After pickling, a diamond-shaped pit will be found under the microscope observation, and the direction is exactly the same as the rolling direction of the steel plate.
The former president of the Central Research Institute of SHBG Steel Group and the current technical adviser of BW Group Zhang Xunjun once made a vivid analogy: “It’s like a uniform team moving in one direction, almost all the grains stay in one direction, the smaller the deviation , The higher the electromagnetic and magnetic properties. “It is no exaggeration to say that oriented silicon steel is the most difficult variety to make in steel products, so it is also known as the” crown pearl “of steel products. The production of oriented silicon steel is an important indicator of the level of manufacturing technology of a country and a steel company.
Innovative approach, low-temperature manufacturing subverts traditional processes
Prior to 2008, only a few steel companies in the world were able to manufacture oriented silicon steel. China is the world’s largest importer of oriented silicon steel, especially high-grade oriented silicon steel used for high-performance transformers, almost all of which rely on imports.
As for the research on silicon steel products, SHBS Steel has gone through a lot of hard work. The traditional high-temperature manufacturing process requires a reheating temperature of nearly 1400 ° C. The slab melts, and “hanging slag” appears. Like ice hanging on the eaves in winter, production is very difficult. In tackling the difficulties, SHBS Steel’s engineering researched the traditional high-temperature process methods thoroughly. After hundreds of thousands of experiments and explorations, they independently developed a low-temperature manufacturing process and reduced the temperature of the traditional heating furnace by more than 200 ° C, which greatly enhanced This improves the manufacturability of oriented silicon steel.
One sword in ten years, a new peak in high magnetic orientation silicon steel
In the second half of 2008, low-temperature and high-magnetism oriented silicon steel and laser scored oriented silicon steel products were successively rolled off the production line at SHBS Steel, and mass production was achieved. In the following 8 years, Baosteel’s new high-end oriented silicon steel products were first applied to major national projects such as the “Three Gorges” and “Electric Power Transmission from the West to the East”, breaking the monopoly position of imported products in the field of ultra-high voltage, ultra-high voltage AC and DC transformers; fully replacing imports The product has broken through the predicament of being “stuck on the neck”. The import volume of high-end oriented silicon steel in China has dropped by more than 50%, and the average price has decreased by about 60%.
SHBS Steel’s “R & D and Industrialization of Low Temperature and High Magnetic Orientation Silicon Steel” project won the 2013 National Science and Technology Progress Award.
Ten years later, with the support of the key basic materials technology improvement and industrialization key projects of the “Thirteenth Five-Year Plan” national key R & D plan, after unremitting efforts, SHBS Steel’s oriented silicon steel finally reached a new peak. In 2019, SHBS Steel developed a new grade of oriented silicon steel with the world’s lowest loss of 0.18 mm specification 060 grade, which is 2 grades higher than the current highest international grade. In the past 10 years, Baosteel has launched eight new oriented silicon steel products in the world for the first time, and more than 30 new products have filled domestic blanks to achieve full coverage of the highest grades of oriented silicon steel of all thickness specifications. The new product is the first to be used in the manufacture of silicon steel laminated core distribution transformers that exceed the current national level 1 energy efficiency standard and UHV DC converter transformers with the highest voltage level in the world ± 1100kV.
According to reports, if 060-grade products are used to manufacture super-level 1 energy-efficient transformers to replace China’s high-energy-consumption transformers, annual energy savings will be about 90 billion kWh, which is close to the annual power generation of a Three Gorges power station.