At present, China's UHV transmission and new energy grid connected anode saturation reactor, medium frequency transformer and other electrical equipment core materials ultra-thin orientation electrical steel has long relied on imports from Japan, the price is as high as 150,000-300,000 yuan/ton, while limiting its application in the domestic military, national defense, transportation and other fields, the annual demand exceeds 3,000 tons, high-end products urgently need to achieve localization.

To this end, with the support of the "13th Five-Year Plan" national key research and development Plan and the major project of the State Grid Corporation, the project team has broken through the basic theory and core technology of medium frequency ultra-thin oriented electrical steel from the base metal to the finished product, and achieved independent research and development and engineering application of high-end materials. The project team has concentrated the top research and production institutions in the field of research and development and application of oriented electrical steel, and has carried out systematic research work in the basic theory of oriented electrical steel, base metal and ultra-thin oriented electrical steel research and development, application technology, etc., and has reached the international leading level in the field of research and development, production and application of 0.18mm~0.35mm oriented electrical steel for power transformers. And a series of laboratory and industrial trial production research of ≤0.10mm ultra-thin oriented electrical steel has been carried out, which has the theoretical and practical basis to achieve the breakthrough of domestic high-end ultra-thin oriented electrical steel from "0" to "1".

As shown in Figure 1, this project adopts the technical route of consistent R&D and production from special base metal to ultra-thin oriented electrical steel. Research is carried out around the development of high-performance base metal - preparation of ultra-thin oriented electrical steel - integration of industrial production line in the whole process - establishment of multi-working condition application evaluation system - development and engineering application of iron core and equipment. Break through the basic theories such as the microstructure evolution mechanism of special base metal and ultra-thin oriented electrical steel, the grain competition and growth mechanism of Goss, the edge sharpening control of easily magnetized texture, and the matching mechanism of magnetic properties and microstructure morphology, develop the full-process industrial production process of high-performance base metal and ultra-thin oriented electrical steel, and create the multi-condition coupling test platform and evaluation method of material and core. To overcome the key technologies of core and equipment design and manufacturing, solve the problems of the lack of special base material, the basic theory of magnetic properties and organization control and the weakness of key technologies, and finally realize the mass production and engineering application of domestic materials, iron cores and equipment, and solve the problem of "jam neck" of core materials.

During the "14th Five-Year Plan" period, China plans to build 14 UHV DC power transmission projects, and the ultra-thin oriented electrical steel materials and anode saturation reactors developed in this project will continue to be applied to the subsequent DC project construction. A single ±800kV UHVDC transmission project uses about 3840 iron cores and 384 anode saturation reactors. At the same time, with the steady progress of the national "Belt and Road" strategy, the ultra-thin oriented electrical steel materials and devices developed by the project, the evaluation technology developed, the standards formulated and the promotion and application experience can be applied in the DC projects won by Germany, Brazil, Pakistan, Turkey and other countries to ensure the quality and safety of the project and enhance international competitiveness. At the same time, the products can be widely used in new energy grid-connected equipment with intermediate frequency transformers, rail transit intermediate frequency transformers, aerospace, military and other fields of high-end equipment, is expected in the next five years the total demand of more than 100,000 units.