High-end hydropower steel & ultra-high performance structural steel

Compared with the experience of the Three Gorges Project, the total demand for special steel for the Yajiang Hydropower Project is expected to reach 4 million to 6 million tons."The required steel grades mainly include the following types:

High-end steel for hydropower: Used in 100-megawatt large-scale hydroelectric generating units, such as large-scale magnetic yoke steel plates, magnetic pole steel plates, steel plates (ultra-thick plates) and steel for high-pressure branch pipes， which are highly resistant to extreme complex stress conditions. These types of steel require extremely high standards in terms of purity， homogeneity and performance stability.

Ultra-high performance structural steel: It is used for constructing ultra-high dams, super-large span underground cavern support structures, giant pressure pipes and gates, etc. It must possess an ultra-high strength of over 800 megapascals, an extremely low brittle transition temperature, excellent resistance to laminar tearing, outstanding weldability, and significant corrosion resistance requirements for stainless steel are also required.

Corrosion-resistant special steel: For water transmission systems, flood discharge facilities, underwater structures, etc., which are in contact with corrosive water environments for a long time, high-grade stainless steel is required, such as duplex steel, special alloy composite plates, high-performance coated anti-corrosion steel, etc., especially in areas with high-flow and sandy water currents.

Special steel for super-large engineering equipment: The cutter disc of the shield machine requires extremely strong wear-resistant alloy steel, the key load-bearing components of giant cranes need ultra-high strength special steel, and the core components of super-large construction machinery also have a large demand for high-end special steel.

High-end electrical steel: The stator of a hydroelectric generator requires 0.35-0.5mm thick electrical steel with high magnetic permeability and low iron loss, which is un-oriented and suitable for power transmission, such as grades 50W350 and above. This is to enhance energy efficiency. Power stations equipped with ultra-high voltage transformers also need high-performance oriented electrical steel.

"The high-altitude and low-temperature environment may increase the brittleness of steel, and the service life of the project is as long as decades, requiring a new balance between material life and maintenance costs. The experience of using steel in traditional hydropower stations can no longer be fully replicated. We must innovate our thinking, carry out collaborative research, and adopt customized R&D paths."

On July 23, the China Special Steel Enterprise Association (hereinafter referred to as the Special Steel Association) held a seminar on special steel for the Yajiang Project in Beijing. The experts at the meeting conducted analysis and research on the quantity, variety, quality, standards and supply channels of special steel for the Yarlung Zangbo River Hydropower Project, and discussed the opportunities and challenges of special steel development in the super hydropower project industry chain.

The experts at the meeting unanimously agreed that the Yajiang Project is a national super project, which is a major opportunity for the development of special steel, and it is necessary to attach importance to the development of new high-quality special steel products. The delegates at the meeting proposed that they look forward to organizing the establishment of the "Yajiang Engineering Special Steel Expert Group" to build an industry-university-research platform and establish a long-term and stable supply-demand docking mechanism; it is recommended that the Special Steel Association take the lead in organizing the industry's R&D and production advantage units to connect with relevant units of the Yajiang Group, and gather the strength of the Association's Expert Committee, the Special Steel Association's Standardization Committee, leading enterprises, scientific research institutes and universities to provide special steel high-end material support and guarantee for national super projects.

The meeting was chaired by Liu Jianjun, Secretary-General of the Special Steel Association. Zhao Fazhong, Deputy Secretary-General of the Special Steel Association, Yu Kou, Senior Consultant, Dong Han, Head of the Special Steel Association's Specialized Expert Group and Dean of the School of Materials of Shanghai University, Jiang Zhouhua, Vice Chairman of the Special Steel Association's Expert Committee and Professor of Northeastern University, Xu Xiaochun, Executive Deputy General Manager of Nangang Group, Sun Jiuhong, Chief Engineer of Northeastern Special Steel Group, Li Tao, Chief Engineer of Fushun Special Steel, Ma Dangcan, Professor of the Steel Research Institute, as well as representatives from special steel enterprises and scientific research institutions such as CITIC Special Steel, Baowu Special Metallurgy, Daye Special Steel, and Xining Special Steel, members of the Special Steel Association's Expert Committee, and members of the "Specialized Specialized" Expert Group attended the meeting.

Liu Jianjun said that as a major national strategic project, the Yajiang Project has a construction scale far exceeding that of the Three Gorges Project, and is located in a high-cold, high-altitude, and highly corrosive environment, which puts forward higher standards for the strength, corrosion resistance, and durability of special steel materials. The steel consumption of this project is expected to reach millions of tons, with a long demonstration cycle and high technical requirements. The special steel industry needs to act quickly, gather wisdom and strength, provide special steel solutions, and respond to national needs with a high sense of responsibility and mission.