This project belongs to the technical field of metallurgy and material preparation. Its main contents and characteristics include:
1)Electromagnetic purification technology of molten steel in tundish
The production of high-clean steel has always been a challenging problem facing my country's steel industry. This project innovatively proposes a new idea of using electromagnetic fields to optimize the overall molten steel flow field and inclusion movement trajectory in the tundish, extend the average residence time of molten steel in the tundish, and promote the floating of inclusions and improve inclusion removal efficiency. The technology of electromagnetic purification of molten steel in tundish has been developed and successfully implemented in industrial applications. The deoxidation capacity of the tundish has been increased by three times. The total oxygen content in the cast billet has been reduced by 10-25% compared with the traditional process, and the elongation rate of the cast billet has been increased by 10-20%., The tensile strength has been increased by 6-7%, the content of Class D fine system inclusions has been reduced by 47.9% compared with the traditional process, and the Class D coarse system inclusions have been reduced by 34% at most; The new technology can be fully matched with the existing continuous casting process and can achieve multiple continuous casting of refractory steel grades. This is also the first time at home and abroad that the idea of using electromagnetic fields to generally control the flow field structure of molten steel in the tundish and maximize the removal of non-metallic inclusions in molten steel has been proposed, and large-scale industrial tests have been carried out for the first time at home and abroad. In addition, this technology eliminates the mechanism proposed by Japanese scholars to use centrifugal force to separate inclusions, which has breakthrough guiding significance for improving the purity of stainless steel and high-alloy steel.
2)Electromagnetic field purification technology of non-ferrous alloy melt
Fine non-metallic inclusions in non-ferrous metals and alloys are often difficult to remove by conventional gravity means due to factors such as the small difference in density and melt. This project takes advantage of the huge difference in electrical conductivity between inclusions and metal melts, and uses electromagnetic buoyancy effect to efficiently remove inclusions. Successfully developed a variety of new electromagnetic purification technologies. Through research, the movement laws of inclusion particles in metal melt under electromagnetic fields were grasped, a theoretical model of inclusion removal efficiency was established, and the problem of turbulence deteriorating the electromagnetic separation effect was solved. A multi-layer parallel network channel structure was proposed to cleverly solve the problem of purification depth and melt handling capacity. The problem that cannot be balanced. In response to the alternating current purification scheme, a new idea of using induced flow to cooperate with electromagnetic separation of inclusions is innovatively proposed; the electromagnetic purification technology has been successfully applied to the melting and casting of pure aluminum, aluminum-tin alloys, copper and their alloys, and the inclusion removal efficiency has been significantly improved. The produced aluminum cast and rolled plate can be used as the base material of PS plate and double zero-grade aluminum foil; the elongation rate of the aluminum-tin alloy cast billet is doubled and the tensile strength is increased by 10-20%; Copper materials with high cleanliness, high density, and ultra-low oxygen content have been prepared. The performance far exceeds similar products of Japanese and Finnish companies. They have been used in microwave oven magnetron, Lanzhou particle accelerator, ITER project and other fields. Electromagnetic purification of aluminum melt technology and industrial testing of copper melt are also the earliest industrial practices at home and abroad.
(3) Electroinduced phase transfer technology under magnetic field
Electromigration purification technology requires high current density, high energy consumption, and low efficiency. This project team proposed a new idea of using static magnetic fields to enhance the electromigration process. The results show that when a magnetic field and current are applied in parallel to Al-Si, Bi-Mn and other alloy melts, the solidified primary phase particles will migrate towards the cathode; the increase of magnetic field intensity and current intensity will promote the increase of the migration speed of the phase particles. The critical current density required for directional migration of phase particles is 2-4 orders of magnitude smaller than that of traditional electromigration, and the critical magnetic field strength is only 0.1T. This is the first time that a new phenomenon of magnetically migrating phase particles has been discovered at home and abroad, and a new mechanism for micro-eddy current effect is proposed. This study provides a new idea for the refining of high-purity metals, especially rare earth metals. The research results were published in Acta Materia et al., and were reported at the annual conference at the special invitation of the Japan Iron and Steel Association.
At relevant appraisal and acceptance meetings, experts believed that this research had reached the "international advanced level." The industrial application of the above technologies has produced significant economic and social benefits. Published 68 papers (27 included in SCIE), authorized 20 patents, won 6 honors including the "National Outstanding Doctoral Thesis Award" and the Metallurgical Youth Science and Technology Award, and won more than 20 national, local and enterprise commissioned projects.