Evolution Of Microstructure During Hot Rolling And Normalizing Of RE And Nb Microalloying Fe-3%Si Non-oriented Silicon Steel

As the pillar industry of national economy, iron and steel industry is the importantsupport and guarantee to the national construction and economic development. So far theelectrical steel has had a long history which is over one hundred years. This kind of steel,as an important soft magnetic materials, is widely used in electricity, electronics andmilitary industries in making motor, transformer core and manufacturing electricalcomponents. The electromagnetic properties of electrical steel plate mainly depends on thepurity of steel chemical composition, inclusion aggregation degree, the strength of therecrystallization organization as well as the texture component. The study shows that therare-earth can play a vital role in microalloying and improve the performance of steelproducts. Since our country has the advantageous superiority in the rare-earth resourcesreserve, The rare-earth industry of REO ore reserves in Bayan Obo, Inner Mongolia canreach43million tons, accounting for36%of the world. However, rarely research reportsof the application of rare-earth in high grades non-oriented silicon steel have been reported,so the research on recrystallization behaviors during hot-rolling of rare-earth microalloyinghigh grades non-oriented silicon steel has a great significance.The paper “Evolution of microstructure during hot-rolling and normalizing of RE andNb microalloying Fe-3%Si non-oriented silicon steel” is based on the help ofGleeble-1500D, OM, SEM, EBSD and other modern testing and analysis technology,conducts the single, double, multi-channel pass thermal simulation compressionexperiment and hot-rolling, coiling, normalizing to study the static and dynamicrecrystallization behaviors.The results show that: the experimental steels in single, double, multi-channel passthermal simulation compression experiment belong to ferrite area. Although there is a partof recrystallization grain which appears in original grain boundary or the triangle area ofgrain boundary, the stress-strain curve under different deformation temperature,deformation rate is still the model of dynamic recovery. The temperature and rate of deformation have an influence on the resistance of deformation, but the sample will notoccur static and dynamic recrystallization in the process of compression. The value Qdofexperimental steels are440.74KJ/mol and437.08KJ/mol, significantly improved the Qdby Rare-earth and Nb microalloying, meanwhile inhibit the occurrence of dynamicrecrystallization. The normalizing temperature of800℃after hot-rolling cannot occur therecrystallization in deformation grains, the normalizing temperature of1000℃afterhot-rolling often cause abnormal grew up in deformation grains, and the normalizingtemperature of900℃after hot-rolling can occur the recrystallization in deformation grains,so choose the appropriate temperature and time of normalizing for stable state ofhot-rolling microstructure, it is very important to improve formability of hot-rollingproducts, and can provide better product conditions for the cold-rolling process.