Study On Behaviors Of Ferrite Warm Deformation Of Ultra Low Carbon Steels

Ferrite deformation of steels at warm temperature is a new production technology, which is suitable to produce low carbon(LC) and ultra low carbon steels(ULC).The researchers in foreign countries began research on the low temperature processing in ferrite region of ULC many years ago and their researches involved many different fields, including influences of deformation technology schedule on product microstructure and properties, dynamic recrysterllization and static recrysterllization during deformation and deep drawing property of products, influences of microalloy elements on microstructure and properties of deformed metals etc. At the same time, this new technology of processing steels has been successfully used in the production of ultra thin strip and deep drawable steels. But the researches in this field in China began very late and research fields are very few. About 10 research papers published so far mainly dealt with the texture of products under the condition of ferrite deformation of ULC at warm temperature. In general, so far there have been few papers about basic deformation behaviors of ULC, such as flow stress model, dynamic recrysterllization and static recrysterllization during ferrite processing of ULC. Corresponding to this situation, this new metal processing technology has not been used in the production of steels in China.Changing the deformation temperature from the"hot"to"warm"or"low temperature"regime leads to a considerable change in the physical metallurgy. During, or before, ferrite deformation (warm deformation), the workpiece undergoes a transformation from the austenite phase to the ferrite phase. This change in structure has a significant impact on the product metallurgy both during and after forming. The transformation and recrysterllization of ferrite are therefore an integral part of the physical metallurgy of ferrite (warm) deforamtion.According to the research situation in foreign countries and in China,"The Researches on Deformation Behaviors of Ferrite Processing of Ultra Low Carbon Steels at Low Temperature"was selected as the research item on the basis of reading a lot of research literature. The influences of deformation technology parametres on flow stress , dynamic recrysterllization and static recrysterllization during ferrite deformation of ULC etc are included in the research in this dissertation. The purposes of research in the dissertation are to provide the theoretical basis for deciding the suitable...