Steel Mixed With The Source And Nature Of The Objects

The inclusions have reduced the plasticity, toughness and fatigue life of the steel, make cold-forming and hot-forming characteristics and even some physical performance of the steel bad. It influence to the intensity, extension, toughness, cutability, corrosion-resisting, surface finish, weld performance of various fields of steel. The concrete intensity that the performance of the inclusion to steel influences are decided by a series of factors, such as quantity, particle magnitude, shape and distribution and so on.The EAF-LF/VD-HCC process system in Hengyang Pipe Factory is a pipe production line that has the special characteristics. It places strict requirement on the molten steel quality. This process affects the formation of the micro-inclusions in the molten and the size, mechanical behavior, and the dispersion of the inclusions closely affect the product quality.In this thesis, a systematic study is conducted on the process inclusions course source, formation mechanism of inclusion, develop law and so on in order to guide the production, some control measure of optimizing the course inclusion are put forward to obtain high-quality tube bloom.The main contents:(1) The research of the inclusions source and forming mechanism in the steel;(2) The composition and size analysis of inclusions in the steel;(3) The research of inclusions development from EAF to tundish and the distribute low of inclusions in tube bloom.(4) The research of deformation and distribution of inclusions in rolling course.(5) The effect of process inclusions to tube bloom and steel pipe on quality and performance and the control method of inclusions are studied. The conclusion:1,The steel is produced easily some surface default in rolling course because rolling slag in the casting and the reoxidation of melt steel is serious, the quantity of big inclusion is high.2. The micro-inclusions source in tube bloom is oxidation than refraction than rolling slag in the ladle than tundish flux.3,The big inclusions source in tube bloom is tundish flux than rolling slag in the ladle than oxidation than tundish lining.4,The inclusion in steel is not obversouly influences for physical performance of tube although the quantity of micro-inclusions and big inclusions is high in the test.5,The classic surface default in the tube is because of the all kinds of inclusion in tube bloom.