Study On The Slab Internal Quality And Inclusions Of Q195

With the successful development of Q195steel, the technology system of TangshanGuofeng Iron and Steel CO.,LTD is still in the exploration and perfection. Qualityproblems of products in production process happen from time to time; the majorproblems are Steel surface quality, internal quality and inclusion control.To solve the above problems, some study means including systematical samplingand laboratory analysis are introduced to research on the origin surface quality, internalqualityï¼›Experiment with The waste slag of LF as the converter steel slag washingmaterial is introduced to research on the origin, type, size in Q195steel of Guofeng.The results of the study show that casting internal quality improved after tundishwas transformed. Secondary Cooling System third part working on casting solidificationend. Through the optimization of secondary cooling system, billet has been improvedobviously. LF refining slag can be used as slag washing material at converter, in thetapping process refining slag can melting quickly and fully, ladle slag average R morethan2.5, ladle slag oxidizing reduced5.64%, ladle slag modification effect is obvious.The content of rephosphori-zation; The content of resulfurization is not very apparent. Intop ladle the average of microscopic inclusions reduce7.45/mm²; in tundish the averageof microscopic inclusions reduce4.06/mm²; in casting the average of microscopicinclusions reduce5.21/mm². When the quantity of Refining slag added to3kg/t, thecontents of T[O] reduced6.32ppm, loss temperature7.12℃. After tundish istransformed the contents of T[O] reduce44.14ppm, the contents of N increased5.42ppm;the content of composite inclusions SiO₂-Al₂O₃-MgO-CaO reduced42.9%, SiO₂-CaO-MgO reduced13.1%, macro inclusions reduced21.9%, micro inclusions reduced52.66%.