ANALYSIS AND CONTROL OF NOZZLE CLOGGING OF 45 STEEL
In this paper,the problem of nozzle clogging during the production of 45 steel is studied and the improvement measures are put forward.The high-speed data acquisition system and EDX fluorescence analysis technology are used to monitor the fluctuation of molten steel and analyze the composition of nozzle clogs.The results show that the reason for nozzle clogging is the accumulation of high melting point Al2O3 non-metallic inclusions and CaS formed during calcium treatment on the inner wall of the nozzle.The fundamental solution is to reduce the amount of Al2O3 produced,while preventing the formation of CaS of excessive[Ca]and[S].The process is optimized with the calcium content in molten steel is controlled at 6 × 10-6～10 × 10-6,the binary alkalinity R of the LF process slag mixture ratio is in the range of 3.5 to 5,achieving a controllable sulfur content.At the same time,sulfur alloying is advanced before VD vacuum;The aluminum content of LF departure station shall be controlled within the range of ≤ 0.015％.After VD vacuum,reduce the types of alloying,and conduct calcium treatment after aluminum alloying.The interval time is set to 3～5 minutes.Control the superheat of molten steel at 25～35 ℃.After the optimization of the process,the castability of 45 steel is good,stable production of the entire casting process is achieved and the problem of nozzle clogging is also solved.
万方数据
维普
