The Study On Quality Control Of 45 Steel In Converter

In our country steel products employed period long, timbering more and the supply of scraps little limited the development of electric cooker. So many converter plants exploited special steels with high additional values as a new way to attain economic benefit. At present, use blast furnace-converter-continue casting producing carbon structural steels is one of the most future processes in special steel manufacture technique.Shi Jiazhuang iron and steel Corp. has discussed the"blast furnace-converter-continue casting"technics produce 45 steel for cost and attained better economic benefit after the process was put into use. But because of the questions of the components difficult to control (mostly C component), liquid steel's clogging and the quality of slab difficult to ensure the slab's capabilities are not stabilization.This paper abstractly analyzed the feasibility and future of the process of top blown oxygen converter-secondary refining-continue casting producing 45 steel. Through large numbers of production data, analyzed the some importance technical parameters of the process of converter producing 45 steel in Shi Steel and put forward the academic gist for ascertain the practical operational technical parameters. Analyzed the evolvement rule of total oxygen content and solved oxygen and the amount change of large inclusions and micro-inclusions in working procedure of smelting 45 steel, supplied bases for the improvement of technics and steel cleanliness and the exploitation of else special steels. Applied PHOENICS to simulate the flow field of ladle. Using equations of homogeneous model and the equations of Navier-Stokes andκ-εestablished fluxion model, accounting numerical value got the more rational flow field to insure the uniformity of liquid steel and temperature and urge inclusions removal, provide eligible liquid steel for continue casting.Top blown oxygen converter adopted recarburization to smelt 45 steel and resolved the end carbon different to control. In order to remove inclusions, rapidly increase the temperature and uniform the component of liquid steel, simulated the flow field of liquid steel in LF, got the better position of argon bottom blow stirring ladle 0.4r～0.45r to improve the effect of deoxygenization and reduce the probability of nozzle clogging. Using the result of the simulation total oxygen content of the slab reduced from 0.0069% to 0.0046%, reduced 33%.At present, Shi Steel have tow converters to alternate smelt 45 steel, the rate of steel grades ensuring exceeded 99%; after refining ,liquid steel was sent to continue casting via tundish, the rate of slab yield reach to 99%.