Research On Cord Steel Refining And The Other Issues

Cord steel is the raw materials of tyre meridian. Cord steel is a kind of hightechnical content of clean steel. Key problem in cord steel production is to control thegeneration of large particles non-deformation non-metallic inclusions.This large sizenon-deformation non-metallic inclusions will cause the broken wire phenomena in theprocess of wire drawing. Therefore, cord steel production has a very strictrequirements for controling non-metallic inclusion.In order to reduce the precipitation of non-deformation inclusions which hasmuch Al2O3in liquid steel, the production of cord steel uses acidic slag in the processof refining to curb aluminum of liquid steel rising back in refining process. In thispaper, we regard a steel smelting LX70A as the research object.We make athermodynamics analysis about the influence which is FeO in slag to resulfurizationof liquid steel in the process of acidic slag refining. Then according to the result ofthermodynamic calculation, the activity of refining slag system model isestablished.Thus we analyze a series of factors of influencing FeO activity inslag,and arrive at the effective measures to control sulfur content in liquid steel. Inorder to effectively control the precipitation of inclusions which is main consist ofAl2O3in liquid steel, we make a thermodynamics analysis about the influence of theAl2O3content in refining slag to the aluminum content in liquid steel,andestablish the relationship of activity of Al2O3in slag and the aluminum content inliquid steel Al2O3activity of slag. Thus further activity model is set up. The effects ofvarious factors on Al2O3activity of slag system are studied.Then we arrive at theeffective measures to control the composition of the slag. The above research worklaid the foundation for proving the effective measures to control sulfur content andaluminum content of liquid steel with acid slag in smelting process.