高拉速条件下中碳钢连铸用保护渣的性能研究

Study on the properties of mold fluxes for the high speed casting of medium carbon steel

高拉速连铸技术因其高效生产的优点而备受人们关注,其中典型的紧凑型带钢连铸技术的连铸速度普遍提高至3~6 m/min,甚至达9 m/min。因高拉速连铸技术的拉坯速度提高,导致结晶器内部许多参数发生了改变,使得该工艺对保护渣的要求也变得颇为严苛。针对紧凑型带钢连铸连轧生产中碳钢所用保护渣开展了研究,并与传统低拉速连铸保护渣的理化性能进行对比。研究结果表明:中碳钢高拉速连铸用保护渣相比低拉速连铸用保护渣需要有更好的润滑性能,1300℃时的黏度应低于0.086 Pa·s(拉速3.5 m/min);因高速拉坯,结晶器内壁与初始钢坯之间的热流大大增加,为避免过快的传热导致铸坯缺陷则需采用控热能力更均匀更强的保护渣。

High speed casting is attracted much attention of people for its efficient production.In which,compact strip production(CSP)is the typical casting technology,which casting speed of 3~6 m/min,even up to 9 m/min.The requirements of the mold fluxes become quite strict because that many parameters in the mold have been changed with the improvement of the casting speed.In this paper,the mold flux of medium carbon steel for CSP was studied and its properties were compared with the mold flux for traditional low speed casting.The results show that the mold flux for high speed casting of medium carbon steel needed better lubrication,and the viscosity at 1300℃should be lower than 0.086 Pa·s(casting speed:3.5 m/min).The horizontal heat flux from solidified shell to the mold wall has increased greatly due to the high speed casting.In order to avoid the bad quality of the casting billet caused the fast heat transfer due to the high speed casting,the mold flux which had more uniform and stronger ability to control the heat should be applied.