简化退火高强度冷镦钢SCM435盘条的研制

马钢采用铁水预处理-50t顶底复吹转炉冶炼-65tLF精炼-6流140mm×140mm方坯连铸-SMS控轧控冷高速线材轧机工艺流程,生产Φ5.0～22.0mm简化退火0.35C高强度冷镦钢SCM435盘条。通过LF精炼及连铸保护浇铸和电磁搅拌,铸坯中氧含量达18×10^-6。经控轧控冷生产的线材抗拉强度平均为746.5MPa,较常规工艺轧制的线材低200MPa。因此,控轧盘条球化退火时间较常规轧制盘条减少50%。

Research and Production of High Strength Cold Heading Steel SCM435 Wire Coil with Short-Time Annealing

The  φ5.0~22.0mm  wire  coils  of 0.35C  high  strength  cold  heading  steel  SCM435  with  short-time  annealing were produced at Ma'anshan Iron and  Steel by hot metal pretreating -50 t top and bottom combined blown converter  melting-65 t LF refining -6  strand  140 mm×140 mm billet concasting -SMS high  speed wire coil mill control rolling and  cooling process. The oxygen content in cast billet was  18×10-⁶ by LF refining with Ar stiring,  sealed and argon  shielding casting and electromagnetic stirring. The average tensile strength of wire produced by control rolling and cooling process was  746.5 MPa which lower 200 MPa than that by normal rolling process,therefore the annealing time of wire coil produced by  control rolling and cooling process decreased by 50% than that by normal rolling process.