简化退火高强度冷镦钢SCM435盘条的研制

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

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%。

The qb5.0 ～ 22.0 mm wire coils of 0. 35 C 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 roiling and cooling process. The oxygen content in cast billet was 18 × 10^-6 by LF refining with Ar stirring, 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 roiling and cooling process decreased by 50% than that by normal rolling process.