低速大压下轧制工艺对钢板性能及质量的影响

Effect of Low Speed and Large Reduction Rolling Process on Mechanical Properties and Quality of Steel Plate

低速大压下轧制是一种广泛用于特厚钢板轧制的工艺,能够使特厚钢板心部发生变形、内部缺陷充分弥合,有效提升特厚钢板性能,减少各种表面质量缺陷。在钢板的热轧塑性变形过程中,同时发生塑性变形引起的加工硬化、回复与再结晶软化过程。通过大压下轧制,能够很好地提高轧制过程各个道次变形渗透率,从而加强塑性变形引起的加工硬化效果;而通过降低轧制速度,可大幅度降低钢板轧制过程中的变形抗力,从很大程度上提高材料塑性,降低大压下引起的轧辊能耗,从而确保大压下轧制的有效进行,减少钢板对轧机工作辊的冲击,避免轧制力和扭矩、电流等急剧增大对轧机工作辊、万向轴等关键部件造成损害。较低的轧制速度也为钢板在轧制过程中实现完全塑性变形提供了充分的时间,轧制速度的降低与大压下相结合,还有利于消除源于炼钢工序的内部裂纹、疏松、孔隙等钢板质量缺陷。

Low speed and large reduction rolling is a widely applied process for extra heavy steel plate,which can make the center of extra heavy steel plate deform,fully fuse the internal defects of steel plate,effectively improve the mechanical properties of extra heavy steel plate and reduce various surface quality defects.During hot rolling plastic deformation,the process of work hardening,recovery and recrystallization softening caused by plastic deformation occurs at the same time.The deformation penetration ratio of each rolling pass is increased by means of large reduction rolling so as to enhance the work hardening effect owing to plastic deformation improvement.The deformation resistance during plate rolling is reduced by lowering the rolling speed,material plasticity is greatly improved in order to cut down the energy consumption of the rolls due to large reduction,ensure effective large reduction rolling,relieve the impact of steel plate on work roll during rolling,avoid the damage on critical parts such as work roll,cardan shaft due to sharp increase of rolling force,torque and current.The lower rolling speed also provides enough time to achieve complete plastic deformation for the steel plate during rolling,which is favorable for the elimination of plate quality defects such as internal cracking,looseness,porosity in combination with large reduction process.