高强钢生产圆盘剪崩刃原因分析及改进措施

Cause analysis and improvement measures of disc shear tipping during high strength steel production

针对生产高强钢时圆盘剪极易崩刃问题,从带钢强度、圆盘剪材质以及使用方式等多方面对其产生原因进行了分析,并结合圆盘剪三维模型,引入Gissmo材料失效准则计算了圆盘剪剪刃受力。结果表明:高强钢强度高、塑性差,在圆盘剪的作用下不容易产生塑性变形,使剪刃所受应力增大;同时,由于高强钢通常存在边浪缺陷,边浪的存在会打破圆盘剪与带钢边部之间原有的剪切力平衡,带钢与剪刃之间的摩擦力在短时间内迅速增加,促使剪刃局部升温,剪刃软化,导致刃口崩缺。为此,设计了一种上剪刃95°钝角圆盘剪,严格控制带钢板形并坚持“大间隙,小重叠量,稳定速度”的使用原则,钝角圆盘剪寿命较90°圆盘剪提高了13倍以上,且带钢边部剪切质量明显改善。

In view of the problem of the discshear tipping during high strength steel production,the causes of tipping were analyzed from strip strength,disc shear material and usage types.Combined with the three-dimensional model of disc shear,Gissmo material failure criterion was introduced to calculate the disc shear blade stress.The results show that the high strength steel has high strength and poor plasticity,so it is not easy to produce plastic deformation under the action of disc shear,which increases the stress on the shear blade.At the same time,high strength steel usually has edge wave defects,which will break the original shear force balance between disc shear and strip edge,the friction between the strip and the shear blade increases rapidly in a short time,prompting the local heating and softening of the shear blade,leading to the shear tipping.Therefore,a 95°obtuse angle disc shear with upper shear blade is designed,the strip shape is strictly controlled and the principle of“large gap,small overlap,stable speed”is insisted.The life of obtuse disc shear can be increased by more than 13 times of the 90°disc shear,and the trimming quality of strip edge is improved obviously.