热带轧机轧辊表面氧化膜疲劳脱落的有限元分析

根据热带轧机工作辊与支撑辊之间的接触应力、带钢与工作辊之间的应力,以及轧制过程中的轧辊热应力解析结果,利用大型有限元分析工具ANSYS分析了热轧带钢轧辊的表面氧化膜疲劳脱落问题·结果表明,随着加载次数的增加,氧化膜在原有微裂纹处沿X方向的疲劳应力增加,这将导致在原有微裂纹处沿Y方向产生疲劳裂纹·在氧化膜与轧辊基体的结合面上,由于剪切应力的增加将发生沿轧辊氧化膜与轧辊基体结合部位X方向疲劳裂纹·由于X方向疲劳裂纹和Y方向疲劳裂纹的不断扩展,使得裂纹相遇而导致了轧辊表面氧化膜的脱落·

Finite Element Analysis of Fatigue Deterioration at the Black Oxide Layers on Roll Surface

The fatigue deterioration of black oxide layer on roll surface was analyzed by ANSYS FEM software using the data of contact stress between work roll and back up roll, and the thermal stress of the work roll during hot strip rolling. It is shown that with the increasing of load cycle, the fatigue stress in X direction near roll microcrack is increased. The stress will result in fatigue crack nucleation near the microcrack of the roll surface in Y direction. In the interface between black oxide layer and roll matrix, fatigue crack in X direction is gradually formed with increasing of the shear stress. The propagation of the cracks results in the coalescence of them both in X direction and Y direction. Then, a piece of black oxide layer may be falled off from the roll surface during hot strip rolling.