1500MPa超高强马氏体钢回弹影响因素分析

Analysis of influencing factors of 1500MPa ultra high strength martensitic steel rebound

为了研究1500MPa超高强钢的弯曲回弹性能,提升超高强钢的冷弯成型、冲压等回弹控制精度,本文对1500 MPa冷轧酸洗的超高强马氏体钢进行了三点弯曲试验,评价了超高强钢的弯曲回弹性能。基于三点弯曲试验装置的几何原理,设计了可在线测量样件弯曲角度的仿真模型,实现了对样件弯曲角度的精准测量。通过对比弯曲和回弹角度,分别分析了压下速度、厚度、弯曲半径和相对弯曲半径对材料的弯曲回弹性能的影响。结果表明,1500 MPa超高强马氏体钢随着压下速度的增加,回弹角度略有增大,速度为20 mm/min时回弹最稳定;厚度增加,回弹减小;弯曲半径增大,回弹增大;相对弯曲半径为定值时,回弹程度不同。对比各因素对材料弯曲回弹性能的影响,板厚与弯曲半径同样变化60%的前提下,材料的弯曲回弹改变比例相差36%,板厚是影响超高强钢回弹的最主要因素。

Athree-point bending test of 1500 MPa cold-rolled and pickled ultra high strength steel iscarried out,and the bending rebound performance of ultra high strength steel is evaluatedin order to study the bending rebound performance of 1500 MPa ultra high strength steel and to improve the rebound control accuracy of cold bending forming and stamping of ultra high strength steel.A simulation model for on-line measurement of the bending angle isestablished,and the accurate measurement of the bending angle isrealizedbased on the geometrical principle of the three-point bending test device.The influenceof pressure velocity,thickness,bending radius and relative bending radius on the elastic energy of bending are analyzed by comparing bending and rebound angles.Theanalysis results show that the rebound angle of 1500 MPa ultra high strength martensitic steel increases slightly with the acceleration of the punch speed,and the rebound is most stable when the speed is 20 mm/min.As the thickness increases,the rebound decreases.As the bending radius increases,the rebound increases.When the relative bending radius is fixed,the degree of rebound is different.When the thickness and bending radius change 60%separately,there is a 36%difference in the change ratio of rebound.Comparing the influence of various factors on the elastic energy of bending,it is found thatthe material thickness is the most important factor affecting the rebound of ultra high strength steel.