Numerical investigation on the effect of skin passing and roller leveling on the bending behaviour of mild steel
Numerical investigation on the effect of skin passing and roller leveling on the bending behaviour of mild steel
复制标题
平整和辊式矫平对低碳钢弯曲性能影响的数值研究
DOI：
10.1063/1.4850011
复制
发表时间：
2013
影响因子：
2.4
通讯作者：
M. Weiss
中科院分区：
文献类型：
--
作者：
Jascha Marnette;B. Rolfe;P. Hodgson;M. Weiss
用于辊轧成形的钢的常见等级是：热轧、高强度低合金和恢复退火的冷轧板。这些钢易于老化，并且通常进行表皮光整和/或辊整平以消除老化，因为这可能导致成形问题。由于材料的弹塑性转变点的改变，形状缺陷例如弯曲、扭曲和翘曲可能增加。考虑到这种影响，如果要精确地模拟这些过程，就必须了解弹塑性转变范围内的材料特性。以前的研究表明，残余应力在标准拉伸试验中不能很好地识别，但在弯曲试验中清楚地显示出来。冷轧压下量对弯曲过程中的弹塑性转变和弯矩曲率特性有显著影响。在这项工作中，有限元分析软件包Abaqus被用来调查的影响，通过平整和/或辊矫直的弯曲/屈服行为的低碳钢引入的残余应力。因此，模拟平整/辊矫直过程，然后进行随后的弯曲测试。将无残余应力板与仅“平整”、“辊轧平整”和"平整+辊轧“组合板在弯曲中进行比较。由于残余应力，蒙皮通过显著降低弯曲屈服应力。这对随后的弯曲操作具有软化作用。在辊轧成形之前的辊级工艺可以通过减小厚度上的残余应力来恢复弯曲屈服应力。这对形成老化材料具有影响。
The common grades of steel used in roll forming are: hot rolled, high strength low alloy and recovery annealed cold rolled sheet. These steels are prone to ageing and are often skin passed and/or roller leveled to eliminate ageing as this can lead to problems in forming. Shape defects such as bow, twist and camber can be increased due to a change of the elastic-plastic transition point of the material. In consideration of this effect the knowledge of the material properties in the elastic plastic transition range is necessary if the processes are to be modelled accurately. Previous studies have indicated that residual stresses are not well identified in the standard tensile test, but were shown clearly in a bending test. The elastic plastic transition in bending and the moment curvature characteristic were changed significantly by a light cold rolling reduction. In this work the FEA package Abaqus is used to investigate the effect of residual stresses introduced through skin passing and/or roller leveling on the bending/yielding behaviour of mild steel. Therefore, a skin passing/ roller leveling process is simulated, followed by a subsequent bending test. Residual stress free sheet is compared in bending to just "skin passed", "roller leveled" and a combined "skin passed and roller leveled" strip. Skin passing significantly reduces the bending yield stress due to residual stresses. This has a softening effect on subsequent bending operations. A roller level process prior to roll forming can restore the bending yield stress by reducing the residual stress across the thickness. This has implications for forming aged material.