芯棒直径对楔横轧5Cr21Mn9Ni4N空心气门壁厚均匀性的影响规律

发布时间：2018-06-07 20:00

本文选题：楔横轧 + 耐热钢　；参考：《工程科学学报》2017年02期

【摘要】：楔横轧空心轴类件存在壁厚分布不均问题,特别是在小直径大长径比空心件楔横轧成形中更为突出.本文在Gleeble-1500D热模拟实验机上进行了5Cr21Mn9Ni4N耐热钢的热压缩实验,得到了5Cr21Mn9Ni4N的热变形本构方程.通过改变芯棒直径,采用有限元仿真和实验相结合的方法,研究了楔横轧轧制空心气门过程中的壁厚变化规律.研究结果表明,带芯棒轧制时,芯棒直径存在临界值,在该值下进行轧制,空心气门预制坯壁厚均匀性最优;楔横轧空心件时,金属轴向均匀流动是壁厚均匀的必要条件;轧件轴向拉应变减小,径向压应变变大,周向应变在0附近且为拉应变时,壁厚较为均匀.
[Abstract]:The uneven distribution of wall thickness exists in the hollow shaft type of cross wedge rolling, especially in the forming of small diameter and large diameter, which is more prominent than that of hollow part in cross wedge rolling. The thermal compression test of 5Cr21Mn9Ni4N heat resistant steel was carried out on Gleeble-1500D thermal simulation machine. The thermal deformation constitutive equation of 5Cr21Mn9Ni4N was obtained. By changing the diameter of mandrel and combining finite element simulation with experiment, the variation of wall thickness in the process of cross wedge rolling hollow valve was studied. The results show that there is a critical value for the diameter of the mandrel in rolling with mandrel, under which the uniformity of the wall thickness of the hollow valve prefabricated billet is optimal, and the uniform flow of the metal in axial direction is the necessary condition for the uniform wall thickness of the hollow parts in cross wedge rolling. The axial tensile strain decreases and the radial compressive strain increases. When the circumferential strain is near 0 and is tensile strain, the wall thickness is more uniform.
【作者单位】：北京科技大学机械工程学院;
【基金】：国家自然科学基金资助项目(51375042);国家自然科学基金青年基金资助项目(51505026) 广东省“扬帆计划”资助项目(201312G02)
【分类号】：TG335.19

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