X80钢孔洞体胞模型及孔洞演化数值分析

发布时间：2018-01-21 03:31

本文关键词： 孔洞演化体胞模型有限元模拟应力三轴度韧性断裂　出处：《钢铁》2017年01期 　论文类型：期刊论文

【摘要】：采用扫描电镜和图像分析对高强韧X80管线钢的拉伸断口特征进行观察以及统计分析,根据断口特征参数设计孔洞体胞模型,并应用有限元数值模拟计算研究孔洞扩张比的演化规律。结果表明,在低应力三轴度的条件下,随着等效应变的增加,夹杂物导致的孔洞体积扩张比也不断缓慢增加,等效应变与孔洞体积扩张比的自然对数成正比,线性关系吻合良好,在后期高应力作用下应考虑M-A岛二次形核形成的孔洞片导致韧性断裂。在任何加载的条件下,对于高的应力三轴度,有限元数值模拟计算孔洞扩张比的演化规律与传统的R-T模型有较大的差异,夹杂物导致的孔洞体积扩张比迅速增加,最终由孔洞间韧带颈缩引起韧性断裂。
[Abstract]:The tensile fracture characteristics of high strength and toughness X80 pipeline steel were observed and statistically analyzed by scanning electron microscope and image analysis, and the pore cell model was designed according to the characteristic parameters of fracture surface. The evolution law of void expansion ratio is studied by finite element numerical simulation. The results show that under the condition of low stress triaxiality, the equivalent strain increases with the increase of equivalent strain. The void volume expansion ratio caused by inclusions also increases slowly, and the equivalent strain is in direct proportion to the natural logarithm of the void volume expansion ratio, and the linear relationship is in good agreement. Under the action of post-high stress, it is necessary to consider the ductile fracture caused by the formation of the secondary nucleation of M-A island. Under any loading conditions, the stress is triaxially high. The evolution law of the finite element numerical simulation for calculating the void expansion ratio is quite different from the traditional R-T model. The volume expansion ratio of the pore caused by inclusions increases rapidly and finally ductile fracture is caused by the necking of the ligaments between the holes.
【作者单位】：武汉科技大学耐火材料与冶金国家重点实验室;武汉钢铁(集团)公司研究院;
【分类号】：TG142.1
【正文快照】： 对于较高韧性的金属材料,小试样测试的断裂韧性指标J1c和CTOD已完全失效,取而代之的是郑长卿等在大量试验基础上提出的临界孔洞扩张比VGC[1],并且十分理想地应用到一些中低韧性的材料中。在早期的孔洞形核扩张研究工作[2-5]中,通常假设基体材料为理想塑性材料,孔洞呈均匀分布

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