调质态07MnNiMoDR钢脆性断裂机制及冲击功离散性

发布时间：2019-07-07 20:08

【摘要】：测试了调质态07MnNiMoDR钢的冲击功,研究了其在DBTT区间的脆性断裂机制.结果表明,调质态07MnNiMoDR钢在DBTT区间的解理断裂由贝氏体束尺寸控制;存在一个临界尺寸,当形成于贝氏体束内的微裂纹尺寸达到这个临界值,并在正应力作用下穿过贝氏体束界扩展至相邻贝氏体束时,发生脆性解理断裂.另外,在DBTT区间的冲击断裂过程中,粗大贝氏体束的离散分布将使得脆性断裂载荷值不稳定,并最终导致冲击功出现离散.因此,通过控制调质态07MnNiMoDR钢中贝氏体束尺寸并使其均匀分布,能够有效提高其在DBTT区间的冲击功及降低冲击功离散性.
文内图片：

图片说明：－60℃下不同冲击功的载荷－位移曲线及典型载荷－位移曲线示意图
[Abstract]:The impact work of quenched 07MnNiMoDR steel was measured and its brittle fracture mechanism in DBTT range was studied. The results show that the cleavage fracture of quenched and tempered 07MnNiMoDRsteel in DBTT range is controlled by the size of bainite beam, and there is a critical size, when the microcrack size formed in bainite beam reaches this critical value and extends through bainite beam boundary to adjacent bainitic beam under normal stress, brittle cleavage fracture occurs. In addition, in the process of impact fracture in DBTT interval, the discrete distribution of coarse bainite beam will make the load value of brittle fracture unstable, and eventually lead to the discretization of impact work. Therefore, by controlling the size and uniform distribution of bainite bundles in the tuned 07MnNiMoDRsteel, the impact work in the DBTT region can be effectively improved and the dispersion of the impact energy can be reduced.
【作者单位】：上海交通大学材料科学与工程学院;东北大学冶金学院;宝山钢铁股份有限公司研究院;
【基金】：国家自然科学基金资助项目(2011CB610405) 上海宝钢钢铁研究院压力容器发展研究项目(X08ECEJ190)
【分类号】：TG142.1

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