An experimental and modelling study of brittle cleavage crack propagation in transformable ferritic steel
An experimental and modelling study of brittle cleavage crack propagation in transformable ferritic steel
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DOI：
10.1179/026708310x12668415533801
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发表时间：
2011-04
影响因子：
1.8
通讯作者：
G M Hughes;G E Smith;A. Crocker;P. E. J. Flewitt
中科院分区：
文献类型：
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作者：
G M Hughes;G E Smith;A. Crocker;P. E. J. Flewitt
使用工程断裂力学的原理对压力容器、管道和其他工程结构中可能存在的缺陷进行评估。这是必要的，以支持这种方法与理解的基本断裂机制。此外，这些部件中的许多是使用可变形钢制造的。在本文中，作者描述了A508型钢的断裂，热处理产生回火贝氏体显微组织，随后在−196°C下进行冲击试验。特别是，聚焦离子束显微镜已被用来产生高分辨率的断口分析，结合有关的基本微观结构和晶体学的信息。解理裂纹扩展的原奥氏体晶粒，板条包和板条边界的结果进行了描述，然后与多晶钢的脆性解理断裂的三维几何模型的预测。该模型包括一个考虑的板条子结构内的晶粒，是基于Kurdjumov-Sachs取向关系与母奥氏体晶粒。
Flaws that can be present within pressure vessels, pipework and other engineering structures are assessed using the principles of engineering fracture mechanics. It is necessary to support such an approach with an understanding of the underlying fracture mechanisms. Moreover, many of these components are fabricated using transformable steels. In the present paper, the authors describe the fracture of an A508 type steel, heat treated to produce a tempered bainitic microstructure, and subsequently impact tested at −196°C. In particular, focused ion beam microscopy has been used to produce high resolution fractography, combined with information relating to the underlying microstructure and crystallography. The results of cleavage crack propagation across prior austenite grain, lath packet and lath boundaries are described and then correlated with predictions from a three-dimensional geometric model of brittle cleavage fracture in polycrystalline steel. This model includes a consideration of a lath substructure developed within the grains and is based upon a Kurdjumov–Sachs orientation relationship with the parent austenite grain.