| 引用本文: | 唐 荻,杨 柳,武会宾,郑宏伟,蒋金星,刘丽华.微观组织对贝氏体钢疲劳裂纹扩展行为的影响[J].材料科学与工艺,2013,21(6):60-65.DOI:10.11951/j.issn.1005-0299.20130611. |
| TANG Di,YANG Liu,WU Hui-bin,ZHENG Hong-wei,JIANG Jin-xing,LIU Li-hua.Effects of microstructure on fatigue crack propagation behavior of bainite steel[J].Materials Science and Technology,2013,21(6):60-65.DOI:10.11951/j.issn.1005-0299.20130611. |
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| 摘要: |
| 为了研究组织对疲劳裂纹扩展行为的影响,对3种不同贝氏体组织钢进行了疲劳裂纹扩展实验,并采用SEM和EBSD等方法对裂纹进行了分析．结果表明,板条贝氏体组织在近门槛区和稳定扩展区阻碍裂纹扩展的能力最强,具有最小的裂纹扩展速率．板条贝氏体组织中的大角度晶界使裂纹更容易发生偏折,导致断口表面粗糙度增加,裂纹扩展受到较强的粗糙度诱导裂纹闭合效应的作用．随着ΔK的增大,塑性诱导裂纹闭合效应取代粗糙度诱导裂纹闭合效应开始占据主导作用,是板条贝氏体组织中裂纹扩展速率对ΔK的变化较敏感的原因． |
| 关键词: 金属材料 贝氏体钢 疲劳裂纹扩展速率 疲劳裂纹的偏折 粗糙度诱导裂纹闭合 |
| DOI：10.11951/j.issn.1005-0299.20130611 |
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| 基金项目:国家高技术研究发展计划资助项目(2012AA03A508). |
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| Effects of microstructure on fatigue crack propagation behavior of bainite steel |
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TANG Di1, YANG Liu1, WU Hui-bin1, ZHENG Hong-wei1, JIANG Jin-xing1, LIU Li-hua2
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(1.Research Institute of Metallurgical Engineering, University of Science and Technology Beijing, Beijing 100083, China;;2.Nanjing Iron ＆ Steel Co., Ltd. Development Center, Nanjing 210035, China)
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| Abstract: |
| To research the effects of microstructure on the fatigue crack propagation (FCP) behavior, three kinds of bainite steels with different microstructure were studied by FCP test, and the crack was analyzed with SEM and EBSD. Results show that the lath bainite has the strongest ability to hinder the FCP and the minimum FCP rate at the near-threshold and stable propagation areas. The high-angle boundaries in the lath bainite microstructure make the fatigue crack deflecting easier, which leads to the fracture surface more roughness and promotes the RICC. With the increasing of ΔK, the RICC decreases and the PICC plays a leading role during the FCP gradually, and this is an essential reason why the FCP rate in the lath bainite is sensitive to the change of ΔK. |
| Key words: metal material bainite steel fatigue crack propagation rate deflection of fatigue crack roughness-induced crack closure |
