Variant selection of lath martensite and bainite transformation in low carbon steel by ausforming
Variant selection of lath martensite and bainite transformation in low carbon steel by ausforming
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DOI：
10.1016/j.jallcom.2011.12.111
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发表时间：
2013-11
影响因子：
6.2
通讯作者：
G. Miyamoto;N. Iwata;Naoki Takayama;T. Furuhara
中科院分区：
文献类型：
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作者：
G. Miyamoto;N. Iwata;Naoki Takayama;T. Furuhara
应用奥氏体取向重构方法，定量分析了低合金低碳钢在形变过程中板条马氏体和贝氏体的变种选择。结果表明，马氏体形变和贝氏体形变均可形成沿压轴方向具有{1+1}α和{0+1+1}α的相变织构。这种织构的发展可以从奥氏体形变织构的角度定性地解释，而不考虑变种选择。然而，它们的强度不能定量地再现，这表明通过形变可以有利地选择特定的变体。定量分析表明，习惯面几乎平行于奥氏体主滑移面和二次滑移面的马氏体变异体优先形成。奥氏体化贝氏体也有类似的变型选择规律，但不如奥氏体强。提出了一种奥氏体形变的择优形核模型，即在奥氏体微带边界上压缩引入的习惯面与奥氏体主滑移面或二次滑移面几乎平行的形核模型。
Variant selection of lath martensite and bainite transformed in an ausformed low-alloy low-carbon steel is analyzed quantitatively by applying reconstruction method of austenite orientation. It was found that transformation texture having {1 1 1}αand {0 1 1}αalong compression axis is developed by ausforming both in martensite and bainite transformation. Development of such texture can be explained qualitatively from deformation texture in austenite without taking variant selection into account. However, their intensities cannot be reproduced quantitatively, indicating that specific variants are favorably selected by ausforming. Quantitative analyses of variant fractions revealed that martensite variants whose habit planes are nearly parallel to the primary and secondary slip planes in austenite are formed preferentially. Similar variant selection rule is observed in ausformed bainite while it is not as strong as in ausformed martensite. A preferential nucleation model is proposed for variant selection by ausforming in which variants with habit planes nearly parallel to the primary or secondary slip planes in austenite are nucleated on the microband boundaries in austenite introduced by compression.