A Novel Mo and Nb Microalloyed Medium Mn TRIP Steel with Maximal Ultimate Strength and Moderate Ductility
A Novel Mo and Nb Microalloyed Medium Mn TRIP Steel with Maximal Ultimate Strength and Moderate Ductility
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DOI：
10.1007/s11661-014-2504-x
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发表时间：
2014-11-01
影响因子：
2.8
通讯作者：
Hodgson, Peter D.
中科院分区：
文献类型：
--
作者：
Cai, Minghui;Li, Zhun;Hodgson, Peter D.
通过热力学计算结合实验分析，设计了一种新型相变诱导塑性（TRIP）钢（Fe-0.17C-6.5Mn-1.1Al-0.22Mo-0.05Nb，wt pct）的多相、亚稳态和多尺度（M-3）结构。在这项研究中，Mo和Nb微合金化用于控制残余奥氏体的分数及其拉伸变形过程中的机械稳定性，并提高屈服强度。开发了热力学计算以确定临界退火温度，在该温度下，通过溶质富集的作用将获得大部分残余奥氏体（类似于 38%）。实验观察与预测结果非常吻合。根据临界退火温度，成功获得了具有最佳机械稳定性的超细（< 200 nm）M-3 微观结构。这项工作的结果证明了与其他 TRIP 钢相比具有优越的性能，屈服强度提高到 1020 至 1140 MPa，延展性优异 (> 30 pct)。采用角度选择性背散射和电子背散射衍射技术来解释从变形马氏体板条到超细奥氏体和铁素体双相结构的转变。
The multi-phase, metastable, and multi-scale (M-3) constitution of a novel transformation-induced plasticity (TRIP) steel (Fe-0.17C-6.5Mn-1.1Al-0.22Mo-0.05Nb, wt pct) was designed through thermodynamic calculations combined with experimental analysis. In this study, Mo and Nb microalloying was used to control the fraction of retained austenite and its mechanical stability during tensile deformation and to improve the yield strength. Thermodynamic calculations were developed to determine the critical annealing temperature, at which a large fraction of retained austenite (similar to 38 pct) would be obtained through the effects of solute enrichment. The experimental observation was in good agreement with the predicted results. According to the critical annealing temperature, such an ultrafine (< 200 nm) M-3, microstructure with optimum mechanical stability was successfully achieved. The results of this work demonstrated the superior performance with improved yield strength of 1020 to 1140 MPa and excellent ductility (> 30 pct), as compared with other TRIP steels. Both angle-selective backscatter and electron backscatter diffraction techniques were employed to interpret the transformation from the deformed martensitic laths to the ultrafine austenite and ferrite duplex structure.