Investigation on decomposition behavior of austenite under continuous cooling in vanadium microalloyed steel (30MSV6)
Investigation on decomposition behavior of austenite under continuous cooling in vanadium microalloyed steel (30MSV6)
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DOI：
10.1016/j.matdes.2015.09.046
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发表时间：
2015-12
影响因子：
8.4
通讯作者：
S. H. M. Azghandi;V. G. Ahmadabadi;I. Raoofian;F. Fazeli;M. Zare;A. Zabett;H. Reihani
中科院分区：
文献类型：
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作者：
S. H. M. Azghandi;V. G. Ahmadabadi;I. Raoofian;F. Fazeli;M. Zare;A. Zabett;H. Reihani
本文主要研究了钒微合金钢（30MSV6）在连续冷却转变（CCT）过程中的组织演变及其硬度变化。此外，采用高分辨率膨胀测量法研究了冷却速率和奥氏体晶粒尺寸对钢的CCT行为的影响。定量金相结合扫描电镜（SEM）有效地证实了转变动力学和奥氏体分解产物的膨胀测量。提出了一种半经验模型来预测钢在奥氏体分解过程中的显微组织发展和由此产生的硬度。该模型由铁素体相变开始温度、铁素体生长、珠光体开始温度、珠光体生长、贝氏体开始温度、贝氏体生长、马氏体开始温度和硬度8个子模型组成。利用半经验Johnson-Mehl-Avrami-Kolmogorov （JMAK）方法结合Scheil的可加性方程对铁素体、珠光体和贝氏体的相变组分进行了描述。利用扩散控制模型建立了贝氏体的JMAK速率参数。所提出的模型的预测结果与实验测量结果非常吻合。
In the present study, investigations are focused on microstructural evolution and the resulting hardness during continuous cooling transformation (CCT) in a commercial vanadium microalloyed steel (30MSV6). Furthermore, the effects of cooling rate and austenite grain size (AGS) on CCT behavior of the steel have been studied by employing high-resolution dilatometry. Quantitative metallography accompanied with scanning electron microscopy (SEM) has efficiently confirmed the dilatometric measurements of transformation kinetics and austenite decomposition products. A semi-empirical model has been proposed for prediction of microstructural development during austenite decomposition of the steel and the resultant hardness. The model consists of 8 sub-models including ferrite transformation start temperature, ferrite growth, pearlite start temperature, pearlite growth, bainite start temperature, bainite growth, martensite start temperature and hardness. The transformed fractions of ferrite, pearlite and bainite have been described using semi-empirical Johnson–Mehl–Avrami–Kolmogorov (JMAK) approach in combination with Scheil's equation of additivity. The JMAK rate parameter for bainite has been formulated using a diffusion-controlled model. Predictions of the proposed model were found to be in close agreement with the experimental measurements.