Investigations on the Temperature for Completion of Austenite Transformation During the Initial Solidification Process of Micro-alloy Steels
Investigations on the Temperature for Completion of Austenite Transformation During the Initial Solidification Process of Micro-alloy Steels
复制标题
微合金钢初始凝固过程中奥氏体相变完成温度的研究
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Li, Yun-Feng
中科院分区：
文献类型：
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作者：
Liu, Jiang;Wen, Guang-Hua;Tang, Ping;Li, Yun-Feng
中碳微合金钢在凝固初期形成的粗大奥氏体晶粒是影响钢横向开裂的重要因素。利用激光共聚焦扫描显微镜观察了P510 L钢的初始凝固过程，考察了δ、γ相的形成和包晶反应，并探讨了γ相变完成的温度。结果表明：艾德：1）在冷却速度为2。5 ℃ / s时，P510 L钢的冷却方式为δ-铁素体先从液相中析出，然后与液相发生包绕反应（L + δ→γ），进入三相共存区。2）在凝固初期，部分奥氏体晶粒先兼并长大，然后残余δ铁素体转变为同素异形奥氏体，最终达到完全奥氏体区; 3）通过原位动态观察，寻求了一种更准确的确定γ相变完成温度的方法，提高了奥氏体晶粒度预测模型的精度。
Coarse austenite grain formed in the initial solidification process is an important factor to affect the transverse cracking of medium carbon micro-alloyed steels. The initial solidification process of P510L steels w ere observed by the confocal laser scanning microscope in order to inspect the formation of δ and γ phases and the peritectic reaction,and explore the temperature for the completion of γ transformation. The results show ed that: 1) With the cooling rate of 2. 5 ℃ / s, the cooling mode of P510L steel w as that δ-ferrite precipitated from the liquid phase first,then the peritectic reaction( L + δ→γ) occured between the δ-ferrite phase and the liquid phase,then they entered to the three-phase coexistence region. With the liquid phase disappeared,the remain δ phase transformed into γ phase by the solid state diffusion; 2) In the initial solidification process, parts of the austenite grains annexed and grew up first,then the remain δ-ferrite transformed into austenite w ith the allotropic heterogeneous,and the fully austenite region achieved at last; 3) A more accurate method about determining the temperature for the completion of γ transformation w as sought by in-situ dynamic observation,and the accuracy of a model for predicting the austenite grain size w as thus improved.