Ferrite Formation Behaviors from B1 Compounds in Steels
Ferrite Formation Behaviors from B1 Compounds in Steels
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DOI：
10.2355/isijinternational.51.2036
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发表时间：
2011-12
影响因子：
1.8
通讯作者：
Changjoon Lee;S. Nambu;J. Inoue;T. Koseki
中科院分区：
文献类型：
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作者：
Changjoon Lee;S. Nambu;J. Inoue;T. Koseki
通过将化学纯的B1化合物的单晶颗粒埋入低合金钢中，研究了B1化合物的化学成分对等温贝氏体-铁素体相变过程中晶内铁素体形成的影响。本研究采用了两种与铁氧体具有相似错配的B1化合物TiO和TiN。在贝氏体转变温度以上和以下进行等温转变实验。用扫描电镜和电子背散射衍射仪研究了B1化合物与铁素体、铁素体与奥氏体的取向关系，发现在较高的转变温度下，B1化合物形成铁素体时，B-N取向关系起主导作用，但随着转变温度的降低，也观察到一些不同于Baker-Nutting取向关系的低指数取向关系，这导致与原始奥氏体具有Kurdjumov-Sachs（K-S）取向关系的铁素体形成增加。从TiO的铁素体有更大的取向差角从精确的B-N取向关系，因此往往有K-S取向关系与原奥氏体在较低的转变温度。
The effect of chemical composition of B1 compounds on the formation of intragranular ferrite during isothermal austenite-to-ferrite transformation was investigated by embedding single crystalline grains of chemically pure B1 compounds in low-alloy steel. Two kinds of B1 compounds having similar misfit against ferrite, TiO and TiN, were adopted in this study. Isothermal transformation experiments were carried out both above and below the bainitic transformation temperature. The orientation relationships between compound and ferrite and between ferrite and prior austenite were characterized by scanning electron microscope equipped with electron backscatter diffraction analyzer.It was found that the Baker-Nutting (B-N) orientation relationship played a dominant role in ferrite formation from B1 compounds at higher transformation temperature, but some low-index orientation relationships other than the Baker-Nutting orientation relationship were also observed as the transformation temperature decreased, which led to an increase in ferrite formation having the Kurdjumov-Sachs (K-S) orientation relationship with prior austenite. Ferrites from TiO had larger misorientation angles from the exact B-N orientation relationship and thus tended to have the K-S orientation relationship with prior austenite at lower transformation temperatures.