Martensitic Transformation from Ultrafine Grained Austenite Fabricated by ARB in Fe-24Ni-0.3C
Martensitic Transformation from Ultrafine Grained Austenite Fabricated by ARB in Fe-24Ni-0.3C
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DOI：
10.4028/www.scientific.net/msf.667-669.361
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发表时间：
2010-12
期刊：
影响因子：
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通讯作者：
H. Jafarian;E. Borhani;A. Shibata;D. Terada;N. Tsuji
中科院分区：
文献类型：
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作者：
H. Jafarian;E. Borhani;A. Shibata;D. Terada;N. Tsuji
研究了一种亚稳奥氏体合金中累积叠轧复合（ARB）工艺制备的超细晶（UFG）奥氏体的马氏体相变。用FE-SEM/EBSD对样品进行了微观结构观察和晶体学分析。结果表明，经过6个循环的ARB工艺后，获得了具有200-300 nm厚度的被大角度晶界包围的细长UFG奥氏体。由UFG奥氏体转变的马氏体具有特征的形貌和织构。马氏体相变开始（Ms）温度增加后1个循环ARB，这是有关的形核网站，如小角度边界，在ARB过程的早期阶段引入的数量增加。相反，通过增加ARB循环，Ms温度降低。降低Ms温度可能与ARB工艺强化奥氏体有关。
In this paper, martensitic transformation from ultrafine grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process in a metastable austenite alloy was studied. Microstructural observations and crystallographic analysis were carried out by FE-SEM/EBSD. The results showed that elongated UFG austenite having 200-300 nm in thickness surrounded by high angle boundaries was obtained after 6 cycles of the ARB process. The martensite transformed from the UFG austenite showed characteristic morphology and texture. The martensite transformation starting (Ms) temperature increased after 1 cycle ARB, which is related to increasing amount of nucleation sites, such as low angle boundaries, introduced during early stage of ARB process. In contrast, by increasing the ARB cycles, Ms temperature decreased. Decreasing the Ms temperature could be correlated to strengthening of austenite by the ARB process.