On the effect of long-term creep on the microstructure of a 12% chromium tempered martensite ferritic steel
On the effect of long-term creep on the microstructure of a 12% chromium tempered martensite ferritic steel
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DOI：
10.1016/j.actamat.2009.07.010
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发表时间：
2009-10-01
期刊：
影响因子：
9.4
通讯作者：
Eggeler, G.
中科院分区：
文献类型：
--
作者：
Aghajani, A.;Somsen, Ch.;Eggeler, G.
在本研究中，我们研究了12%Cr回火马氏体铁素体钢在长期时效和蠕变条件下（823 K，120 MPa，t（R）= 139，971 h）的显微组织演变。我们展示了亚晶粒是如何变粗的，碳化物和亚晶界之间的密切相关性在长期蠕变过程中松动，小角度边界的频率增加。所有这些基本变形过程已在短期蠕变研究中讨论。目前的研究表明，他们也治理长期蠕变。然而，在长期蠕变期间，发生在短期蠕变期间未观察到的沉淀和粗化反应。在长期蠕变后，识别出三种类型的颗粒（M23 C6，VX和Laves相）。M23 C6颗粒在恒定体积分数下粗化，并在51，072 h后建立其平衡浓度; VX颗粒稳定; Laves相颗粒从未达到热力学平衡。(C)2009 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
In the present study we investigate the evolution of the microstructure of a 12% Cr tempered martensite ferritic steel under conditions of long-term aging and creep (823 K, 120 MPa, t(R) = 139,971 h). We show how subgrains coarsen, that the close correlation between carbides and subgrain boundaries loosens during long-term creep and that the frequency of small-angle boundaries increases. All these elementary deformation processes have been discussed in short-term creep studies. The present study shows that they also govern long-term creep. However, during long-term creep, precipitation and coarsening reactions occur that are not observed during short-term creep. Three types of particles (M23C6, VX and Laves-phase) were identified after long-term creep. M23C6 particles coarsen at constant volume fraction and establish their equilibrium concentration after 51,072 h; VX particles are stable; and the Laves-phase particles never reach thermodynamic equilibrium. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.