Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels
Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels
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DOI：
10.1016/j.jnucmat.2011.12.004
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发表时间：
2012-06-01
影响因子：
3.1
通讯作者：
Onizawa, K.
中科院分区：
文献类型：
--
作者：
Takeuchi, T.;Kameda, J.;Onizawa, K.
采用原子探针层析成像（APT）技术研究了反应堆压力容器不锈钢埋弧焊堆焊层热老化后的显微组织变化。在所收到的材料进行焊后热处理（PWHTs），与随后的炉冷却，观察到由于在δ-铁素体相，但不是在奥氏体相中的调幅分解的Cr浓度的轻微波动。在400 ℃下热时效10，000 h不仅导致调幅分解的幅度增加，而且在δ-铁素体相中析出了组成比为Ni：Si：Mn = 16：7：6的G相。埋弧焊试样的调幅分解程度与电渣焊试样相似。我们还观察到γ-奥氏体和δ-铁素体界面上的碳化物。碳化物周围没有Cr贫化区。(c)2012爱思唯尔有限公司版权所有。
The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the delta-ferrite phase but not in the austenitic phase. Thermal aging at 400 degrees C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the delta-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the gamma-austenite and delta-ferrite interface. There were no Cr depleted zones around the carbide. (c) 2012 Elsevier B.V. All rights reserved.