Multiscale 3D analysis of creep cavities in AISI type 316 stainless steel
Multiscale 3D analysis of creep cavities in AISI type 316 stainless steel
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DOI：
10.1179/1743284714y.0000000639
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发表时间：
2015-03-01
影响因子：
1.8
通讯作者：
Withers, P. J.
中科院分区：
文献类型：
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作者：
Burnett, T. L.;Geurts, R.;Withers, P. J.
从电厂蒸汽箱中取出的AISI型316不锈钢样品显示再热开裂，并通过微尺度x射线计算机断层扫描（CT），纳米尺度连续截面聚焦离子束扫描电子显微镜（FIB-SEM），能量色散x射线（EDX）光谱成像和透射电子显微镜（TEM）进行了检查。使用相关层析成像的多尺度三维分析可以发现关键区域，并用高分辨率技术进行分析。分析的晶界由微米尺寸的面状腔、M23C6碳化物、铁素体和G相装饰，但没有sigma相。晶粒内的M23C6颗粒也较小，接近晶界。这种密切共存表明，二次相将控制空腔的形核和生长。目前的空化模型基于孤立的理想晶界空腔，过于简化。
A sample of AISI type 316 stainless steel from a power station steam header, showing reheat cracking, was removed from service and has been examined by a combination of microscale Xray computed tomography (CT), nanoscale serial section focused ion beam-scanning electron microscopy (FIB-SEM), energy dispersive X-ray (EDX) spectrum imaging and transmission electron microscopy (TEM). Multiscale three-dimensional analysis using correlative tomography allowed key regions to be found and analysed with high resolution techniques. The grain boundary analysed was decorated with micrometre sized, facetted cavities, M23C6 carbides, ferrite and G phase but no sigma phase. Smaller intragranular M23C6 particles were also observed, close to the grain boundaries. This intimate coexistence suggests that the secondary phases will control the nucleation and growth of the cavities. Current models of cavitation, based on isolated idealised grain boundary cavities, are oversimplified.