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论文类型：期刊论文

发表时间：2019-02-01

发表刊物：MATERIALS CHARACTERIZATION

收录刊物：SCIE、EI

卷号：148

页面范围：52-62

ISSN号：1044-5803

关键字：Cast duplex stainless steel; 3D microstructure; Tomography; Micropore

摘要：Cast duplex stainless steels (CDSS) is being extensively used in many industries. The morphology and distribution of ferrite phase present, as well as the micropores defect, significantly influences the hot cracking susceptibility and corrosion resistance of CDSS. In this work, the microstructure and the micropores of the inner wall and outer wall position of a primary coolant pipe used in the pressurized water reactor (PWR) were characterized and compared using a lab scale X-ray microtomography approach. During centrifugal casting process, the local ferrite grains tend to grow in the same direction. Although the ferrite phases seem separated from each other in a two-dimensional (2D) image, most of them are connected in a three-dimensional (3D) view. Solution treatment can result in homogeneous distribution in both fraction and morphology of ferrite phase. Micropores always form along the ferrite/austenite interface and the inner wall position is more prone to porosity.