Fatigue crack growth of 316NG austenitic stainless steel welds at 325 °C
Fatigue crack growth of 316NG austenitic stainless steel welds at 325 °C
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DOI：
10.1016/j.jnucmat.2017.11.044
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发表时间：
2018-02
影响因子：
3.1
通讯作者：
Y. Li;J. Xiao;Y. Chen;J. Zhou;S. Qiu;Q. Xu
中科院分区：
文献类型：
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作者：
Y. Li;J. Xiao;Y. Chen;J. Zhou;S. Qiu;Q. Xu
316 NG奥氏体不锈钢是压水堆系统主冷却剂管材的常用材料。这些管道通常通过自动窄间隙焊接工艺连接在一起。采用窄间隙焊接方法对316 NG奥氏体不锈钢管材进行了焊接，并对焊缝组织进行了表征。然后，在325℃下进行了疲劳裂纹扩展试验，在熔合区发现了富含锰和硅的析出物。疲劳裂纹路径为平面外，二次裂纹从析出相/基体界面萌生。在325°CAIR和水(DO=10∼10 Gppb)和f=2 10 HZ时，也观察到裂纹扩展的适度加速。
316NG austenitic stainless steel is a commonly-used material for primary coolant pipes of pressurized water reactor systems. These pipes are usually joined together by automated narrow gap welding process. In this study, welds were prepared by narrow gap welding on 316NG austenitic stainless steel pipes, and its microstructure of the welds was characterized. Then, fatigue crack growth tests were conducted at 325 °C. Precipitates enriched with Mn and Si were found in the fusion zone. The fatigue crack path was out of plane and secondary cracks initiated from the precipitate/matrix interface. A moderate acceleration of crack growth was also observed at 325°Cair and water (DO = ∼10 ppb) withf= 2 Hz.