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采用扫描电子显微镜(SEM)和光学显微镜(OM)观察辐照后反应堆压力容器焊材EG-F2N钢冲击试样的断口、显微组织及缺陷等,结果表明:冲击数据异常的原因与断口表面存在较多较大孔洞有关,由于孔洞所占体积百分比较大,不仅减小焊缝的有效工作断面,也带来了应力集中,从而显著降低了焊缝冲击试样的强度和韧性;同时在一些小孔洞内发现了Al_2O_3夹杂物,但在焊缝断口附近表面上仅在少量的小孔洞内发现了氧化物夹杂,夹杂物小于0.5级,分析认为Al_2O_3夹杂物的存在不是造成焊缝试样冲击能量值偏低的主要原因,而焊接工艺操作不当造成焊缝中存在较大孔洞才是引起冲击数据异常的主要原因。
The fracture, microstructure and defects of EG-F2N steel samples irradiated by irradiated reactor pressure vessel were observed by scanning electron microscope (SEM) and optical microscope (OM). The results show that the reason of the anomalous impact data and the fracture surface There are many larger holes, due to the larger percentage of the volume of the hole, not only reduce the effective working section of the weld, but also brought the stress concentration, thereby significantly reducing the strength and toughness of the weld impact specimen; Al 2 O 3 inclusions were found in some small holes, but oxide inclusions were found only in a small number of small holes near the fracture surface of the weld. The inclusions were less than 0.5. It was considered that the existence of Al 2 O 3 inclusions did not result in the weld samples Impact energy value is the main reason for the low, and improper operation of the welding process caused by the existence of larger holes in the weld is the main reason for the impact of data anomalies.