利用研制初期的M公司和R公司两种埋弧焊材,在相同焊接条件下分别埋弧焊接核电站钢安全壳用SA738Gr.B钢。利用光学和扫描电子显微镜探寻组织结构差异,研究焊缝金属冲击功。结果表明:含有大量针状铁素体的焊缝金属组织对微裂纹形成和扩展的阻碍作用较大,可使其冲击功提高。本研究为SA738Gr.B钢埋弧焊材的后续改进提供了依据。目前相关埋弧焊材已研究定型,正在进行用户和第三方国产化评估试验。 The SA738Gr.B steel is used for submerged arc welding of steel containment of nuclear power plant under the same welding conditions by using two kinds of submerged arc welding materials of M company and R company in the initial stage of development. Using optical and scanning electron microscopy to explore differences in organizational structure, weld metal impact energy. The results show that the microstructure of the weld metal containing a large amount of acicular ferrite hinders the formation and propagation of micro-cracks and the impact energy can be improved. This study provides the basis for the subsequent improvement of SA738Gr.B steel submerged arc welding consumables. The relevant submerged arc welding consumables have been studied stereotypes, the user and third party localization assessment.