核级ENiCrFe-7镍基合金电焊条的研制

迄今,核电设施的焊接用镍基合金电焊条都依赖进口。为此,成功研制了核级ENiCrFe-7镍基合金电焊条,并在低合金钢板上制备了约20mm厚的堆焊层。随后检测了焊缝金属的宏观和微观形貌及室温和350℃力学性能,并对其进行了弯曲试验、剪切试验、晶间腐蚀试验和STF(strain-to-fracture)试验。结果表明:焊缝金属的宏观质量、微观组织、力学性能和耐晶间腐蚀性能均符合第三代先进压水堆核电站的要求,并且对高温失塑裂纹(DDC)不敏感。新研制的核级ENiCrFe-7镍基合金电焊条的综合性能与进口焊条的相当,有望替代进口的焊条。

Development of Nuclear-grade ENiCrFe-7 Nickel-base Alloy Electrode

Up till now,nickel-base alloy welding electrode used in welding nuclear power facilities are dependent on imports.For this reason,one type of nuclear-grade ENiCrFe-7 nickel-base alloy electrode has been successfullydeveloped,and was used to fabricate an overlay about 20 mm thick on a low-alloy steel plate.After this,the weld metal was tested for low-magnification and higher magnification views,mechanical properties at room temperature and at 350 C,and subjected to bending test,shearing test,intergranular corrosion test,and SIF(strain-to-fracture)test.The results showed that the weld metal exhibited appearance quality,microstructure,mechanical properties and resistance to intergranular corrosion which all conformed with the requirements of the third generation advanced PWR nuclear power plant,and was insensitive to DDC(ductility dip cracking).The newly developed nuclear-grade ENiCrFe-7 nickel-base alloy electrode had comprehensive properties equivalent to those of imported electrodes,and is expected to replace imported one.