Research on Crack Resistance of Nuclear Grade Nickel-Based Alloy Welding Materials

This paper mainly introduces the anti-crack performance of the nuclear grade nickel-based alloy welding materials produced by Baowu Special Metallurgy Co., Ltd. The research materials include welding wires (ERNiCrFe-7A), covered electrodes (ENiCrFe-7) and welding strips (EQNiCrFe-7A) used in PWR nuclear power plants. Evaluation of the anti-crack performance of the deposited metal is mainly carried out from the following three aspects: In order to study the thermal crack (crystal cracks) sensitivity of Baowu nickel-based alloy welding materials, the adjustable constraint test method is used and the results are compared with those of imported commercial welding materials; Based on STF (strain-to-fracture test) experimental method, the sensitivity of ductility dip cracking (DDC) of Baowu and imported nickel-based alloy welding materials is studied by thermal simulation equipment; The stress corrosion cracking (SCC) performance evaluation of Baowu welding materials is carried out by stress corrosion crack propagation experiment in simulated PWR primary water and compared with imported materials respectively. According to the above research, the crystal crack resistance, DDC resistance and SCC resistance of Baowu nickel-based alloy welding materials have reached the level of international high-level commercial welding material, which will further provide experimental data support for the engineering applicability and performance reliability of domestic nickel-based welding materials.