研究了 AP1000 上封头 CRDM 管座用焊接镍基合金的电解抛光工艺条件,探讨了电解抛光对其表面粗糙度和应力的改善作用。 结果表明:焊接镍基合金的抛光电流密度应控制在 0 . 3 ~ 0 . 5 A / cm²之间,抛光时间宜为 2 ~ 5 min;电解抛光使表面拉应力大幅度减少,甚至产生压应力,这可抑制焊接镍基合金应力腐蚀开裂

Electro-polishing process for the welding nickel-based alloy of AP1000 upper head CRDM nozzle was studied. The improvement on the surface roughness and residual surface stress were investigated. The results show that the current density should be controlled in the range of 0 . 3 ~ 0 . 5 A / cm²and the polishing time should be within 2 ~ 5 min. The residual stress tests in surface demonstrate that tensile stress is remarkably decreased, and even pressing stress is induced by the electropolishing process, which may restrain the occurrence of stress-corrosion cracking in the welding nickel-based alloy.