Cu-17Ni-3Al-X合金在中性盐雾中的腐蚀行为

摘要

采用中性盐雾加速试验、扫描电镜、X射线衍射仪、光电子能谱仪等研究了Cu-17Ni-3Al-X合金在中性盐雾中的腐蚀行为.结果表明:在中性盐雾腐蚀过程中,该合金具有良好的耐盐雾腐蚀性能,合金的腐蚀速率随腐蚀时间的延长而迅速降低,腐蚀480 h后平均腐蚀速率仅为0.010 mm/a.这是因为腐蚀后合金表面生成一层致密的Cu2O膜,随着腐蚀的进行,Cu2O膜增厚,同时外层的Cu2O膜被进一步氧化生成疏松的Cu2(OH)3Cl颗粒.合金在中性盐雾中腐蚀后,主要是α(Cu)固溶体被腐蚀,合金中的第二相仍残留在晶界处.%The corrosion behavior of the Cu-17Ni-3Al-X alloy was investigated by means of neutral salt spray test, scanning electronic microscope, X-ray diffraction and X-ray photoelectron spectroscope. The results show that the alloy possesses great resistance to the salt atmosphere. The corrosion rate of the alloy decreases rapidly with the increase of exposure time. After being corroded for 480 h, the average corrosion rate is only 0.010 mm/a. Due to the uniform Cu2O film formed on the surface of the specimen, the underlying substrate is well protected and the corrosion rate of the alloy is highly reduced. With the increase of the exposure time, the Cu2O film is thickened and the outer layer of the Cu2O film is oxidized to granular Cu2(OH)3Cl film. The corrosion in neutral salt atmosphere occurs mainly in α(Cu) matrix of the samples. However, the second phases remain at the grain boundary.