Ni-Cu-P合金镀层在燃气冷凝换热器上的应用

研究硫酸铜镀液中浓度对Ni-Cu-P合金镀层的成分、组织结构及耐腐蚀性能的影响.EPMA、XRD和极化曲线镀层测试表明,以浓度为0.5g.L-1的硫酸铜作镀液镀层的耐蚀性能最优.在天然气冷凝液中考察了Ni-Cu-P、Ni-P合金镀层和铜基体的电化学耐腐蚀性能,Ni-Cu-P合金镀层的自腐蚀电位低,自腐蚀电流密度小,交流阻抗值最大.因此该镀层可作为铜质燃气冷凝换热器的耐蚀阻挡层和牺牲阳极保护镀层,防止铜管腐蚀穿孔,有效地延长铜质冷凝换热器的使用寿命.

Applications of Electroless Deposition Ni-Cu-P Coating on the Gas Condensing Exchanger

The effects of copper sulfate concentration in the plating solution on the composition,the structure and the anticorrosion properties of Ni-Cu-P deposited coating were studied by EPMA、XRD and polarization curves.The anticorrosion properties of Ni-Cu-P deposited coating was optimal as the copper sulfate concentration in the plating solution was 0.5 g·L-1.The electrochemical anticorrosion properties of Ni-Cu-P,Ni-P deposited coatings and copper plates were investigated in the gas condensate.The self-corrosion potential of Ni-Cu-P deposited coatings was low,the self-corrosion current density was small,and the electrochemical impedance was the highest.Therefore,the electroless Ni-Cu-P coatings can be used as anticorrosion cover and anodic sacrificial protective coatings of copper condensing exchanger.It could protect copper tubes from being corroded and perforated,so it could increase the effective life of copper condensing exchanger.