In here, we report on the pulse electrodeposition of nickel–chromium–phosphorous (Ni–Cr–P) coatings on AISI 1020 low carbon steel using an aqueous electrolyte consisting of NiCl₂, CrCl₃, and NaH₂PO₂. We evaluated the effectiveness of Ni–Cr–P coatings for polymer electrolyte membrane fuel cell metallic bipolar plates. Coatings deposited at pH 3.0 and room temperature show nearly three orders improvement in corrosion resistance compared to bare AISI 1020. The corrosion current (I_corr) of Ni–Cr–P samples coated at 25 °C is 1.16 × 10⁻⁴ A/cm², while that of bare carbon steel is 1.05 × 10⁻² A/cm². The improvement in corrosion resistance is due to the increase in Cr content in the Ni–Cr–P coatings. Cr forms a stable oxide barrier layer and inhibits pitting corrosion. The interfacial contact resistance increases with an increase in Cr content and immersion time in the corrosion media. The increase in interfacial contact resistance is also due to the formation of a stable oxide barrier.

中文翻译：

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Cr含量对PEMFC金属双极板Ni-Cr-P涂层耐蚀性的影响

在这里，我们报告了在AISI 1020低碳钢上使用由NiCl ₂，CrCl ₃和NaH ₂ PO ₂组成的水性电解质在镍-铬-磷（Ni-Cr-P）涂层上进行脉冲电沉积的过程。我们评估了Ni-Cr-P涂层对聚合物电解质膜燃料电池金属双极板的有效性。与裸露的AISI 1020相比，在pH 3.0和室温下沉积的涂层的耐腐蚀性提高了近三个数量级。在25°C的温度下涂覆的Ni–Cr–P样品的腐蚀电流（I _corr）为1.16×10 ^-4 A / cm ²，而裸碳钢的为1.05×10 ^-2 A / cm ²。耐腐蚀性的提高归因于Ni–Cr–P镀层中Cr含量的增加。Cr形成稳定的氧化物阻挡层并抑制点蚀。界面接触电阻随Cr含量的增加和在腐蚀介质中的浸没时间的增加而增加。界面接触电阻的增加也是由于形成稳定的氧化物阻挡层。