Time-dependent corrosion behavior of electroless Ni–P coating in H2S/Cl− environment
Time-dependent corrosion behavior of electroless Ni–P coating in H2S/Cl− environment
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DOI：
10.1016/j.ijhydene.2021.01.053
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发表时间：
2021-02
影响因子：
7.2
通讯作者：
Longyi Li;Jun Wang;Jie Xiao;Jielu Yan;H. Fan;Lan Sun;Ling Xue;Zhenghua Tang
中科院分区：
文献类型：
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作者：
Longyi Li;Jun Wang;Jie Xiao;Jielu Yan;H. Fan;Lan Sun;Ling Xue;Zhenghua Tang
化学镀Ni-P合金镀层作为一种成熟的技术，因其优异的耐蚀性而被广泛应用于化工设备和管道的防护，但在高含硫油气领域的应用及长期使用评价尚不多见。为此，采用表面分析法研究了L360钢表面Ni-P镀层在饱和H2S介质中的腐蚀行为。结果表明，与未镀Ni-P的管线钢相比，镀Ni-P的管线钢在52.6 μm左右的镀层能显著降低腐蚀速率。这与表面上致密的保护膜的结构有关。未涂层管线钢在浸泡过程中发生局部腐蚀，随后发展为均匀腐蚀，形成大量腐蚀产物。相比之下，Ni-P涂层的腐蚀相对温和，只有一个薄的腐蚀层。然而，在长时间的腐蚀试验中，腐蚀性介质在固有缺陷处渗透涂层/基体界面，导致基体的严重局部腐蚀。
As a mature technology, electroless Ni–P alloy coating is widely applied in the protection of chemical equipment and pipelines owing to its excellent corrosion resistance, but its application and long-term service evaluation in the field of high-sulfur oil and gas are rare. Therefore, the time-dependent corrosion behavior of Ni–P coating, which was plated on the L360 steel surface, was investigated in a saturated H2S medium by the method of surface analysis. The results indicate that Ni–P coating with a thickness of about 52.6 μm could significantly reduce the corrosion rate compared with uncoated pipeline steel. This is related to the structure of the dense, protective film on the surface. The uncoated pipeline steel suffered local corrosion during the immersion process, and then it developed into uniform corrosion with the formation of a large number of corrosion products. In comparison, Ni–P coatings corroded relatively mildly with only a thin corroded layer. However, during prolonged corrosion testing, the corrosive medium penetrated the coating/substrate interface at inherent defects, leading to severe local corrosion of the substrate.