文献类型：期刊文献

英文题名：Galvanic Corrosion of E690 Offshore Platform Steel in a Simulated Marine Thermocline

作者：Hu, Jiezhen[1,2,3];Lin, Guodong[1];Deng, Peichang[2,4];Li, Ziyun[1];Tian, Yuwan[1,2]

机构：[1]Guangdong Ocean Univ, Coll Mech Engn, Zhanjiang 524088, Peoples R China;[2]Zhanjiang Key Lab Corros & Protect Ocean Engn Equi, Zhanjiang 524088, Peoples R China;[3]Guangdong Prov Ocean Equipment & Mfg Engn Technol, Zhanjiang 524088, Peoples R China;[4]Guangdong Ocean Univ, Coll Chem & Environm, Zhanjiang 524088, Peoples R China

年份：2024

卷号：14

期号：3

外文期刊名：METALS

收录：SCI-EXPANDED(收录号：WOS:001193510400001)、、Scopus(收录号：2-s2.0-85189076904)、WOS

基金：No Statement Available

语种：英文

外文关键词：galvanic corrosion; simulated marine thermocline; E690; dissolved oxygen; exploitation of ocean resource

外文摘要：Marked changes in temperature, pH, dissolved oxygen (DO) content, and nutrient content typically occur in marine thermoclines, which are key factors that affect the corrosion of metals. Offshore platforms require marine metals to be exposed to deep-sea environments and thus increase their penetration into the marine thermocline. This study investigates the galvanic corrosion of E690 steel in a marine thermocline using a simulated marine thermocline (SMT). Specifically, the corrosion of E690 steel was analyzed using the wire beam electrode (WBE) technique, linear polarization (LP), corrosion morphology, and weight loss measurement. Results indicated that the SMT had a stable multilayer structure, and the variations in temperature, DO, pH, and nutrient concentration in the SMT were similar to those in the natural marine thermocline. There were two forms of E690 steel corrosion in the SMT: galvanic corrosion and seawater corrosion. The corrosion rate of seawater corrosion was influenced by the DO concentration. Galvanic corrosion occurred after the intrusion of E690 steel into the marine thermocline. The driver of galvanic corrosion was the difference values for E(corr)s of E690 steel at various depths of the marine thermocline. The E-corr of E690 steel was influenced by the temperature, pH, and DO of the seawater, in the following order: DO >> T > pH. The continuous reduction in E-corr with depth contributed to large-scale galvanic corrosion, and the oscillation variation in E-corr with depth was the reason for small-scale galvanic corrosion. The primary anodic regions of galvanic corrosion were located in the area with the fastest temperature variation in the thermocline, and the position of the anodic regions rose with time. The anodic regions gradually expanded with time. The proportion of galvanic corrosion in the average corrosion rate could increase up to approximately 80% in the stable anodic region. There were many hemispherical corrosion pits on the surface of the single electrodes that were at the depths of 75 cm, 105 cm, and 135 cm. These single electrodes comprised a long-term, sustainable anodic region of galvanic corrosion.