南海岛礁环境下304不锈钢腐蚀行为分析  

Corrosion Behavior of 304 Stainless Steel in the Sea Environment of South China Sea

作　　者：段体岗[1] 彭文山 丁康康 郭为民[1] 侯健[1] 孙明先[1] DUAN Ti-gang;PENG Wen-shan;DING Kang-kang;GUO Wei-min;HOU Jian;SUN Ming-xian(State Key Laboratory for Marine Corrosion and Protection,Luoyang Ship Material Research Institute,Qingdao 266237,China)

机构地区：[1]中国船舶重工集团公司第七二五研究所海洋腐蚀与防护重点实验室,山东青岛266237

出　　处：《装备环境工程》2021年第11期51-57,共7页Equipment Environmental Engineering

摘　　要：目的研究304不锈钢材料在南海岛礁大气、飞溅、潮差和全浸区环境下暴露0.5 a的腐蚀行为与规律。方法通过实海环境适应性试验,获取304不锈钢材料在南海岛礁环境下的腐蚀数据。通过腐蚀形貌观察,明确304不锈钢的主要腐蚀形式。通过电化学测试分析,评价304不锈钢耐蚀性能,阐明其腐蚀机理。结果304不锈钢在南海岛礁环境下以点蚀为主,4个区带的平均腐蚀速率分别为0.8、1.1、1.3、3.2μm/a,平均点蚀深度分别为13.57、15.26、18.62、2.43μm,最大点蚀深度分别为28.85、35.63、32.93、40.25μm。交流阻抗和Mott-Schottky曲线测试结果显示,四个区带试样的电荷传递阻抗分别为1.27×10^(7)、8.76×10^(6)、7.35×10^(5)和5.76×10^(5)Ω·cm^(2),载流子含量分别为6.56×10^(22)、1.01×10^(23)、2.80×10^(23)和4.15×10^(23) cm^(‒3)。在全浸环境下,304不锈钢钝化膜破损最严重,耐蚀性下降最大。结论在大气区和飞溅区,304不锈钢以点蚀为主,并在固定部位伴随有轻微缝隙腐蚀;在潮差区和全浸区,由于钙镁沉积物和海生物附着,304不锈钢表面形成大量Cl^(‒)饱和、低溶解氧浓度的腐蚀微电池环境,发生了严重的局部腐蚀,且以全浸区最为严重。The corrosion behavior and law of 304 stainless steel material exposed to 0.5 a in the atmosphere,splash zone,tidal range and full immersion zone of the South China Sea are studied.Through the real sea environment adaptability test,the corrosion data of 304 stainless steel material in the South China Sea island reef environment is obtained.Through the observa-tion of the corrosion morphology,the main corrosion form of 304 stainless steel is clear.Through electrochemical test and analysis,the corrosion resistance of 304 stainless steel is evaluated and its corrosion mechanism is clarified.The results show that the corrosion of 304 stainless steels is featured as the pitting corrosion in the reef environment of the South China Sea.The average corrosion rates of 304 stainless steels in the four zones are 0.8,1.1,1.3 and 3.2μm/a,respectively,the average pitting depths are 13.57,15.26,18.62,2.43μm,while the maximum pitting corrosion depths are 28.85,35.63,32.93 and 40.25μm,re-spectively.The test results of electrochemical impedance and Mott-Schottky curve show that the charge transfer of the four zone samples are 1.27×10^(7),8.76×10^(6),7.35×10^(5) and 5.76×10^(5)Ω·cm^(2),respectively.Additionally,the calculated carrier densities of specimens are 6.56×10^(22),1.01×10^(23),2.80×10^(23) and 4.15×10^(23) cm^(‒3),respectively.In the full immersion environment,the 304 stainless steel passivation film was the most damaged and the corrosion resistance decreased the most.For specimens exposed in the atmospheric zone and the splash zone,pitting corrosion is found and,weak crevice corrosion is formed at the fixed position.For those exposed in the tidal zone and the immersion zone,due to the adhesion of calcium-magnesium deposits and marine or-ganism,an amount of corrosion microbatteries are formed featured with saturated-concentration chloride ions and low-concentration dissolved oxygen,more severe pitting corrosion occurs on the surface of 304 stainless steels and even the most severe for the immersion zone.

关 键 词：海洋腐蚀 南海 岛礁环境 304不锈钢 点蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]