摘要
通过光学显微镜(OM)、扫描电子显微镜(SEM)、电化学实验,研究了双相不锈钢SAF 2304的电化学性能及实海腐蚀行为,并与碳钢做了对比。结果表明:碳钢的自腐蚀电位为-0.857 V_(SCE),维钝电流密度为87.30μA·cm^(-2),容抗弧半径较小,耐腐蚀性较差。SAF 2304在3.5%NaCl溶液的开路电位中长期稳定,自腐蚀电位为-0.369 V_(SCE),维钝电流密度为18.03μA·cm^(-2),容抗弧较大。实海暴露实验中,碳钢表面形成了疏松的腐蚀层,而SAF 2304表面在近海暴露前期形成了致密的金属氧化膜,并且随着暴露时间的增加,氧化膜表面附着了一层较为致密的钙镁沉积层和SiO_(2),与不锈钢结合紧密,具有一定保护作用,腐蚀形貌表现为均匀腐蚀,腐蚀速率远小于碳钢,耐蚀性好。
Electrochemical properties and real-sea corrosion behavior of duplex stainless steel SAF 2304 in a test site located in the Zhoushan area of the East China Sea,with a depth of about 10 m were assessed by mean of mass loss measurement,electrochemical tests,optical microscopy(OM)and scanning electron microscopy(SEM)and compared with carbon steel.The electrochemical test results show that the free corrosion potential of carbon steel is-0.857 V_(SCE),the passive current density is 87.30μA‧cm^(-2),the capacitive arc radius is small,and the corrosion resistance is poor.SAF 2304 duplex stainless steel is stable for a long time in the open circuit potential of 3.5%NaCl solution,the free corrosion potential is-0.369 V_(SCE),the passive current density is 18.03μA‧cm^(-2),the capacity of the arc resistance is large,and the corrosion resistance is good.In the real sea exposure experiment,the corrosion rate of SAF 2304 duplex stainless steel is much smaller than that of carbon steel.With the increase of exposure time,a relatively compact scale composed of Ca and Mg containing deposits and SiO_(2)may further form on the preformed metal oxide film,and all the corrosion products are tightly adhered to the substrate,therefore,provides protective effect to a certain extent for the steel,and the corrosion morphology is uniformly corroded.
作者
黄家针
黄涛
杨丽景
季灯平
丁贺
韦一
宋振纶
HUANG Jiazhen;HUANG Tao;YANG Lijing;JI Dengping;DING He;WEI Yi;SONG Zhenlun(College of Chemical Engineering,Zhejiang University of Technology,Hangzhou 310000,China;Key Laboratory of Marine Materials and Related Technologies,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China;Zhejiang Qingshan Iron&Steel Co.Ltd.,Lishui 323903,China)
出处
《中国腐蚀与防护学报》
CAS
CSCD
北大核心
2023年第3期630-638,共9页
Journal of Chinese Society For Corrosion and Protection
基金
浙江省科技计划项目(2022C01192和2021C01082)。
关键词
双相不锈钢
电化学
实海
腐蚀行为
duplex stainless steel
electrochemistry
real sea
corrosion behavior
