摘要: |
1993年9月-1994年9月在中国科学院海洋研究所培育楼流动海水实验室将普通碳钢(A3钢)和低合金钢(16Mn钢)以分别和电连接两种挂片方式置于海面大气区、海水全浸区和不同的海底沉积物中进行一年的室内模拟实验。结果表明,两种钢在海洋环境中的腐蚀率在分别挂片时呈下列顺序:海面大气区>海水全浸区>海底沉积区;在电连挂片时出现如下顺序:海面大气区>海底沉积区>海水全浸区。随着海底沉积物颗粒度的减小,水/泥(砂)界面腐蚀最轻的钢片的腐蚀速度在电连挂片时成正相关关系,分别挂片时影响不大。处于沉积区最底部的钢片因成为宏电池的阳极,而遭受最严重的腐蚀。低合金钢的腐蚀率比普碳钢略大。 |
关键词: 海底沉积物 钢铁 腐蚀 |
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基金项目:中国科学院“八五”重大课题,Ky85-11号 |
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STUDY ON STEEL CORROSION IN DIFFERENT SEABED SEDIMENT |
Li Yantao, Hou Baorong
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Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071
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Abstract: |
From Sept. 1993 to Sept. 1994 at seawater lab in Institute of Oceanology, Chinese Academy of Sciences, a series of simulated experiments of carbon steel (A3 steel) and low-alloy steel (l6Mn steel) in sea surface atmosphere (SSA), seawater (SW) and seabed sediment (SBS) including coarse sand, fine sand and sea mud were carried out indoor for a year or so by means of individually hanging plates (IHP) and electrically connectedly hanging plates (ECHP). The corrosion of steels in SBS is mainly due to the effect of macrogalvanic cell (oxygen concentration cell). The steel plates at the bottom of SBS, as the anode of the macrogalvanic cell, showed the heaviest corrosion, at corrosion rate of up to 0.12 mm/a, approximately equal to that of steel plates in sea surface atmosphere.
The test results showed that the corrosion rates of two kinds of steel in marine environment were in the order: SSA>SW>SBS by the IHP method, SSA>SBS>SW by the ECHP method. The corrosion rates of steels in the water / sediment interface were directly proportional to the grain-size of the SBS by the ECI-LP, but those of steels in the water / sediment interface did not vary with the grain-size of SBS by the IHP method. The corrosion rate of low-alloy steel was a little higher, instead of lower than that of carbon steel. The results of this study have important applications for design of offshore steel structures, such as oil platform, pier and port. |
Key words: Seabed sediment, Steel, Corrosion |