表面技术2024，Vol.53Issue(14)：75-86,12.DOI:10.16490/j.cnki.issn.1001-3660.2024.14.006
海洋环境用热轧304L不锈钢-A36碳钢复合钢板的腐蚀行为研究
Corrosion Behaviour of Hot-rolled 304L Stainless Steel-A36 Carbon Steel Composite Steel Plate for Marine Environment
摘要
Abstract
Corrosion is one of the main causes of material failure. Steel components used for marine construction, such as steel supports for coastal airports, steel structures for sea-spanning bridges, offshore platforms and steel plates for island buildings, etc., cause a large amount of economic losses due to corrosion every year. The work aims to investigate the corrosion behavior and corrosion mechanism of cladding, carbon steel substrate and stainless steel-carbon steel composite interface in 304L stainless steel and A36 carbon steel hot-rolled composite steel plate in marine atmospheric environment and seawater immersion environment. Neutral salt spray test and electrochemical test were used to simulate the different marine environments. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the microstructure and local elemental distribution at the composite interface, and X-ray diffractometry (XRD) was used to characterize the composition and valence of the corrosion products. A clear elemental transition region existed at the composite interface. The combination of the two steel composite interfaces was smooth and the bonding quality was good, and rolling had no significant effect on the microstructure at the composite interfaces of the two steels. When the neutral salt spray test was carried out for 96 h, the corrosion rate of the composite interface began to exceed that of the carbon steel substrate. At the end of the test, the corrosion mass loss of the composite interface and carbon steel substrate reached 582 g/m2 and 468 g/m2, respectively, and the corrosion rate of the composite interface in the marine atmosphere was 1.24 times of that of the carbon steel substrate. In addition, a chlorine-rich layer was observed in the corrosion products on the carbon steel side of the composite interface. In electrochemical tests, the composite interface showed smaller impedance than the carbon steel substrate, which resulted in a corrosion rate of 1.13 times that of the carbon steel substrate for the composite interface in seawater immersion environment. The galvanic coupling corrosion effect was found at the composite interface, which accelerated the corrosion of A36 carbon steel. The test results of the OCP showed that carbon steel played a dominant role in the OCP of the exposed surface of the composite steel, and the OCP of the composite interface with different stainless steel-carbon steel area ratios varied less. From the SEM morphology and EDS results of the cladding and composite interface after electrochemical tests, two forms of pitting on the cladding surface could be observed, including a wide range of pitting lace cover structure and smaller individual pitting. The stainless steel at the composite interface, on the other hand, did not produce any significant pitting craters, indicating that the 304L stainless steel portion of the composite interface was protected during tests. In different marine environments, the corrosion rate of composite interface is greater than that of cladding and substrate, particularly serious in the marine atmospheric environment. Small exposure of the carbon steel part of the composite interface can lead to a serious reduction in the corrosion resistance of the material, so the composite interface should be avoided in actual engineering application.关键词
金属复合材料/不锈钢/碳钢/腐蚀/海洋环境Key words
metal composites/stainless steel/carbon steel/corrosion/marine environment分类
矿业与冶金引用本文复制引用
刘叶诚,郑志斌,龙骏,徐志彪,郑开宏,焦四海,殷福星..海洋环境用热轧304L不锈钢-A36碳钢复合钢板的腐蚀行为研究[J].表面技术,2024,53(14):75-86,12.基金项目
国家重点研发计划(2021YFB3701704):广东省科学院专项资金项目(2022GDASZH-2022010103,2021GDASYL-20210102002) （2021YFB3701704）
第八届中国科协青年人才托举工程(2022QNRC001) （2022QNRC001）
广州市青年科技人才托举项目(QT20220101075)National Key R&D Program of China(2021YFB3701704) （QT20220101075）
GDAS'Project of Science and Technology Development(2022GDASZH-2022010103,2021GDASYL-20210102002) （2022GDASZH-2022010103,2021GDASYL-20210102002）
Young Elite Scientists Sponsorship Program by CAST(2022QNRC001) （2022QNRC001）
Young Talent Support Project of Guangzhou Association for Science and Technology(QT20220101075) （QT20220101075）
