利用形貌分析、腐蚀失重、X射线衍射仪(XRD)、电化学方法开展对CCSA和Q235B两种船用钢板材料在长江淡水环境中不同区域(大气区、水线区、水下区)暴露0.5、1、2、3、4和7a腐蚀行为的研究.结果表明,两种碳钢在长江淡水环境发生明显腐蚀,且腐蚀形貌十分相似,腐蚀发展均遵循幂函数规律;在大气区、水线区和水下区,第7 a CCSA的腐蚀率分别为8、77和40 μm·a-1,Q235B的腐蚀率分别为9、80和41 μm·a-1,在水线区腐蚀最为严重.腐蚀产物成分中除泥沙外,主要包含α-FeOOH、γ-FeOOH、Fe2O3和Fe3O4/γ-Fe2O3.综合电化学分析结果,CCSA较Q235B具有更好的耐蚀性,长江淡水环境不同区域对碳钢腐蚀快慢程度由大到小排序为:水线区＞水下区＞大气区.
Corrosion Behavior of Two Steels CCSA and Q235B in Changjiang Freshwater Surroundings
There is limited studies available on the corrosion of carbon steel in freshwater surround-ings.Herewith,plates of two ship steels CCSA and Q235B steel were exposed to different sites such as the atmosphere,waterline,and underwater in freshwater surroundings of the Changjiang River(Yangtze River)for 0.5,1,2,3,4,and 7 a,then there corrosion behavior was assessed by means of morphology analysis,mass-loss measurement,XRD,and electrochemical techniques.Results show that the two car-bon steels suffered from significant corrosion in the freshwater surroundings of the Changjiang River,ex-hibiting nearly the identical corrosion morphology.Their corrosion processes follow a power function law.After 7 years,the corrosion rates of CCSA were found to be 8,77 and 40 μm·a-1 in the atmosphere,wa-terline,and underwater,respectively,while the corrosion rates of Q235B were 9,80,and 41 μm·a-1 in the same conditions.Among others,the corrosion on the waterline was the highest.The composition of the corrosion product of the two carbon steels was similar,primarily including SiO2,α-FeOOH,γ-FeOOH,Fe2O3 and Fe3O4/γ-Fe2O3.Based on the comprehensive electrochemical analysis results,CCSA demon-strated better corrosion resistance than Q235B.Regarding to the test results in various test sites of fresh-water surroundings of the Changjiang River,the corrosion rate of the carbon steels may be ranked in de-scending order as follows:waterline＞underwater＞atmospheric.
CCSAQ235Bfreshwater environment of Changjiangcorrosion
万方数据
维普
