模拟海洋与工业大气环境下结构钢腐蚀行为

Corrosion behavior of structural steel in simulated marine and industrial atmosphere environment

分别采用室内盐雾试验模拟海洋大气环境、周浸试验模拟工业大气环境,研究碳素结构钢在两种不同模拟环境下的腐蚀行为.通过SEM扫描电镜分析了碳素结构钢在两种不同环境下的腐蚀微观形貌差异,采用三维非接触表面形貌仪获得腐蚀试样点蚀深度分布模型和点蚀深度变异系数.结果表明:两种不同大气环境下碳素结构钢腐蚀形貌有明显差异;平均腐蚀深度与时间呈幂函数关系;点蚀深度近似服从正态分布,点蚀深度变异系数随腐蚀时间的增长有减小趋势,可作为碳素结构钢腐蚀特征评价指标之一.进一步采用灰色系统理论对碳素结构钢室内外腐蚀相关性进行分析,验证了室内模拟加速腐蚀试验的合理性,并建立了室内外腐蚀相关性预测模型,可用于碳素结构钢在海洋大气和工业大气环境下腐蚀程度的预测.

The corrosion behavior of carbon structural steel in two different simulated environments were studied by simulating marine atmosphere with salt spray test and industrial atmosphere with alternate immersion test.The corrosion micro morphology of carbon structural steel in two different environments was analyzed by SEM.The pitting depth distribution model and variation coefficient of pitting depth were obtained by three-dimensional non-contact surface morphology analyzer.The results show that the corrosion morphology of carbon structural steel is obviously different in two different atmospheric environments.The relationship between average corrosion depth and time is a power function.The pitting depth approximately follows the normal distribution,and the variation coefficient of pitting depth decreases with the increase of corrosion time,which can be used as one of the evaluation indexes of carbon structural steel corrosion characteristics.Then,the gray system theory was used to analyze the correlation between indoor and outdoor corrosion of carbon structural steel,which verified the rationality of indoor simulated accelerated corrosion test.The correlation prediction models of indoor and outdoor corrosion were established,which can be used to predict the corrosion depth of carbon structural steel in marine atmosphere and industrial atmosphere.