超级13Cr不锈钢在海洋油气田环境中腐蚀行为灰关联分析

Gray Relationship Analysis on Corrosion Behavior of Super 13Cr Stainless Steel in Environments of Marine Oil and Gas Field

采用动电位极化曲线测量了超级13Cr不锈钢在不同海洋油气田环境因素下的腐蚀速率;利用灰关联法分析了Cl-浓度、S2-浓度、pH值和温度与超级13Cr不锈钢腐蚀行为之间的关系。结果表明:海洋油气田环境中,影响超级13Cr不锈钢腐蚀行为的主要环境因素按关联度大小依次为:Cl^-浓度(0.8223)>温度(0.7704)>pH值(0.7646)>S2-浓度(0.7595)。通过改进层次分析法对海洋环境中环境因素对超级13Cr腐蚀速率进行权重分析,权重从大到小依次为:Cl^-浓度(0.3905)>温度(0.2761)>pH值(0.1953)>S2-浓度(0.1381)。海洋油气田环境中高浓度Cl^-和高温环境是造成超级13Cr不锈钢腐蚀失效的主要原因。

The corrosion rate of super 13Cr stainless steel was measured by potentiodynamic polar- ization curves in different environments of marine oil and gas field. Then the relationship between the cor- rosion behavior of super 13Cr stainless steel with the concentration of CI-, concentration of S2-, pH value and temperature was evaluated by means of grey relationship analysis. Results showed that the grey cor- relation degree of corrosion factors in the marine oil and gas environments could be ranked with a de- scending sequence as follows： concentration of Cl- （0.8223）〉temperature （0.7704）〉pH value （0.7646）〉 concentration of S2- （0.7595）. The weight of the effect of each corrosion factor on the corrosion rate of su- per 13Cr stainless steel was analyzed by hierarchy process, which then could be ranked with a descend- ing sequence as follows： concentration of Cl- （0.3905）〉temperature （0.2761）〉pH value （0.1953）〉con- centration of S2- （0.1381）. The main factors of the marine oil and gas environment, which caused the cor- rosion failure of super 13Cr stainless steel, were the high concentration of Cl- and high temperature.