均匀设计法研究环境因素对X120管线钢点蚀敏感性交互影响

Interactive influence of environmental factors on the pitting susceptibility of X120 pipeline steel studied by a uniform design method

以Cl浓度、pH值和温度为三因素,通过均匀设计试验方法,采用动电位扫描技术研究了这三个环境因素对X120管线钢在HCO3-+Cl介质中点蚀电化学行为的交互影响.结果表明:Cl浓度、pH值和温度三因素对X120管线钢在HCO3-+Cl溶液中的腐蚀和钝化行为影响都较大,对其点蚀敏感性影响依次为Cl浓度>pH值>温度,且Cl-浓度与温度间存在交互作用,该交互作用对X120管线钢点蚀敏感性的影响程度介于Cl浓度和pH值之间;在Cl浓度为0mol·L-1、pH8.5、温度0℃的HCO3-+Cl溶液中,X120管线钢的点蚀敏感性最小.

A uniform design experimental method was employed to discuss the interactive influence of Cl^- concentration, pH values and temperature on the pitting susceptibility of X120 pipeline steel in HCO3^- ＋ Cl^- solutions by a potentiodynamic scan technique. The experimental results indicate that Cl^- concentration, pH values and temperature have great effect on the corrosion and passive behavior of X120 pipeline steel in HCO3^- ＋ Cl^- solutions, and the influence order is as follows： Cl^- concentration has the greatest impact, then the combined action of Cl^- concentration and temperature, the third one is pH values, and temperature has the smallest impact. X120 pipeline steel has the least pitting susceptibility in the HCO3^- ＋ Cl^- solution whose C1 concentration is 0 mol· L^-1 , pH value is 8.5 and temperature is 0℃.