论文部分内容阅读
通过浸泡实验研究了不同浸泡时间下X80管线钢在库尔勒土壤模拟溶液中形成的腐蚀产物膜的变化规律,通过SEM观察了腐蚀产物膜的微观形貌,通过XRD分析了腐蚀产物膜的物相组成;借助循环极化曲线和电化学阻抗等方法,研究了腐蚀产物膜对X80管线钢点蚀行为的影响规律和机理。结果表明:随着浸泡时间的延长,X80管线钢在库尔勒土壤模拟溶液中形成的腐蚀产物膜逐渐增厚,致密性逐渐提高。当浸泡时间达到168 h以后,腐蚀产物膜明显地分为了内外两层。表面存在的腐蚀产物膜可以阻碍或抑制X80管线钢的点蚀行为,这主要是因为表面腐蚀产物膜减少了蚀孔萌生的几率,增大了蚀孔长大的阻力。
The corrosion behavior of X80 pipeline steel in simulated solution of Korla soil was studied under different immersion time by immersion time. The morphology of corrosion film was observed by SEM. The phase composition of corrosion film was analyzed by XRD. The influence law and mechanism of corrosion product film on pitting corrosion of X80 pipeline steel were studied by means of cyclic polarization curve and electrochemical impedance. The results show that the corrosion products formed on the X80 pipeline steel in Korla soil simulated solution gradually thicken with the soaking time increasing, and the compactness gradually increases. When the soaking time reaches 168 h, the corrosion product membrane is obviously divided into two layers inside and outside. The corrosion products existing on the surface can hinder or inhibit the pitting corrosion of X80 pipeline steel. This is mainly because the surface corrosion product film reduces the probability of pitting initiation and increases the resistance of growth of pitting.