摘要
采用旋转圆盘冲刷装置测试了P110钢在多因素耦合条件下的冲刷腐蚀速率,装置配有电化学测试仪,通过失重法和电化学测试相结合的方式比较砂粒尺寸、含砂量、液体流速等对流砂条件下P110钢冲刷腐蚀情况的影响,利用扫描电子显微镜观察冲刷腐蚀后的形貌。结果表明:相同介质中,液体流速、砂粒尺寸与P110钢表面受力学作用强度呈正比关系;由于Cl-对钢材表面钝化膜的破坏作用,NaCl浓度值越大腐蚀失重速率越高;冲刷过程中,砂粒的表面粗糙度降低,而后因破碎作用而恢复,同一冲刷条件下,冲刷腐蚀速率随时间先降低,后升高;含砂量对冲刷腐蚀速率的影响存在一个临界值——3%(质量分数),超过临界值时随含砂量先增大后减小,腐蚀速率降低是大量固体颗粒沉积导致的"屏蔽效应"所引起的。
A rotating disk flush equipment with an electrochemical testing station was used to test the erosion -corrosion rate ofthe Pll0 steel under a multiple- factor coupling conditions. The impacts of different parameters such as particle size, sand content and flow rate on the erosion - corrosion rate of the P110 steel were compared by weight loss and electrochemical tests. The corrosion morphology was observed by scanning electron microscopy. The results show that the impacting force on surface of PllO steel is positively related to the liquid flow rate and grain size of sands in the same electrolyte; The rising NaC1 concentration will aggravate the erosion - corrosion because of the destruction of C1- for passive film. The erosion will reduce the roughness of sand surface, which will resume after the sands are broken. The erosion - corrosion rates increase first and then decrease with time. The impact of sand content on erosion- corrosion rate has a threshold of 3% （wt）. When the threshold is exceeded, the erosion - corrosion rate increases first and then decreases because of the “ shielding effect” induced by the deposition of a larze amount of solid particles.
出处
《石油化工腐蚀与防护》
CAS
2014年第1期11-14,26,共5页
Corrosion & Protection In Petrochemical Industry
关键词
P110钢
冲刷腐蚀
电化学腐蚀
失重法
PllO steel, erosion - corrosion, electrochemical corrosion, weight - loss method
