Corrosion behavior and mechanism of 3Cr steel in CO2 environment with various Ca2+ concentration. (15th May 2018)

• Record Type: Journal Article
• Authors: Wang, Bei; Xu, Lining; Liu, Guozhang; Lu, Minxu
• Is Part Of: Corrosion science. Volume 136(2018)
• Page Start: 210
• Page End: 220
• Publication Date: 2018-05-15
• Subjects: Low alloy steel -- Weight loss -- Polarization -- Acid corrosion -- Passivity; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.03.013
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The corrosion rate of 3Cr steel in a CO2 environment decreased as the Ca 2+ concentration in the solution increased. The composition and grain surface of corrosion scale have an obvious dependence on Ca 2+ concentration in the solution. The addition of Ca 2+ to the solution can decrease the anodic reaction of 3Cr steel. The addition of Ca 2+ to the solution can strengthen the pseudopassivation of 3Cr steel. Abstract: The effect of Ca 2+ on the corrosion behavior of 3Cr steel was investigated using immersion tests and electrochemical measurements. The results demonstrated that with an increase in Ca 2+ concentration in the solution, the corrosion rate of 3Cr steel decreased and the Ca 2+ content in the corrosion scale increased. Ca is involved in the formation of both the inner and outer corrosion scales of 3Cr steel. Polarization curves revealed that Ca 2+ could enhance the pseudopassivation of 3Cr steel. EIS results demonstrated that Ca 2+ can decrease the porosity of corrosion films. Additionally, Ca 2+ could accelerate the precipitation of FeCO3 (Cax Fe1−x CO3 ) by reducing its solubility and saturation degree.