The study on the influence of aluminum on the CO₂ corrosion resistance of 3%Cr steel

Abstract

Purpose

This study aims to report the CO₂ corrosion performance of 3Cr steel and 3Cr2Al steel and reveal the role of aluminum in mitigating corrosion of low-Cr steel.

Design/methodology/approach

Aluminum was added to 3Cr steel to prepare a new type of 3Cr2Al steel, and the effect of aluminum on the corrosion resistance of pipeline steel was studied using morphology observation and composition analysis, weight loss tests and electrochemical test.

Findings

In the CO₂/O₂ coexistence environment, the average corrosion rate of the 3Cr2Al steel was obviously lower than that of the 3Cr steel. The addition of aluminum expanded the range of prepassivation, and the dynamic potential polarization curve of 3Cr2Al steel showed duplex prepassivation phenomena. 3Cr steel underwent severe local corrosion, and 3Cr2Al steel underwent uniform corrosion. The addition of aluminum contributed to the formation of a dense corrosion product layer and greatly reduced the localized corrosion sensitivity.

Originality/value

The studies on CO₂ corrosion of aluminum containing low-Cr steel are quite rare. This study clarifies the role of aluminum by comparing the corrosion behavior of 3Cr2Al and 3Cr steel. The effect of aluminum on the growth of corrosion product film was discussed, and the duplex prepassivation phenomena of Cr and Al were revealed.

Citation

Gao, Z., Liu, Y., Wang, C., Yang, H., Xu, L. and Qiao, L. (2022), "The study on the influence of aluminum on the CO₂ corrosion resistance of 3%Cr steel", Anti-Corrosion Methods and Materials, Vol. 69 No. 2, pp. 177-182. https://doi.org/10.1108/ACMM-11-2021-2565