Abstract
In the present work, a ca. 40 µm residual cementite layer was developed on a 1018 carbon steel surface in a 2-day pre-corrosion step. After adding the imidazolinium-type inhibitor, its inhibition efficiency (IE) significantly decreased in the presence of the cementite layer when compared with what was observed for the bare steel surface. With a high enough concentration of inhibitor, the minimum inhibited corrosion rate (CR) obtained is still higher than that for the bare steel surface. The anodic reaction was retarded to the same extent as that on the bare surface. Retardation of the cathodic reaction was evaluated after normalizing cathodic reaction area, relating to the area increase due to residual cementite. After area normalization, retardation of the cathodic reaction was essentially the same as for the bare surface. This implied that the larger minimum inhibited CR of the specimen with residual cementite was only because of the increased cathodic reaction area.
Keywords:
corrosion product, cementite, corrosion inhibitor, inhibition efficiency, cathodic reaction, area normalization
Status
G
Department
Chemical and Biomolecular Engineering
College
Russ College of Engineering and Technology
Campus
Athens
Faculty Mentor
Singer, Marc
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Quantitative Investigation of Residual Cementite on the Performance of an Imidazolinium-type Corrosion Inhibitor with Mild Steel
In the present work, a ca. 40 µm residual cementite layer was developed on a 1018 carbon steel surface in a 2-day pre-corrosion step. After adding the imidazolinium-type inhibitor, its inhibition efficiency (IE) significantly decreased in the presence of the cementite layer when compared with what was observed for the bare steel surface. With a high enough concentration of inhibitor, the minimum inhibited corrosion rate (CR) obtained is still higher than that for the bare steel surface. The anodic reaction was retarded to the same extent as that on the bare surface. Retardation of the cathodic reaction was evaluated after normalizing cathodic reaction area, relating to the area increase due to residual cementite. After area normalization, retardation of the cathodic reaction was essentially the same as for the bare surface. This implied that the larger minimum inhibited CR of the specimen with residual cementite was only because of the increased cathodic reaction area.