Detection of under deposit corrosion in a CO2 environment by using electrochemical noise and recurrence quantification analysis

Evaluating the Flow Accelerated Corrosion and Erosion–Corrosion Behavior of a Pipeline Grade Carbon Steel (AISI 1030) for Sustainable Operations

Erosion–corrosion behavior of pipeline grade carbon steel alloy (AISI 1030) was investigated using a state-of-the-art jet impingement flow loop. Different impingement velocities (3 to 12 m/s) and angles (15°, 30°, 45°, 60°, and 90°) were employed (with/without sand particles) to study the degradation behavior of this pipeline grade steel in 0.2 M NaCl solution at room temperature. Experiments were conducted for a duration of 24 h at room temperature. The maximum erosion–corrosion (EC) rate was observed at an impingement angle of 45° at all velocities (3 to 12 m/s), as both the shear and normal impact stresses were of the same order of magnitude at this angle. At lower impingement angles, the effect of shear stress was more dominant and vice versa at higher impingement angles. The synergistic affect was found to be maximum at 45° due to enhancement of erosion by corrosion and/or corrosion by erosion. Ploughing, deep craters, raised lips, dimples, micro-forging/plastic deformation, and extrusion were the dominant erosion–corrosion mechanisms as observed by Field Emission Scanning Electron Microscopy (FE-SEM). The maximum corrosion wear scar depth was found to be 57 µm (average) at an impingement angle of 45°, as measured using an optical profilometer. The obtained results are very significant and can be used in process parameter optimizations to enhance infrastructure reliability. These results will also be the part of in-house database to develop a comprehensive erosion and erosion–corrosion model for erosion–corrosion prediction of different materials under various operational conditions.

Comparative Study on Flow-Accelerated Corrosion and Erosion-Corrosion at a 90° Carbon Steel Bend

Electrochemical measurements and surface analysis are performed to comparatively study flow-accelerated corrosion (FAC) and erosion–corrosion (E-C) behavior at a 90° carbon steel bend. The corrosion rates are higher under FAC conditions than those under E-C conditions. For FAC, the corrosion is more serious at the inside wall. However, corrosion is exacerbated at the outside wall under E-C conditions. No erosion scratches are observed under FAC conditions and at the inside wall under E-C conditions, while remarkable erosion scratches appear at the outside wall under E-C conditions. The dominant hydrodynamics affecting FAC and E-C are remarkably different.