Session: CT-01-02 Design and Analysis of Bolted Flange Joints-2

Paper Number: 124104

124104 - Effect of Temperature on the Crevice Corrosion Propagation on Flange Faces 

The corrosion of the flange face poses a significant risk to the structural integrity of bolted flanged connections and can lead to severe leakage problems. It has been observed on multiple occasions that bolted flanged joints experience premature failure due to crevice corrosion on the flange faces—where the gasket is positioned, and these areas are not accessible and visible. Crevice corrosion occurs due to the breakdown of the passive layer in an occluded area, specifically at the flange and gasket interface, greatly increasing the corrosion rate of the flange compared to general corrosion. The breakdown of the passive layer is a challenging phenomenon, occurring on a small scale and within a short period, making it difficult to detect through regular inspection methods. The propagation of crevice corrosion can be significantly influenced by temperature. Elevated temperatures often accelerate the corrosion process, leading to a higher rate of material degradation. Given that crevice geometry is one of the most influential factors in crevice corrosion, the specially designed COrrosion Quantification Test (COQT) fixture, as introduced in previous studies by the authors, is utilized in this research, allowing the application of various electrochemical techniques to assess flange corrosion in controlled testing environments. This research aims to measure and compare the mass loss rate of the flange at different temperatures: 22°C, 30°C, 40°C, 50°C, 60°C, 70°C, and 80°C. The chemical composition of the flange specimens complies with ASTM A182 F321 stainless steel, while virgin PTFE is used for the gasket material. Electrochemical examinations are conducted using a 3.5% NaCl solution. Confocal laser microscopy and scanning electron microscopy (SEM) are utilized to observe the surface morphology and to measure crevice volumes induced by corrosion. By analyzing the results of electrochemical assessments and microscopic characterizations, the rate of material loss in the flange due to crevice corrosion at different temperature settings can be quantified.

Presenting Author: Soroosh Hakimian École de technologie supérieure

Presenting Author Biography: Soroosh Hakimian is a PhD candidate in the Department of Mechanical Engineering at École de technologie supérieure (ÉTS) university. His studies focus on the corrosion of bolted flanged joints in pressure vessels and piping, and the application of machine learning techniques in the field of corrosion for predictive maintenance in the oil and gas industry.

Authors:

Soroosh Hakimian École de technologie supérieure
Hakim A. Bouzid École de technologie supérieure
Lucas A. Hof École de technologie supérieure