Development of an accelerated test for pitting corrosion of CUSTOM 450 by rDHM

Abstract

A key application of CUSTOM 450 alloy is in the construction of gas turbine compressor blades. The study of pitting corrosion can prevent the failure of many gas turbine compressor blades. In this study, a reflective digital holography microscopy method was employed to investigate the growth of pitting corrosion in depth. To this end, a constant potential of 350 mVSCE in a 3.5 wt.% NaCl solution was applied to the specimen. The generated pits were simulated in three dimensions, and it was indicated that pitting corrosion rate was decreased as time passed. Comparing the obtained experimental data with the data gathered from the real industrial environment surrounding a compressor installation, an accelerated test was proposed. By the proposed accelerated test, it is possible to produce a pit similar to the one that will be initiated and propagated at any time in the future in real conditions.

The effect of microstructural and texture evolutions during thermomechanical treatment on corrosion resistance of 310s austenitic stainless steel

“…According to figure 10 and table 6, it can be seen that there is a tendency to pitting in all specimens since E rp is more negative than E pit for them [75,83]. Meanwhile, positive hysteresis (reverse scan current density is greater than that for the forward scan) is observed in the curves of the specimens, which can be a sign of the susceptibility to pitting corrosion and initiation of pits in the transpassive region [78,80].…”

Surface Characterization Techniques: A Systematic Review of their Principles, Applications, and Perspectives in Corrosion Studies

“…More recent developments with multiscale characterization techniques that assess surface topography changes at the nanoscale have enabled the electrochemical determination of dissolution rates. Particularly, the atomic force microscopy (AFM) [18][19][20][21][22][23][24] and quantitative phase microscopy (QPM) techniques, including vertical scanning interferometry (VSI) [25][26][27][28] and digital holographic microscopy (DHM), [29][30][31][32][33][34][35][36][37][38] have evolved as major microto nanoscale topographic techniques to provide early-stage visualization and quantification of corrosion at the nanoscale. The powerful approach provides different types of information (e.g., characteristics of grains, phases, and surface layers) and insights into the region of interest to gain a comprehensive understanding of the corroding system.…”

“…Journal of The Electrochemical Society, 2022 169 111502 corroded grain boundaries distinguished between IGC and TGC and found that the stainless steel predominantly suffered from IGC corrosion. Pedram et al 31 also developed an accelerated test for pitting corrosion by rDHM and compare it in the actual working condition. From DHM surface topography results, pitting corrosion was observed at 350 mV SCE applied potential, with the pits growing rapidly (250 μm) in the first 10 min while growing just 50 μm in depth at the last 10-min interval.…”