Electrochemical Properties of Super Austenite Stainless Steel with Temperature in a Green Death Solution

Abstract

In this investigation, potentiodynamic polarization experiments were conducted on UNS S31603 and UNS N08367 in a modified green death solution, which simulates the environment of a desulfurization device (scrubber), using temperature as a variable. A Tafel analysis showed that the corrosion current density of UNS S31603 at the highest temperature (90 °C) was approximately 4.5 times higher than that of UNS N83067. A surface analysis using a scanning electron microscope revealed that pitting and intergranular corrosion occurred simultaneously in UNS S31603, whereas UNS N83067 exhibited a stronger tendency toward intergranular corrosion. After electrochemical experiments, the corrosion rates according to maximum damage depth were compared with the corrosion rates according to corrosion current density; the relationships between the two values were expressed as α values. The α values of UNS N08367 were higher than those of UNS S31603, indicating that the local damage rate of UNS N08367 was higher.

Optimization of Electropolishing Process Using Taguchi Robust Design for UNS N08367 in a Mixed Solution of Sulfuric Acid and Phosphoric Acid

“…Therefore, stable values were maintained in all electropolishing conditions after 4 min, indicating that the electrochemical reaction proceeded stably. Stainless steel containing Mo and Cr forms a bipolar passive oxide film [34]. The two-phase membrane consists of a cation-selective layer (CrO 4 2− , MoO 4 2− ) and an anion-selective layer.…”

“…A depth histogram is a graph showing the distribution (y-axis) from the shallowest to the greatest depth (x-axis). It can be used to infer the state of a metal surface from the mean and dispersion, so is useful when calculating the optimal conditions for electropolishing [35]. Since the depth histogram in this experiment followed a normal distribution, information on surface planarization was obtained using the mean and dispersion.…”

Electrochemical characteristics and damage mechanism in scrubber washing water of UNS N08367 with plasma ion nitriding and electropolishing

“…The area in contact with the holder packing is a passivation film formed in the air, and the area in contact with the washing water presents a structure that is bipolar with the electrochemical characteristics of the passivation film. The bipolar structure is composed of molybdate ions (MoO4 2-) as a cation-selective layer and chromium hydroxide (Cr(OH)3) as an anion-selective layer [43]. The external cation selection layer suppresses the permeation of aggressive ions in metal.…”

Recent advances in the construction and application of stretchable PEDOT smart electronic membranes

“…150 By forming micron or even nano-patterned structures, the surface morphology, optical properties, and mechanical properties can be adjusted, and rigid materials can be endowed with stretchability. 151,152 As shown in Fig. 7a-i and ii, Lo et al 153 deposited PEDOT: PSS and polyethylene oxide (PEO) composite inks to form a patterned structure (about 400 mm in line width) on a PDMS substrate by inkjet printing.…”