Corrosion Study of Carbon Steel in Carbonated BUMEA-2EE Nonaqueous Solution

Different effort has been attempted to reduce the equipment corrosion of CO2 absorption using chemical solvents. In this paper, the corrosion of carbon steel in carbonated 2-(butylamino)ethanol (BUMEA)-2-ethoxyethanol (2EE) non-aqueous solution was studied by using a CHI602E electrochemical analyser. The polarization behaviour and corrosion rate of carbon steel in non-aqueous blends of BUMEA-2EE were investigated. The influence of temperature, the mass fraction of BUMEA (wBUMEA) and CO2 loading (α) on the corrosion rate were clarified.

Mode changing, subpulse drifting, and nulling in four component conal pulsar PSR J2321+6024

ABSTRACT In this study, we report on a detailed single pulse polarimetric analysis of the radio emission from the pulsar J2321+6024 (B2319+60) observed with the Giant Metrewave Radio Telescope, over wide frequencies ranging between 300 to 500 MHz and widely separated observing sessions. The pulsar profile shows the presence of four distinct conal components and belongs to a small group of pulsars classified as a conal quadrupole profile type. The single pulse sequence reveals the presence of three distinct emission modes, A, B, and ABN showing subpulse drifting. Besides, there were sequences when the pulsar did not show any drifting behaviour suggesting the possibility of a new emission state, which we have termed as mode C. The evolution of the mode changing behaviour was seen during the different observing sessions with different abundance as well as the average duration of the modes seen on each date. The drifting periodicities were 7.8 ± 0.3 P, 4.3 ± 0.4 P, and 3.1 ± 0.2 P in the modes A, B, and ABN, respectively, and showed large phase variations within the mode profile. The pulsar also showed the presence of orthogonal polarization modes, particularly in the leading and trailing components, which has different characteristics for the stronger and weaker pulses. However, no correlation was found between the emission modes and their polarization behaviour, with the estimated emission heights remaining roughly constant throughout. We have used the Partially Screened Gap model to understand the connection between drifting, mode changing, and nulling.

Data on the Corrosion Resistance and Polarization Behaviour of Lean Austenitic and Ferritic Stainless Steels in Neutral Chloride Media

Stainless steels are extensively applied in diverse industries due to their exceptional corrosion resistance. The corrosion resistance of alloy stainless steels (316L austenitic and 430Ti ferritic stainless steel) was studied in neutral chloride solutions with chloride concentrations of 1%, 2%, 3%, 4%, 5% and 6%. Their general and localized corrosion resistance were compared and discussed in addition to their passivation characteristics. Corrosion rate results obtained showed 430Ti exhibited slightly greater general resistance to chloride attack compared to 316L. Further investigation showed 316L steel exhibited higher resistance to localized corrosion attack to its resilient passive film. 430Ti exhibited cathodic and anodic passivation compared to 316L which only exhibited anodic passivation. Optical microscopic analysis showed the presence of small, superficial corrosion pits on 316L steel compared to 430Ti, which exhibited deep corrosion pits.

Influence of Cl− ions on anodic polarization behaviour of API X80 steel in high potential/current density conditions in Na2SO4 solution

X80 steel gets passivated in high potential/current density conditions in Na2SO4 solution. Low concentration of Cl− ions weakens the passivation. High concentration of Cl− ions totally prevents the passivation.

Effect of Sodium Citrate on Electrochemical Behaviour of Copper in Acid Bath

The initial stages of copper electrodeposition in acid copper sulphate/sodium citrate bath were investigated with varying copper and sodium citrate concentrations. Different electrochemical measurements, including linear sweep voltammetry, cyclic voltammetry, and chronoamperometry were introduced to the study. The Scharifker-Hills model was introduced to identify the nucleation model with analysing current transients. It was observed that the increase of copper ions inhibited the cathodic polarization behaviour for the reduction of ions. On the contrary, sodium citrate promoted the cathodic polarization behaviour. The chronoamperometry results indicated that without the sodium citrate, the nucleation process corresponded to instantaneous nucleation and three-dimensional diffusion limited growth, although obvious deviations were observed. While the addition of sodium citrate changed the deviations and caused that the initial deposition kinetics followed well with the mechanism of instantaneous nucleation.