Corrosion Inhibition of Carbon Steel in hydrochloric acid medium using Gliclazide drug

  • Tab. 10: EFM kinetic variables calculation from CS that submersion in 1 M HCl without and with various doses of Gliclazide at 25 oC
    Tab. 10: EFM kinetic variables calculation from CS that submersion in 1 M HCl without and with various doses of Gliclazide at 25 oC
The role of Gliclazide as corrosion drugs for CS in 1 M HCl have been studied by using weight loss (WL), Hydrogen evaluation (HE), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and Electrochemical frequency modulation (EFM) techniques. Weight loss (WL) studied at various temperatures between (25 – 45oC) but Hydrogen evaluation (HE), Open circuit potential (EOCP) and all electrochemical studied at 25oC and seen that the gliclazide studied are mixed type drug. The effect of temperature on corrosion inhibition, the activation and the thermodynamic of adsorption parameters were determinate. Electrochemical impedance was utilizing to examine the inhibition of corrosion and the mechanism. The existence of the Gliclazide in the solution rise the charge transfer resistance and reducing the capacitance of the double layer. The adsorption of the Gliclazide on the surface of CS was found to obey with Langmuir adsorption isotherm and discussed the thermodynamic parameters (ΔGo, ΔHo and ΔSo) that were determinate. The morphology of inhibition of Gliclazide on CS surface was analyzed by scanning electron microscope (SEM) technology, energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM), all examine techniques illustrate the formation of thin film from Gliclazide inhibitor adsorbed on the metal surface.It was found the adsorption process is spontaneous and increases, with increasing of inhibition efficiency.


    

New generation of acid Zn-Ni electrolyte for barrel application (Part 2)

  • Fig. 22: M10 bolts coated with Zinni® 220 and passivated with Tridur DB, heat treated (hydrogen de-embrittlement) at 210 °C for 4 hours after passivation; samples before NSS test (a) and after 504 h in NSS chamber (b); test according to ASTM B-117
    Fig. 22: M10 bolts coated with Zinni® 220 and passivated with Tridur DB, heat treated (hydrogen de-embrittlement) at 210 °C for 4 hours after passivation; samples before NSS test (a) and after 504 h in NSS chamber (b); test according to ASTM B-117

The demand for Zinc Nickel coatings continuously increases in the automotive industry. Especially interesting are zinc nickel alloys with a nickel incorporation of 12–16 %, due to their high corrosion protection as well as superior wear and heat resistance as compared to pure zinc and other zinc alloy coatings.
Despite many advantages of acid Zn-Ni electrolytes there are still some areas of application, like barrel plating or plating of complex-shaped parts, believed to be reserved for alkaline processes. In this paper zinc nickel coatings deposited from ammonium and boric acid-free acid zinc nickel electrolytes, with improved throwing power for rack and barrel applications are investigated. Their corrosion resistance, ductility and hardness will be presented. Moreover, their texture and morphology will be investigated using SEM, XRD and FIB methods. In the end thickness distribution and Ni-incorporation will be presented and compared to alkaline systems.


    

Electrochemical Investigations for the Corrosion Control of Aluminum using an Eco friendly Natural Inhibitor

Fig. 2: Potentiodynamic polarization plots for the corrosion of aluminum containing different concentrations of CLE in H2SO4 (pH=3) at 30 oC

The inhibitive effect of Curry leaves extract (CLE) on the corrosion behavior of aluminum in sulfuric acid (pH = 3) was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques in the temperature range of 30 °C to 50 °C. The study was done by varying the concentrations of inhibitor from 0.05 g L−1 to 0.4 g L−1. The surface morphology was studied using scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). Inhibition efficiency was found to increase with increase in inhibitor concentration and decrease with increase in temperature. CLE acted as an anodic type inhibitor at lower concentrations of inhibitor and behaved as a mixed type at higher concentrations of inhibitor and underwent both physisorption and chemisorption on the surface of the metal and followed the Langmuir adsorption isotherm.