Temperature effect on the corrosion and passivation characterization of Ni82.3Cr7Fe3Si4.5B3.2 alloy in acidic media

Effect of acid proticity on the thermodynamic parameters of charge transfer resistance in corrosion and passivation of nickel based glass alloy

“…As a continuation of our previous works 1 , 22 and, based on the above considerations, we suggest some novel empirical models for thermodynamic parameters in the present work. Therefore, we will introduce a new concept of current quantities after considering the dependence with temperature of the Arrhenius and thermodynamic parameters.…”

“…The activation energy ( Ea ) can be determined from Arrhenius plot that often used to analyze the effect of temperature on the rates of chemical reactions where the reactants molecules colliding probability becomes higher and the reaction proceeds faster at higher temperatures. In our study Ea of the corrosion process of glassy alloy in 3.0 mol/L solutions of the studied acids was obtained from the assumed linear variation of the corrosion reaction rate assigned as the reciprocal of the charge transfer resistance, 1/ R ct , with temperature 1 , 22 .…”

“…The high corrosion resistance features that often extend an improved corrosion resistance of metallic glasses which chemically afford a smooth contacting metallic surface with minimal defects and free of voids, dislocations and/or atomic terraces, so they have no crystallographic dislocations, crystal imperfections, distortions, grain boundaries or secondary phase elements 1 – 3 . Passivation is the process of making a material “non-reactive” in relation to another material 4 , 5 .…”

“…In our previous study, a systematic study of the corrosion and passivation behavior of the Ni 82.3 Cr 7 Fe 3 Si 4.5 B 3.2 ( wt %) in 3.0 mol/L aqueous solutions of HCl, H 2 SO 4 , and H 3 PO 4 acids solutions at temperatures range (20–80) was carried. The passive film on Ni 82.3 Cr 7 Fe 3 Si 4.5 B 3.2 ( wt %) glassy alloy surfaces was a uniform and stable chromium oxy-hydroxide [CrO x (OH) 3−2 x ·nH 2 O], which is a few atoms thick 1 . In recent research 22 we have extended the Arrhenius-type expression by one term in 1/ T 2 and collected some physical meaning to the new related coefficients for which it is found that they depend closely on the number of acid hydrogen atoms in the polyacid for the corrosion and passivation of the nickel based metallic glass alloy of the composition Ni 82.3 Cr 7 Fe 3 Si 4.5 B 3.2 .…”

Effects of Cr content on the corrosion behaviour of porous Ni–Cr–Mo–Cu alloys

“…Impedance and polarisation curves of these porous Ni–Cr–Mo–Cu alloys indicated that the corrosion process was accompanied by a charge transfer over potential, i.e. it is an activation type [36]. The apparent activation energy ( E a ) of the corrosion process of porous alloy in 10 wt-% H 2 SO 4 solution was obtained from the linear variation of the corrosion reaction rate, assigned as the exchange current density ( j 0 ) with temperature, which obeyed the familiar Arrhenius equation as follows.…”