Corrosion Studies on Stainless Steel (FE6956) in Hydrochloric Acid Solution

Abstract

The effect of hydrochloric acid concentration on stainless steel (Fe6956) at temperature range 303 -333 ± 1 K has been studied using weight loss, thermometric and electrochemical polarization techniques. The corrosion rate of the stainless steel was found to be dependent on both temperature variation and acid concentration. The potentiostatic study showed that the active passive transition depends strongly on acid concentration while the weight loss measurements revealed that 2 M HCl at temperature 333 K had an appreciable corrosion rate which corresponds to 14.04 × 10 −3 reaction number (RN) got from thermometric monitoring. Arrhenius equation and transition state theory were used to calculate kinetic and thermodynamic parameter such as Ea, ∆H* and ∆S*. Results obtained showed that corrosion reaction of Fe6956 in HCl is spontaneous and there is good agreement between the data got from the techniques employed.

Corrosion of single layer thin film protective coatings on steel substrates for high level waste containers

“…The activated, or transition state, complex can be formed faster and easier for smaller activation energies. The apparent activation energy has been shown to decrease as the concentration of acid in the corrosion solution increases [21]. This further supports that the activation energy represents an energy barrier to corrosion.…”

“…Alternatively, a more appropriate relationship between corrosion rate and temperature may be expressed using the Eyring equation derived from transition state theory (Eq. 9) [20][21][22]:…”

“…Kinetic properties are typically used to describe corrosion in the presence of an inhibitor [17,[19][20][21]. Whereas there is no inhibitor dissolved in the testing solution, the coatings themselves may be considered to function as inhibitors.…”

Corrosion and Oxidation Behavior of a Fe-Al-Mn-C Duplex Alloy

“…The corrosion rate was expressed in millimeters per year. The same conversion table used by Oguike et al [18] was used because it defines the conversion factor to derive the iso-corrosion curves from the quantities directly measurable. In particular, the needed data were easily acquirable as the change in weight, the time, and the surface exposed to the corrosive environment.…”

“…In particular, the needed data were easily acquirable as the change in weight, the time, and the surface exposed to the corrosive environment. Then, the conversion proposed by Oguike et al [18] was used, and this provided the corrosion rate in mm/y, normalized on the density of the material. The procedure used to collect the data is indicated in the standard ISO 17475:sampling of the specimen;measurement of the surfaces and the weight of the sample;immersion for a stated time in the aggressive solution, imposing also the temperature and the concentration of HCl;cleaning and brushing of the specimen to remove all the corrosion products;new measurement of the weight;computation of the change in weight and, consequently, the calculation of the corrosion rate.…”