Modeling of corrosive atmospheres for evaluation of the efficiency of volatile inhibitors

Abstract

A method of modeling aggressive atmospheres used for different tests in corrosive environments close as possible to actual full-scale conditions is proposed. The method provides simulation of air atmospheres containing gaseous corrosion stimulants (CS) as microcomponents of air. The content of SCs in such atmospheres (both separately and together) can be set and maintained at an unchanged level within a wide range for as long as desired. The method is based on Henry’s equation characterizing concentration of the gas dissolved in a liquid phase as a function of the gas partial pressure in the equilibrium gas medium with allowance for the solubility of the corrosion stimulants in water in conditions under consideration. The procedure is easy to use and does not require long special training. Samples of corrosion stimulants NH3, CO2, and H2S are considered. Experimental results characterizing the corrosion rate of St3 carbon steel and copper with one or several CS simultaneously present in air atmosphere, as well as data on the efficiency of volatile inhibitors of «IFHAN» series under similar conditions are presented.

A Review of Recent Advances in the Inhibition of Sweet Corrosion

“…Several studies reported in the past decade on the corrosion inhibition of different types of steel in a CO 2 /H 2 S coexisting environment, [66–67,71a‐c,72,76,115,131d,140] as presented in Table 2. The solutions employed in these studies, consisting of either NaCl solutions [71–72,76,115,131d,140a] or brine and simulated oilfield waters, [66–67,140b,c] were usually saturated with both CO 2 and H 2 S. In a few of these studies, the authors also reported on the influence of either the pressure/concentration of CO 2 and H 2 S or their ratio on the corrosion inhibition of the respective CIs [66,72,76,115,140a] . In addition, Qiu et al [140b] .…”

“…Table 2 shows that the compounds used as CIs in a CO 2 /H 2 S coexisting environment were mostly imidazoline derivatives, [66,71b,72,115,140a,141] quaternary ammonium salts, [66,67b,71b,72,140b] and Gemini surfactants [67a,b] . A few CIs employed in this environment were obtained as a combination of different organic compounds, including azole compounds, polyamines, and organic acids [76] . Moreover, Rivera‐Grau et al [131d] .…”

“…The authors reported that the corrosion inhibition effectiveness of bis(2‐ehylhexyl) phosphate decreased with an increase in the concentration of oxygen. Vigdorovich et al [76] . evaluated the corrosion inhibition effectiveness of three volatile inhibitors of the IFKhAN series in the corrosion of St3 steel immersed in 0.1 M NaCl, in a CO 2 /NH 3 coexisting environment (i. e. 0.2–0.6 vol.% CO 2 and 10–30 mg/m 3 H 2 S) as well.…”

Assessment of the protective effectiveness of a volatile inhibitor in atmospheric corrosion of steel under conditions of increased concentrations of carbon dioxide, ammonia and hydrogen sulfide by electrochemical methods

“…This resulted in the hydrolysis of + 4 NH and S 2ions to form NH 4 OH and H 2 S, which are stable in the surface phase film, as noted above. To compare the results obtained by electrochemical and weight tests, the latter were carried out in sealed desiccators with a volume of 7 L, where the specified concentration of CSs was created in the gas phase according to the method proposed by the authors of the article [7]. The value of 100% relative humidity in the desiccators was achieved by the presence in them of an additional small capacity with distilled water.…”

Study of Efficiency of Compositions Based on Cortec Vpci-368 and Cortec Vpci-369 for Anti-Corrosion Protection of Agricultural Equipment

“…Введение. Для противокоррозионной защиты сельскохозяйственной техники традиционно используют консервационные материалы на масляной основе, как одни из самых доступных [1][2][3][4][5][6][7][8] и водно-восковые составы [9][10][11]. В ФГБНУ ВНИИТиН в последние годы ведутся разработки по исследованию возможности использования летучих ингибиторов коррозии (ЛИК) для этих целей [12][13][14][15][16][17].…”