Iron Corrosion in the Radiative Plasma of Moist Air

Abstract

The rate of iron corrosion in a low-temperature plasma of moist air formed under the action of a fast electron beam, depending on the relative air humidity, was measured. It is shown that a beam of fast electrons (radioactive β-radiation) significantly intensifies the corrosion of iron in a plasma-forming gas medium in which oxygen and water vapour are simultaneously present. It has been established that the rate of corrosion under conditions of radioactive irradiation increases sharply when the relative air humidity exceeds 10%. Numerical simulation of the ionic composition of the plasma is carried out taking into account 12 types of positive and 12 types of negative hydrated ions at different intensities of the external ionization source and at different values of relative humidity from 10–6 to 100%. A hypothesis has been put forward about the determining role of cluster hydrated ions, which are formed in the plasma of moist air at atmospheric pressure, in heterogeneous processes of iron oxidation.

Two- and three-body attachment, electron transport and ionisation in water-air mixtures

“…effects, humidity increases the breakdown voltage of moist air discharges, mainly due to the increased electron attachment as compared with dry air [7] and is also one of the most important atmospheric parameters which affect corona discharges [8]. In some cases, water vapour in a plasma can be present as a contaminant, producing undesirable effects such as corrosion [9]. Recently, plasma-activated water [10] has gained much attention due to its importance in agriculture [11], purification, and biomedical applications.…”