Comparison of corrosion protection of normal and galvanised steel coated by cathodic electrocoatings using EIS and salt spray tests

Abstract

Cathodic electrocoatings were applied onto phosphated normal and galvanised steel substrates with average dry film thicknesses of 20 and 12 mm. To evaluate the anticorrosion properties of the coatings, electrochemical impedance spectroscopy and salt spray tests were carried out on the samples. The results showed that, by increasing the curing temperature, the protective properties of electrocoated galvanised steel are improved to a higher extent compared to normal steel panels. This was indicated by a pore resistance of two orders of magnitude higher in the case of galvanised steel panels. At lower curing temperatures, the corrosion resistance of electrocoated normal steel panels is better than that of the galvanised steel, indicated by a two orders of magnitude higher pore resistance value. On the other side, the salt spray test could not recognise the difference between protective properties of different coating films on galvanised steel suitably, and this is one of the notable disadvantages of this test.

Corrosion resistance of surface-conditioned 301 and 304 stainless steels by salt spray test

“…If properly deposited in right proportions, coatings have the tendency of improving the fracture and corrosion resistance of materials [25][26]. In addition, Esfahani et al [17] reported an increase in corrosion resistance of normal steel panel as compared with galvanized steel. In another study [16], the corrosion resistance of both AZ91D and AM50 alloys decreased with an increase in chloride concentration.…”

“…It is a promising method for identifying the time when the first sign of corrosion is evident after subjecting the material to a long corrosion test. In the past, salt spray test method has been successfully used to evaluate the corrosion behaviour of different material systems including stainless steel [5,[8][9], Al 2 O 3 -ZrO 2 [10], Al 2 O 3 [11][12], ZrO 2 [12][13], alumina coating [14][15], Mg-Al alloy [16], and galvanized steel [17][18]. Stainless steel types 301 and 304 are presently attracting considerable attention due to their good mechanical and corrosion properties and they find applications in most manufacturing and production industries.…”

Protective Material of the Security Mechanism Friction Surface on the Ship Lift

“…Salt spray test can effectively simulate the corrosion of the workpiece under actual conditions [7,8]. One sample was not coated with protective material and the other was coated with protective material.we put them into salt spray test, to compare the performance of protective materials.…”

The Investigation of Performance Properties of the Epoxy/Glass Flake Composite Coating on Steel Pile Pipes

“…Salt spray test results have been associated with results obtained from atmospheric interaction in subtropical environments, increasing its validity [11]. In addition, the accelerated non-electrochemical test is the salt spray test, which is widely used for coating evaluation [12].…”