Influence of climatic factors in cyclic accelerated corrosion test towards the development of a reliable and repeatable accelerated corrosion test for the automotive industry

Abstract

Two designs of experiments made of nine accelerated tests each were used in order to study the influence of a selection of important climatic parameters such as the concentration of NaCl, the drying level, the basic humidity cycle, the frequency of salt spray and the temperature. The accelerated corrosion tests were all performed using automatic chambers. Different automotive materials were selected in order to study the resistance to cosmetic corrosion, perforation corrosion and bi-metallic corrosion. For cosmetic materials, coated panels of cold rolled steel (CRS), zinc-coated steel and aluminium alloys were chosen. Perforation corrosion was investigated using crevice panels of CRS, zinc-coated steel or different grades of aluminium alloys. From the results, the influence of testing conditions on the cosmetic and perforation corrosion of different automotive materials was obtained. As an example, it was shown that an elevation of the temperature from 35 to 45 8C in the cyclic corrosion test increased the scribe creep on painted CRS and aluminium alloys while it has no significant effects on painted hot dip galvanized (HDG) panels. The results were also compared to that obtained after 2 years of exposure at a marine exposure site and on busses driving in area using de-icing salt. It was shown that one of the tests performed gives a good correlation to field results.

A new accelerated corrosion test for marine paint systems used for ship's topsides and superstructures

“…The splash zone location in Panama is severe for zinc materials due to the frequent spraying of seawater aerosols which is known to accelerate the degradation of zinc materials. This has been shown in a previous study on painted galvanized steel . While systems A3 also contains a zinc primer, it is obviously less resistant compared to the other zinc‐based primers and behaves more or less like any epoxy barrier paint.…”

“…This has been shown in a previous study on painted galvanized steel. [9] While systems A3 also contains a zinc primer, it is obviously less resistant compared to the other zinc-based primers and behaves more or less like any epoxy barrier paint. Evidence of such behavior of paint system A3 has indeed been proved using a scanning Kelvin probe instrument in a recent paper from Nazarov and co-workers.…”

Automotive Corrosion and Accelerated Corrosion Tests for Zinc Coated Steels

“…19) However, the reproducibility of the corrosion behaviors of automotive parts in actual use environments by CCT is still a remaining issue to be solved. [20][21][22] Investigations of corrosion in vehicles in snowy areas have been carried out and reported in some publications. [23][24][25][26][27][28] Those investigations clarified the fact that the coating thickness is a more crucial factor than the alloy composition of the coating for prevention of cosmetic and perforation corrosion in automotive parts.…”

Corrosion performance and mechanical properties of joined automotive materials

“…The corrosion resistance of lap joints and the effect of their mechanical properties have been essentially studied in laboratory including tests in solutions 6, 12, 13, 16–18. Couple of studies were performed in accelerated corrosion tests such as salt spray, GM9540P, CCTIV, or specific tests 3, 4, 10–12, 19–21. Only few studies related to field exposures in stationary sites 3, 5, 10, 22 or on‐vehicles 5, 19.…”