Update on the Development of an Improved Cosmetic Corrosion Test by the Automotive and Steel Industries

Abstract

The American Iron and Steel Institute's (AISI) Task Force on Automotive Corrosion is making significant progress in its continuing efforts towards development of an accelerated laboratory test for ranking the cosmetic corrosion resistance of automotive steel sheet products. This paper provides an overview of this work and reviews major accomplishments to date. Accelerated tests conducted by the AISI and by the SAE's Automotive Corrosion and Prevention Committee (ACAP) Division 3 are compared to long-term on vehicle exposure tests now in progress for four years in Montreal, Quebec and St. John's, Newfoundland. A license-plate exposure test has also been initiated to broaden the basis for real-world performance. Statistical methods for comparing the results of the various tests are described. A designed experiment (Plackett-Burman L8) is under way to evaluate the effects of seven key cycle test parameters on the rankings of the test materials in a laboratory cyclic corrosion test.

Corrosion Properties of Pulse-Plated Zinc-Nickel Alloy Coatings

“…14 There have been many studies of corrosion properties of DC-plated Zn-Ni alloy coatings using the salt-spray test 7,11,[15][16][17][18][19] and the potentiodynamic polarization test, 13,[17][18][20][21][22] but there have been no such studies on pulse-plated Zn-Ni alloy coatings. Corrosion properties must be established before pulse-plated Zn-Ni alloy coatings can be put to industrial use.…”

License Plate Cosmetic Corrosion Test of Automotive Coated Steel Sheet

“…[6][7] Methods were developed for comparing the results of the various tests to those of the real-world standard. [1][2]8 These comparisons clearly showed that none of the existing test methods evaluated was completely satisfactory. In particular, all of the evaluated tests underestimated the performance of zinc and zinc-alloy coated sheet relative to bare, cold-rolled steel sheet.…”

“…This group joined forces with the Society of Automotive Engineers Automotive Corrosion and Prevention (SAE/ACAP) Cosmetic Corrosion Subcommittee, (2) and the two groups proceeded with the test development. The Auto/Steel Partnership (ASP) (3) added its support in 1995.…”

“…The steps included in this development have been documented in a series of papers. [1][2][3][4][5][6][7][8][9][10][11][12][13] First, a reservoir of standard test materials was established. These included cold-rolled and coated sheet products representing a broad range of performance.…”

Wet/dry accelerated laboratory test to simulate the formation of multilayered rust on carbon steel in marine atmospheres

“…However, the classic salt fog test has a bad reputation and is unanimously considered to offer poor reproducibility and correlation with atmospheric exposure [11]. The application of intermittent salt spray, on the other hand, is a much better approximation to marine and coastal conditions [12,13], and the cyclic salt fog test, along with the use of alternative saline solutions to NaCl, provides much better correlations [14,15].…”