License plate cosmetic corrosion test of automotive coated steel sheet

A new standard laboratory test (SAE J2334) for evaluation of the cosmetic c orrosion resistance of autobody steel sheet has been developed through the joint efforts of the Society of Automotive Engineers Automotive Corrosion P revention Committee (SAE/ACAP) and the Auto/Steel Partnership (A/SP) Corros ion Task Force. Results from this test gave an excellent correlation with t hose of on-vehicle tests conducted for 5 years in Canada at Si. John's, New foundland, and Montreal, Quebec, To determine how results of the Canadian t ests related to environments in the United States, racks of identical mater ials were mounted on the front license plate brackets of cars driven in var ious locations in the U.S. snow-belt, including Bethlehem, Pennsylvania; De troit, Michigan; and Chardon, Ohio. After 4 years to 5 years, these tests s howed the U.S. environments produced less scribe creep and more red rust th an those conducted in Canada. Similar rankings were obtained for the scribe creep resistance of the various coated steel sheet products when compared at equivalent amounts of corrosion, However, the ranking of materials chang ed at longer exposure times in Canada, and for that reason, it was conclude d that the 5-year Canadian results used in the development of the SAE J2334 test provided a better real-world performance standard.