This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Performance of Finish-Coated Galvanized Steel Sheets for Automotive Bodies
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2008 by SAE International in United States
Annotation ability available
Improving performance and reduction of cost are principal concerns for vehicle manufacturers. In addition to shape, the exterior finish is the first thing a consumer sees when looking at a vehicle. The quality and durability of the finish is a reflection of the quality and durability of the vehicle itself. In this work, the behavior of two finish coat systems was studied. Finish coat system 1 included a powder coat, a waterborne base coat and a clear coat. Finish coat system 2 included the same powder coat, a solvent based base coat and a clear coat. These finish coats were applied on unprimed and pre-primed electrogalvanized, hot dip galvanized and galvannealed steel. Before application, for each finish coat two activation treatments were considered: a conventional zinc phosphate for automotive industry and an experimental pretreatment. Three primers were considered. Primer 1 is an organic zinc rich silicate with a low thickness (near 4 μm), primer 2 is a very thin (near 2 μm) water based primer filled with graphite and primer 3 is a conventional electrophoretically applied primer system.
To evaluate the performance of finish coats, the samples were submitted to a cyclic corrosion test, and the paint coating adhesion was evaluated, before and after exposure, by a cross-cut test method.
Better adhesion was verified on the finish coat with a waterborne base coat, a system environmentally more convenient. Both finish coats presented good anticorrosive behaviour, without significant defects on undamaged areas. Regarding the scribe area, the performance at times seems to be better with the application of the conventional zinc phosphate pretreatment compared to the experimental pretreatment.
|Aerospace Material Specification||Thread Compound, Anti-Seize, Graphite-Petrolatum|
|Ground Vehicle Standard||Scribing of Coatings in Preparation for Testing of Wheels and Wheel Trim|
|Aerospace Standard||Handles and Attachments for Hand Socket Wrenches|
CitationSantos, D., Raminhos, H., Costa, M., Diamantino, T. et al., "Performance of Finish-Coated Galvanized Steel Sheets for Automotive Bodies," SAE Technical Paper 2008-01-1463, 2008, https://doi.org/10.4271/2008-01-1463.
- Muzu Chen “Present Status and Future Development of Automotive Finishing” Materials, Coatings and Finishing Consultation http://www.asiacoat.com/eng/emarkets/emarkets3.htm
- “A brief History and Trends in Vehicle Paints” 1999-2006 Protect All, Inc. Anaheim, CA, USA July 2006 http:/www.protectall.com/artpaints.htm
- Rink Heinz-Peter Mayer Bernd Prog. Org. Coat. 34 175 1998
- Prendi Lindita Henshaw Paul Tam Edwin K. L. International Journal of Environmental Studies 63 4 463 2006
- “Paints and varnishes - Determination of film thickness” ISO Geneva 2007
- “Paints and varnishes - Cross-cut test” CEN Brussels 2007
- “Testing of Corrosion Protection of Vehicle Paint by Alternating Cycles Test” VDA Frankfurt, Germany 1982
- “Evaluation of Weldable Corrosion Protection Primers for the Automotive Industry. Part 1: Corrosion Performance” Stahlinstitut VDEh Düsseldorf, Germany 2004
- “Standard Practice for Operating Salt Spray (Fog) Apparatus” ASTM PA, USA 2007
- “Climates and their technical application; standard atmospheres” DIN e. V. Germany 1985
- Goodwin F.E. Santos D. “Effect of lubrication and comparative formability performance of pre-primed coated automotive sheet steels” Galvanized Steel Sheet Forum Düsseldorf, Germany May 2006
- “Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 6: Laboratory performance test methods” CEN Brussels 1998
- “Paints and varnishes. Evaluation of degradation of coatings. Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 2: Assessment of degree of blistering” CEN Brussels 2003
- Santos D. Raminhos H. Costa M. Diamantino T. Goodwin F. “Performance of conductive pre-primers applied on galvanized steel sheets for automotive bodies” SAE World Congress & Exhibition Detroit, MI, USA April 2007 07M-390