Prepainted Sheet Steel for Outer Automobile Body Panels: Paint Deformation Behavior 950380
The paint deformation behavior in fully prepainted sheet steel intended for outer automobile body panels is examined in three categories: paint sliding behavior during forming, paint surface roughening during straining leading to loss of coating reflectivity, and dry heat cracking (i.e. time and temperature dependent post-forming paint cracking resulting from viscoelastic strain relaxation). The main findings are: frictional behavior is dictated by the outer coating while pigment particles tend to decrease the measured coefficient of friction; the loss of distinctiveness of image with strain is a result of shear band formation, an inherent deformation mechanism within the polymer coatings; and, dry heat cracks evolve in a two step process where crack nuclei develop during forming and grow as a result of viscoelastic strain relaxation in the coating upon subsequent exposure to heat. Furthermore, pigment particles tend to increase the resistance of a paint coating to the effects of viscoelastic relaxation.
Citation: Kyed, P. and Matlock, D., "Prepainted Sheet Steel for Outer Automobile Body Panels: Paint Deformation Behavior," SAE Technical Paper 950380, 1995, https://doi.org/10.4271/950380. Download Citation
Author(s):
Paul J. Kyed, David K. Matlock
Pages: 11
Event:
International Congress & Exposition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
SAE 1995 Transactions: Journal of Materials and Manufacturing-V104-5
Related Topics:
Body panels
Coatings, colorants, and finishes
Particulate matter (PM)
Steel
Forming
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