Fraktografische und mechanische Analyse von bandbeschichteten Blechen

Research output: Thesis › Master's Thesis

Authors

Abstract

In this thesis focus is given to the analysis of deformation induced failure mechanisms in coil coated steel sheets. Failure of coil coatings is characterized by cracks and loss of adhesion. Four coating systems were investigated. Deformation was applied in a T-Bend test. Light microscopy was used for the measurement of local strain distribution and to evaluate the crack formation. As characteristic values the number and width of cracks and an integral parameter were determined. For adhesion analysis automated and manual peel off tests were implemented and applied. The obtained force-displacement curves and the microscopic images were evaluated to characterise the adhesion behaviour. By local strain measurement for T-Bend values equal or higher than 0.5T higher strain values were obtained compared to values reported in the T-Bend standard EN 13523. The crack analysis revealed a significant effect of various zinc coatings on the amount and width of cracks. All investigated primercoatings showed a brittle failure. For basecoatings significant differences in the amount and width of cracks were obtained. Furthermore the curing temperature had a significant impact on number and width of cracks. In adhesion analysis the peel off force and the amount of failed coating were significantly dependent on testing speed. Furthermore significant differences in adhesion performance were obtained for the investigated coatings.

Details

Translated title of the contributionFractographical and mechanical analysis of coil coatings
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date30 Mar 2012
Publication statusPublished - 2012