1991 Volume 77 Issue 7 Pages 1177-1183
Paint loss at the sheared and punched edge of pre-painted galvannealed steel sheet, so called enamel-hair, deteriorates corrosion resistance at the edge and mars appearance of paint film.
Effect of paint film and punching condition on the paint loss was investigated and this behavior was discussed by applying strain-induced grain growth. The results are summarized as follows;
(1) Polyester powder paint produced more paint loss than acryl solvent paint.
(2) Paint loss increased with an increase in punching clearance, an increase in punching speed and a decrease in punching temperature.
(3) Putting protect film on paint film increased paint loss in case of polyester powder paint and decreased paint loss in case of acryl paint.
(4) Microstructure of deformed base steel at the punched edge was studied by the strain-induced grain growth method. Behavior of paint loss can be explained by strain distribution at the edge and properties of paint film.
