Effect of type and thickness of paint film on the forming of galvanized steel sheet in mobarakeh steel company (msc)

Kafashan, H and Kafashan, A

Formability is on of the most important factors for pre-painted steel sheets (PCMs). In this study, tensile and formability properties of painted galvanized steel sheet with different thickness were investigated by tensile and deep drawing test, and the relationship between type and thicknesses of paint coated on the galvanized steel sheet with formability PCMs after deep-drawing were studied. Forming limit diagrams (FLDs) have been evaluated experimentally by stretch-forming sheet samples over a hemispherical punch. The effect of thickness of paint film on formability has been analyzed by using galvanized steel sheets that coated with different thickness of polyester and plastisol paint, and a comparison has been made with an uncoated galvanized steel sheet. The presence of resin in paint film appears to have a dominant role to decrease of coefficient of friction between punch and sheet. We found that with increasing of paint thickness in PCM, coefficient of friction between punch and sheet has been decreased. With decreasing of coefficient of friction between punch and sheet, formability of PCM could be better. Due to presence of PVC particle plastisol paint, galvanized steel sheet that coated with plastisol paint have better formability than polyester paint.