12th International Conference on Zinc & Zinc Alloy Coated Steel Sheet - GALVATECH 2021

Advanced pre-painted steel sheets were developed by applying Zn-11%Al-3%Mg-0.2%Si coated steel sheets, which are greatly superior to mainstream galvanized steel sheets in corrosion resistance. The basic concept of the development was to create more environment-conscious products and the vital goals to realize the concept was following two. Firstly, they were aimed at much more durable even in a harsh environment such as heavy salt damage district. Secondly, they were aimed at much thinner in painted film keeping equivalent performances to conventional pre-painted Zn-0.2%Al coated steel sheets (pre-painted GI). In this paper, the development of the advanced pre-painted Zn-11%Al-3%Mg-0.2%Si coated steel sheets (pre-painted Zn-Al-Mg) for outdoor-appliances was mainly discussed. Some of the predominant challenges to practical use were shown and the fundamental properties of newly developed products which resolved those were also provided.