Anti-Corrosion Performance and Applications of PosMAC® Steel

  • Sohn, Il-Ryoung (Automotive Steel Surface Research Group, POSCO Technical Research Laboratories) ;
  • Kim, Tae-Chul (Automotive Steel Surface Research Group, POSCO Technical Research Laboratories) ;
  • Ju, Gwang-Il (Surface Treatment Dept, POSCO Gwangyang Works) ;
  • Kim, Myung-Soo (Automotive Steel Surface Research Group, POSCO Technical Research Laboratories) ;
  • Kim, Jong-Sang (Automotive Steel Surface Research Group, POSCO Technical Research Laboratories)
  • Received : 2020.10.12
  • Accepted : 2021.01.25
  • Published : 2021.02.26


PosMAC® is a brand of Zn-Mg-Al hot-dip coated steel sheet developed by POSCO. PosMAC® can form dense surface oxides in corrosive environments, providing advanced corrosion resistance compared to traditional Zn coatings such as GI and GA. PosMAC® 3.0 is available for construction and solar energy systems in severe outdoor environments. PosMAC®1.5 has better surface quality. It is suitable for automotive and home appliances. Compared to GI and GA, PosMAC® shows significantly less weight reduction due to corrosion, even with a lower coating thickness. Thin coating of PosMAC® provides advanced quality and productivity in arc welding applications due to its less generation of Zn fume and spatters. In repeated friction tests, PosMAC® showed lower surface friction coefficient than conventional coatings such as GA, GI, and lubricant film coated GA. Industrial demand for PosMAC® steel is expected to increase in the near future due to benefits of anti-corrosion and robust application performance of PosMAC® steel.



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