Coated Products
Steel demonstrates improvement of corrosion resistance and addition of new functions when nano-to-micron scale surface coating techniques are applied. Taking advantage of JFE Steel’s outstanding hot dip galvanizing and surface modification technologies, the Coated Products Research Department is developing coated steel sheets for automotive use with new functions, leading the world in this key field.
Hot Dip Galvanizing Technology
Some of the various elements added to high strength steel deteriorate hot-dip galvanizing property. To develop environment-friendly surface-coated steel sheets which satisfy both high strength and high corrosion resistance requirements, JFE Steel has been conducting research on technologies for controlling/modifying the steel surface before galvanizing.
Functional Surface Modification Technology
Front fender model panel (JFE Zn-coated steel sheet with excellent lubrication)
To improve press formability of the steel sheets for automotive use, Coated Products Research Dept. is has been developing a line of original Zn-coated steel sheets with excellent lubrication. Based on press-formability evaluations using a 1200 ton press testing machine, JFE Steel proposes the original materials and technologies to the customers.
High Function Chemical Conversion Coating Technology
Coating pilot line for high function chemical conversion coating
In some cases, the alloying elements added to high strength steel sheets inhibit crystallization of zinc phosphate in the automobile pretreatment processes and effect on corrosion resistance. Use of a technique which ensures the cleanliness of the surface of high strength steel sheets and a high performance treatment for uniform formation of nuclei for crystallization realizes a surface condition in which zinc phosphate crystallize stably.
Optimum Quality Design for Corrosion Resistance
Monitoring the corrosion environments of automobiles
Coated Products Research Dept. is studying the optimum quality design for corrosion resistance of coated steel sheets, based on use environments and designed life of automobiles. JFE Steel is researching into the corrosion mechanism of coated steel sheets in actual environments and establishing accelerated corrosion evaluation methods which are closely correlated with corrosion in actual environments, and on this basis, is proposing the quality guidelines for corrosion resistance of coated steel sheets for automobiles.
Atmospheric exposure test of actual automobile door parts (in Okinawa)
