Tin-free steel sheets having improved lacquer adhesion
AssigneeKawasaki Steel Corporation
InventorsHajime Ogata, Yoshiharu Ohashi, Shunichi Tsugawa, Toshio Ichida, Toshio Irie
Life of this patent
Estimating the term…
Abstract
This invention provides a tin-free steel sheet, having superior lacquer adhesion, comprising metallic chromium and chromium oxide coatings on a steel sheet, characterized in that the chromium oxide coating is controlled such that I.sub.Cr.sup.580 /(I.sub.Cr.sup.580 +I.sub.Cr.sup.660) has a value of 0.5 or more provided that I.sub.Cr.sup.580 is the percent transmission corresponding to ol linkage and I.sub.Cr.sup.660 is the percent transmission corresponding to oxo linkage in the infrared absorption spectrum of said chromium oxide coating as measured by Fourier transform infra-red spectroscopy.
Claims1
A tin-free steel sheet having metallic chromium and chromium oxide coatings on a steel sheet, characterized in that for improved lacquer adhesion, I.sub.Cr.sup.580 /(I.sub.Cr.sup.580 +I.sub.Cr.sup.660) has a value of 0.5 or more provided that I.sub.Cr.sup.580 is the percent transmission corresponding to ol linkage and I.sub.Cr.sup.660 is the percent transmission corresponding to oxo linkage in the infrared absorption spectrum of said chromium oxide coating as measured by Fourier transform infra-red spectroscopy (FTIR).
Dependencies are inferred from the claim text.