METHOD FOR DETERMINING SUPERIOR LACQUER ADHESION PROPERTIES OF A TIN-FREE STEEL SHEET

摘要

PCT No. PCT/JP84/00021 Sec. 371 Date Aug. 2, 1984 Sec. 102(e) Date Aug. 2, 1984 PCT Filed Jan. 27, 1984 PCT Pub. No. WO84/02931 PCT Pub. Date Aug. 2, 1984.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 ICr580/(ICr580+ICr660) has a value of 0.5 or more provided that ICr580 is the percent transmission corresponding to ol linkage and ICr660 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.