PURPOSE: To produce a galvannealed steel sheet excellent in press formability, image clarity after coating and powdering resistance.
CONSTITUTION: This is a galvannealed steel sheet in which a galvannealing layer is formed on at least one surface of a steel sheet, and on the galvannealed layer, many fine recessed parts in which the integral value of 100 to 2000μm of the wavelength of the power spectrum obtd. by subjecting the cross-sectional curve on the surface to Fourier transformation is regulated to ≤200μm3 and the integral value of 15 to <100μm of the wavelength of the power spectrum is regulated to ≥0.15μm3 are formed. Thus, the improvement of its press formability, image clarity after coating and powdering resistance can be attained.
INAGAKI JUNICHI
WATANABE TOYOFUMI