PURPOSE: To obtain an excellent painting surface and good aesthetic appearance by forming the fine shapes to constitute the surface roughness of the surface of a steel sheet in such a manner as to satisfy the specific equation.
CONSTITUTION: The fine shapes of the steel sheet which constitute the surface roughness thereof as the steel sheet for painting are constituted of regularly arranged peak parts, valley parts and flat parts. The steel sheet has the fine shapes which satisfy the equations when the surface characteristics are evaluated overall by using the three parameters obtd. by three-dimensionally measuring and analyzing the fine shapes with respect to the specified area of the surface, i.e., flat area rate W2α(%), central surface average roughness SRa(μm) and central surface waving SWca(μm). The excellent painting surface is thereby obtd. and the good aesthetic appearance is obtd. in the case of using this steel sheet as an outside plate material of automobiles, etc.
UCHIDA HIROYUKI
FURUKAWA KUSUO
Next Patent: PRODUCTION OF HIGH BRIGHTNESS COLD-ROLLED STEEL SHEET