SURFACE-TREATED STEEL SHEET, PROCESS FOR PRODUCING THE SAME, AND RESIN-COATED STEEL SHEET

摘要

It is an object to provide a surface-treated steel sheet which contains no Cr, which is excellent in wet resin adhesion, and which can be used as an alternative to a conventional tin-free steel sheet and to provide a resin-coated steel sheet produced by coating the surface-treated steel sheet with resin. A surface-treated steel sheet including an adhesive layer which is disposed on at least one surface of the steel sheet and which contains Ti and at least one selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn, the ratio of the total amount of Co, Fe, Ni, V, Cu, Mn, and Zn to the amount of Ti contained therein being 0.01 to ten on a mass basis, and a method for producing the surface-treated steel sheet. A surface-treated steel sheet including an adhesive layer which is disposed on at least one surface of the steel sheet, which has a thickness of 20 to 800 nm, which contains Ti, and which has bumps arranged with a line density of one or more per µm. The thickness of the adhesive layer is defined as the maximum height H from the lower surface of the adhesive layer to the bumps in a cross-sectional profile of the layer observed with a transmission electron microscope (TEM). The line density of the bumps is defined as the number of the bumps per unit length, the number thereof being determined on the assumption that one of the bumps is present when one or more intersections of an upper-level horizontal line and a profile curve are present between two intersections of a lower-level horizontal line and the profile curve, the upper- and lower-level horizontal lines being +10 nm apart from a center line located at a position given by the formula (H + L) / 2, where L represents the minimum height from the lower surface of the adhesive layer to the bottom of a recessed portion.