A high-strength spring steel and a spring are provided that have superior corrosion fatigue strength. A color of a target pixel is calculated based on the area color information and the target pixel is filled with the calculated color when the target pixel is a boundary pixel. The top surface forms at least one tenon projection, and the lower surface forms a mortise slot corresponding to the tenon projection in shape, size, and position, so that two carriers can be stacked on and jointed to each other by coupling the tenon projection to the corresponding mortise slot. Additionally, the body of each article molding region of the \u201cA\u201d surface mold tool is adapted for molding a bottom surface for the composite article, and the body of the article molding region of the \u201cB\u201d surface mold tool is adapted for molding a top surface for the composite article. The resulting yellow coating is amenable to overlayering with a seal coat.