| 摘要 |
PURPOSE:To provide excellent resistance to wear by heat treating a film manu factured by the electric plating process in a bath of plating solution composed of chromic acid, sulfuric acid and trivalent chromium to which organic acid is added. CONSTITUTION:A plated layer 1 is formed on a matrix 2 by the electric plating process in a bath of plating solution composed of chrome acid, sulfuric acid and trivalent chromium to which organic acid is added. Then, the plated layer 1 is heat treated to form a high hardness plated film and manufacture a screw desired for a plastic molding machine. |
