SURFACE TREATMENT OF STEEL MATERIAL

摘要

PURPOSE:To improve the water resistance of a steel material used for the torque transmitting part of an automobile driving system by subjecting the steel material to specified phosphating, applying nylon resin, etc., and carrying out baking. CONSTITUTION:A phosphating soln. contg. 0.5-3g/l Ni<2+>, <=1g/l Mn<2+> and 0.5-10g/l Zn<2+> and having 0.1-0.9 molar ratio of Ca to Zn and 0.3-1.5 molar ratio of Zn+Ca to PO4 is prepd. A steel material used for the torque transmitting part of an automobile driving system utilizing interlocking with a spline is treated with the phosphating soln. to improve the heat resistance. Primer is then applied and nylon resin is further applied and baked.