| 摘要 |
<p>In a method for providing steel parts with protective coatings including successive layers of zinc and chromate, the zinc layer being applied by zinc electroplating and the parts beings washed with water prior to application of the chromate layer, the continuous treatment of the parts comprises : immediately following the water washing of the zinc-plated parts and while the parts are still wet, spraying the parts with an aqueous chromating solution containing chromic acid together with nitric acid and a least one salt providing activator anions, said chromating spraying wetting the exterior surfaces of the parts and being completed in not over 120 seconds with the formation of a yellow chromate layer on the parts. <IMAGE></p> |
