Area elements of iron, steel or special steel covered with a protective layer

摘要

The protective layer on area elements in the form iron, steel or special steel plates or sheets consists of galvanically applied hard chromium, with a layer thickness of at least 0.001 mm. Independent claims are also included for a method and an apparatus for production of such protective layers. The area element (3) is placed into a bath (2) consisting of 200-250 g CrO3 and 2-2.5 g H2SO4 per liter of water. Galvanic application of the protective layer takes place preferably after roughening of the area element surface by voltage polarity reversal at the area element and the anode (4). The surfaces not to be coated are provided with capture electrodes at a specified distance from such surfaces. These electrodes have the same polarity as the surfaces to be coated.