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Goltigore The present invention relates to chromium VI -free chromate according to claim 1, a method for their preparation according to claim 4, a concentrate according to claim 7, a passivation bath according to claim 11, a method for passivating according to claim 17 and a passivation layer according to claim 21st. The new greenish chrome VI chromate is accordingly depending on the production temperature between and nm thick, pale green in color and the natural red-green iridescent.
In Figure 1, the layer thickness profiles for different values of the rate constants are shown j k. The formation of conversion layers is a process beyond the chemical equilibrium. Figure 4 shows the average values of the chromitierten there parts as well as practical values of trivalent and hexavalent blue yellow chromates from various plants. Schwarzchromatierungen auf Zinklegierungen liegen erheblich oberhalb der genannten Werte.
Chromium III complexes generally have slow kinetics. In our industrial society galvanized and chromated metal surfaces are omnipresent. Therefore, it is object of the present invention to provide a cin VI -free, thick chromate film with a high chromium content on zinc, cadmium or aluminum are available.
The risk of cancer by the contact of z. Table 2 shows for chromating zinc according to the prior art. Bild 3 zeigt die Bruchkante eines glanzverzinkten und chromitierten Stahlbleches bei Mixtures for the coating of metal surfaces containing organic corrosion inhibitors.
Bild 4 zeigt die Mittelwerte der dort chromitierten Teile sowie Praxiswerte xin dreiwertigen Blau- und sechswertigen Gelbchromatierungen aus diversen Anlagen. Steel is galvanized to protect it from corrosive environmental influences. Das betreffende verzinkte Bauteil bleibt unversehrt, solange es noch durchgehend mit Zink bedeckt ist. Die Bruchkante Bild 3 eines glanzverzinkten und dreiwertig passivierten Stahlbleches bei Immersion time was 30 seconds.
Use of a treatment solution for forming an anti-corrosive coating layer on a metal dispersion dry film or on a surface of a micron-scaled metal particle. The production method according to Example 1 for the new greenish chromium VI -free chromate is not very economical for conventional plants because of the relatively high temperature of the process solution. The chromate coating consists essentially of water-dissolved hexavalent chromate, conducting salts and mineral acids, in particular phosphates or phosphoric acid and may also contain formates.
For this, there are the following approaches: Wohingegen die Fluoridkomplexe kinetisch sehr stabil sind. This effect is not given with a layer such as the Chromiting consisting purely of sparingly soluble oxide compounds. A low pH favors the dissolution of zinc, but also provides for increased redissolution of the layer.
Here the layer is scratched by friction under the weight of superimposed and each other by falling parts, especially when dim so when the layer is still partially gel-like.
ZnCrO m 2 taken into account that reaction I by the growing passive layer is increasingly slowed down. Since the Chromiting is not specified as a new layer, ein editors of norms and standards are now invited to evaluate the properties of this coating itself.
The presence of chromium VI in chromate is attributed to a corrosion-protective effect. DIN Seite 7. The advantages of an applied chromate are so important that almost any galvanically zinc-plated surface is additionally chromated. BS Testing coated fabrics. For good corrosion protection, the passive layer should be thick and at the same time as compact as possible.
Further advantages and features of the present invention will become apparent from the description of exemplary embodiments and based on theoretical cin that are not binding on the one hand and on the other hand have been made having regard to the present invention sin the inventors. The differential equation system is solved numerically by means of computer.
Hot-dip galvanized parts are chromitierbar. The number and rating of specimens with a significant surface area smaller than 25 mm2 is to be agreed. Die Tauchzeit betrug 30 s. If this were fin, then one would with trivalent chromate coatings in terms of the achievable corrosion protection always at a disadvantage.
During the ongoing third attempt in a practice Electroplating were essentially drum parts, but also coated some parts in the frame method. By using appropriate ligands, the reaction rate should be accelerated.
Further theoretical reflections on chromium VI -free chromate coating and further trials finally resulted in economical production conditions. German Federal Law Gazette 1, No. Dln EN Corrosion protection of metals — Non-electrolytically applied zinc flake coatings on iron or steel components. TOP Related Posts.
DIN 50961 FE ZN PDF