Chromium coatings crack-free

Chromium coatings are applied as a thin layer to maintain a bright, tarnish-free surface. Cracking of chromium coatings begins at a thickness of 0.5 pm after which a network of fine cracks is formed. [Pg.278]

Microcracked chromium coatings are produced by first depositing a high stress nickel strike on a sulfur free nickel layer and then a decorative chromium deposit. The uniform crack network results from the interaction of the thin chromium layer and the high stress nickel deposit. The result is a mirror surface as well as a decorative chromium coating. [Pg.375]

In the natural atmosphere noble metal coatings, such as chromium, nickel, and their alloys, form passive films on carbon steel surfaces. A defect-free continuous layer of chromium provides excellent protection for a carbon steel substrate. However, deposited layers of chromium and nickel commonly have some defects, such as cracks. The corrosion rate of the carbon... [Pg.229]

The electrochemical aspect of the process is associated with anodic dissolution, accounting for high cracking velocities. The crack tip is free of the oxide protective coating in the alloy, and crack propagation proceeds as the alloy dissolves. Chloride ions present in solution tend to destroy this passivity in the crevice, which is depleted in oxygen. In stainless steels, the dissolution of chromium in the crevice occurs by the reactions ... [Pg.183]

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