Orthorhombic crystals.
Highest oxidation resistance at high temperature of
all metal carbides also resistant to acids and alkalies.
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Chromium carbide (Cr3C2) ceramics has proved to be a potentially useful material because of its excellent electrocal conductivity, high degree of hardness,moderate melting point, and good chemical stability.
Chromium carbides are hard and their general use is to provide hard wear-resistant coatings on parts that need to be protected. When combined with a protective metal matrix, corrosion-resistant as well as wear-resistant coatings can be developed that are easy to apply and cost effective. These coatings are applied by either welding or thermal spray. When combined with other carbides, chromium carbide can be used to form cutting tools.
Chromium carbide welding electrodes are increasingly used instead of the earlier ferrochrome/carbon-containing electrodes, as they give superior and more consistent results. In ferrochrome/carbon-containing welding electrodes, chromium carbide is created during the welding process to provide a hard wear resistant layer. However, the formation of the carbides is determined by the precise conditions in the weld and therefore there can be variation between welds which is not seen with electrodes containing chromium carbide. This is reflected in the wear resistance of the weld deposit. Using the dry sand rubber wheel test, wear rates of welds deposited from ferrochrome/carbon electrodes have been found to be up to 250% greater compared to chromium carbide.
