Chrome Carbide Coating
Chrome Carbide is a ceramic material and is grey in color. Being a carbide, it is inherently hard and stiff. It exists in three different crystalline forms, each varying in hardness and corresponding to different chemical compositions. The most durable form is the one most commonly referred to as Chrome Carbide. It has a much higher hardness number than other variation such as Cr7C3 and Cr23C6 and is frequently employed in surface engineering treatments and coatings.
Chrome Carbide is a hard-refractory compound that possesses superior corrosion resistance and thermal stability over a wide range of high temperatures. Due to its excellent high temperature wear resistance imparted by the chromium carbide particles, this material when applied via thermal spray coating, offers great high-temperature oxidation resistance due to the chromium oxide (Cr2O3) layer which is stable at high temperatures.
Selection Criteria for Chrome Carbide:
The selection of any coating depends on the application under consideration or the use of the coated part. Keeping this is a consideration, Chrome Carbide coatings are mainly used in applications where the material is exposed to high temperatures and high wear. These coatings are generally employed in a high-temperature application, although costly, are less costly than WC coatings, which are less effective than Chrome Carbide coatings when dealing with high-temperature wear.
Properties of Chrome Carbide Coatings:
- Good hardness
- Superior strength
- Excellent high temperature wear resistance
- Good corrosion resistance due to the formation of passive Cr2O3 and NiO2 layer from Chromium-Nickel matrix
- Excellent oxidation resistance
- Excellent thermal shock resistant
- Prevention from chemical attack
- High bond strength
- Low porosity
- Dense coating
Chrome Carbide Potential Benefits:
- Coating maintains hardness up to approximately 1598 °F and is considered the highest temperature stable carbide.
- It offers excellent oxidation resistance at elevated temperatures.
- With Chrome Carbide coatings, the service life is enhanced, and repair durations are increased.
- Resistant against a variety of corrosion types i.e. cavitation damage, fretting, erosion corrosion.
- Coating technology is efficient and reliable.
- It offers a good combination of mechanical and metallurgical properties.
- Thick coatings of Chrome Carbide may undergo delamination.
- Thick coatings may easily crack and become brittle.
- Coating thickness must be monitored.
- Linings of steel furnaces for thermal wear resistance during the steel making process.
- When wearing occurs due to surface contact. Such applications include gas turbine combustion parts and expander blades.
- Turbine components where severe wear damage is likely and is magnified by high-temperature conditions, especially in steam turbine blades and turbine diaphragms.
- Coal-powered boilers. The tubing systems are exposed to severe temperature, wear, and erosion conditions which make Chrome Carbide coatings a good alternative.
- Wear protection in pump impellers, piston rings, hydraulic equipment, ball valves and seats.