Heating Performance of Atmospheric Plasma Sprayed Ceramic-based TiOx/Cr2O3 Coating System in Low-temperature Environments

Freezing water in pipes can cause severe damage, leading to costly repairs, particularly in cold regions. Traditional insulation and heat tracing methods provide limited protection and often prove inefficient during prolonged exposure to freezing temperatures, underscoring the need for a more reliable solution. Heating coatings offer uniform heat distribution, improving protection in both short-term and long-term scenarios. A ceramic-based heating coating made of TiO_x/Cr₂O₃ was investigated for its heating properties at extremely low temperatures from -25 °C to 5 °C. The coating was fabricated using atmospheric plasma spraying on pressure vessel steel P265GH, with a Ni20Cr adhesion layer and an Al₂O₃ insulation layer. Joule heating experiments in a controlled environment revealed that the coating’s electrical resistance decreases as surface temperature increases, leading to higher power output. Tests at various initial temperatures showed that less power was needed to reach a target surface temperature of 15 °C as ambient temperatures decreased. The ceramic-based TiO_x/Cr₂O₃ coating demonstrated a high rate of temperature increase due to the temperature-dependent electrical resistance of the coating. This characteristic allows for reduced initial power input, resulting in energy and cost savings, making the ceramic coating an effective potential solution for de-icing and heating applications in low-temperature environments.