In the metallurgical steel production process, furnace rollers serve as the basic transmission and support components in key equipment such as continuous annealing lines and heating furnaces, and play an important role in transporting steel billets and strips in high-temperature environments. Its working environment has typical characteristics of high temperature, strong friction, and contact with corrosive media - being in the high temperature range of thousands of degrees Celsius for a long time, while directly contacting the surface of the strip steel to generate sliding friction, and also withstanding chemical erosion caused by protective gases or cooling media inside the furnace. These complex working conditions make the surface of the furnace rollers prone to wear, corrosion, and thermal fatigue damage, directly affecting the service life and production continuity of the furnace rollers. Next, let's follow Jiangsu Jinggong Machinery Manufacturer to learn about it from the main text.
Traditional furnace rollers often use alloy steel or surface welding processes, which can provide basic strength, but still have limitations under extreme working conditions. Alloy steel itself has limited hardness, and long-term friction is prone to plastic deformation; The bonding strength between the weld overlay and the substrate is insufficient, and it is prone to peeling under the influence of thermal stress, which actually exacerbates wear. At this point, thermal spraying technology, with its unique advantage of surface strengthening, has gradually become an effective means of extending the life of furnace rollers.
The core of thermal spraying technology is to heat coating materials (such as tungsten carbide and ceramic particles) to a molten or semi molten state through high-temperature flames, arcs, or plasma, and then use high-speed airflow to spray them onto the surface of furnace rollers, forming a functional coating that is tightly bonded to the substrate. Among them, supersonic tungsten carbide spraying and plasma ceramic coating are two typical processes that provide solutions for different wear and corrosion scenarios of furnace rollers.
Supersonic tungsten carbide spraying accelerates tungsten carbide powder to supersonic state through compressed air, causing it to collide with the surface of furnace rollers with high-density particle flow, forming a composite coating of mechanical interlocking and metallurgical bonding in severe collision. Tungsten carbide itself has extremely high hardness and wear resistance, and its coating microstructure is dense, which can effectively resist the mechanical friction of steel billet movement and reduce surface material loss. Meanwhile, tungsten carbide has good chemical stability and can resist the chemical erosion of slag to a certain extent, delaying the corrosion process.
Plasma ceramic coating utilizes the ultra-high temperature generated by plasma arc to melt ceramic powder, forming a thicker and more firmly bonded coating. Ceramic materials, such as alumina and chromium oxide, have excellent high temperature resistance and can form insulation barriers on the surface of furnace rollers, reducing thermal conduction losses of the substrate; It has stronger corrosion resistance and can effectively resist long-term erosion from oxide scale, acidic or alkaline slag, especially suitable for furnace roll protection in high-temperature corrosive environments.
The collaborative application of two processes can further enhance the comprehensive performance of furnace rollers. For example, in areas where the furnace rollers are prone to wear (such as the contact section of steel billets), supersonic tungsten carbide spraying is used to enhance wear resistance, while plasma ceramic coating is stacked in areas prone to corrosion (such as near the furnace mouth) to enhance corrosion resistance, forming a "wear-resistant anti-corrosion" composite protection system. This layered protection strategy not only extends the service life of furnace rollers, but also reduces the overall replacement risk caused by local failure.
From a practical production perspective, the surface wear rate of furnace rollers treated with thermal spraying can be significantly reduced, and the replacement cycle can be extended from the traditional few months to over a year. This not only reduces the downtime for replacing furnace rollers, but also lowers spare parts procurement and labor costs. More importantly, a stable surface condition of the furnace rollers can ensure the smoothness of steel billet transportation, reduce defects such as scratches and pits on the steel billet surface, and indirectly improve the surface quality of steel products.
In the current pursuit of high efficiency and low consumption in the metallurgical and steel industry, surface strengthening technology for furnace rollers has become an important part of equipment management. The supersonic tungsten carbide spraying and plasma ceramic coating processes provide feasible solutions for furnace rollers to cope with multiple challenges such as high temperature, friction, and corrosion through targeted surface performance optimization. This technology not only solves the limitations of traditional materials, but also improves practical performance, becoming a key support for extending the service life, reducing costs, and increasing efficiency of metallurgical steel equipment.