Thermal spraying is suitable for spraying of converter flues and hoods in steel mills

       Thermal spraying is suitable for spraying of converter flues and hoods in steel mills:



The flue gas generated in the steelmaking process has a temperature of up to 1100-1400 °C, and a high temperature of 1600 °C, and contains a large amount of dust such as sulfur and its compounds, high-temperature slag, and lime. Therefore, the heating surface is subject to the erosion of solid materials, the corrosion of acid gas and high temperature oxidation, and the splashed high-temperature slag is easily blown to the heating surface to form high-temperature erosion and slag. The hood and flue work in the above environment for a long time, and the working environment is harsh, especially the heating surface is subjected to sulfur gas corrosion, high temperature oxidation and erosion wear, and it is easy to produce a large number of bamboo-shaped thermal fatigue cracks and pitting on the water-cooled pipe. , Perforation and leakage, affecting the production efficiency of steelmaking. Therefore, starting from the corrosion mechanism, it is very necessary to take more effective anti-corrosion measures for the stable and economical operation of the converter.

Using advanced supersonic arc spraying technology and materials, superb technology, and sophisticated equipment, it provides reliable and economical solutions to the corrosion and wear problems of flue/smoke hoods in steel mills. Supersonic arc spraying uses two continuously fed metal wires as consumable electrodes, generates an arc at the end as a heat source, atomizes the melted wire with compressed air, and sprays it to the workpiece at supersonic speed. A thermal spray method for coatings with high bond strength, low porosity, and low surface roughness. It is especially suitable for protective spraying of boiler tube wall due to the following process characteristics.

1. The particles have high flying speed and are well combined with the matrix.



2. The particles are small and the porosity is low.



3. The deposition efficiency is high, and the coating structure is dense.



4. High arc stability.



5. There is no thermal deformation of the sprayed substrate.



6. After the first spray has been eroded away, it can be sprayed a second time.