With the rapid development of society and science and technology, a series of environmental and ecological harmony problems have emerged. Carbon dioxide emissions negatively impact the development of current thermal power plants. Research shows that increasing steam pressure and temperature during operation is the most effective way to solve these problems. Since heat-resistant steel is primarily used in the main high-temperature components of thermal power plants, developing new heat-resistant steels, increasing their operating temperature range, and enhancing their creep rupture strength at higher temperatures has always been a hot research topic in the fields of metallurgy, power generation, and materials science.
Continuous casting of heat-resistant steel can not only improve the yield of molten steel, eliminate the ingot casting process, significantly reduce energy consumption, and significantly improve production efficiency. Continuous casting results in a uniform structure and less segregation, and the labor intensity of continuous casting production is also lower. Therefore, continuous casting is an important measure for improving quality and reducing costs in heat-resistant steel production, and it is also one of the important symbols of modern production.
Continuous casting of heat-resistant steel has higher requirements in terms of process and equipment than continuous casting of ordinary steel. For example, continuous casting of heat-resistant steel requires strict control of the temperature and chemical composition of the molten steel, and the casting temperature must be controlled within a relatively narrow range. To prevent secondary oxidation, non-oxidizing protective casting is required during the continuous casting process. Continuous casting of heat-resistant steel also has strict requirements for the refractory materials used in the ladle, tundish, sliding nozzle, and immersion nozzle. To improve the solidification structure of the casting, reduce defects such as inclusions, central segregation, central shrinkage cavities, and internal cracks, and obtain high-quality continuous castings, electromagnetic stirring technology is generally used. The cooling process of continuous casting of heat-resistant steel is different from that of ordinary steel; the casting must be placed in an annealing furnace at above 300°C for slow cooling to prevent martensitic phase transformation and the generation of deformation cracks. The quality requirements for continuous casting of heat-resistant steel are much stricter than those for ordinary steel.
