Metallurgical Criterion for Continuous Casting Slab Solidification and Cooling
Introduction
The continuous casting process is a key process in the steelmaking industry. Through this process, liquid steel is poured into a foundry and cast into a slab shape, which then cools and solidifies. As one of the most essential process steps in steelmaking, the cooling and solidification process has a great influence on the metallurgy of the final product. In this article we will discuss the metallurgical criterion for the continuous casting slab solidification and cooling process.
Background
In order to ensure the quality of the steel, a scientific and rational solidification and cooling process must be designed. During the solidification and cooling process, the cooling rate, temperature gradient, and the structural morphology of the slab must be strictly controlled in order to minimize the segregation and grain size refinement caused by certain external forces such as thermal stress, convective heat transfer, and internal oxidation.
Metallurgical Criterion
In order to design a continuous casting process that meets the quality standards, there are certain principles to follow. These principles are known as the metallurgical criteria for continuous casting slab solidification and cooling.
1. Temperature Control
Mold temperature is an important factor that affects the performance of the continuous casting process. The mold temperature must be carefully controlled to minimize the thermal stresses and oxidation caused by excessive cooling. The ideal mold temperature should be set between 800°C to 1100°C.
2. Layer Control
The liquid steel should be poured in layers in order to ensure a low thermal gradient and uniform cooling of the slab. Each layer should not be thicker than 10 mm, and in order to ensure a uniform distribution of cooling, the slab should be cooled symmetrically throughout the entire casting process.
3. Heat Transfer
In order to ensure a stable and uniform cooling, the slab should be designed to allow for efficient heat transfer. The cooling media should have high contact area with the slab surface and the thermal conductivity should be suitable for the desired cooling rate and temperature gradient.
4. Structural Stability
It is important that the slab should be structurally stable during and after the cooling process. The slab should be designed to minimize thermal stresses and cracking during cooling. In addition, the mold should provide sufficient support for the slab during solidification and cooling in order to prevent deformation or cracking.
Conclusion
In this article we have discussed the metallurgical criteria for the continuous casting slab solidification and cooling process. To ensure the quality of the steel, the temperature control, layer control, heat transfer and structural stability should all be strictly controlled. By carefully designing the solidification and cooling process to meet these criteria, the quality of the steel product can be ensured.
