In the modern steel industry, Continuous Casting is regarded as one of the most revolutionary technological
breakthroughs of the 20th century. It has revolutionized the traditional way of steel production, dramatically
improving productivity, energy efficiency and product quality. In this paper, we will analyze the operation
principle of continuous casting process, technical advantages and the far-reaching impact on the
development of the industry.
Continuous casting process basic principles and processes
Continuous casting process is the core objective of the high temperature liquid steel directly into solid steel billet,
eliminating the traditional mold casting process in the repeated heating and cooling steps. The basic process can
be summarized in the following four stages:
Steel preparation and refining
Liquid steel needs to be refined outside the furnace to adjust the composition, temperature and purity. This
process directly determines the mechanical properties and corrosion resistance of the final product.
Crystallizer forming
The molten steel is injected into the water-cooled copper crystallizer through the intermediate ladle, where it
solidifies rapidly on the surface to form the billet shell. The vibration design of the crystallizer effectively prevents
the steel from sticking to the mold and ensures uniform molding of the billet.
Secondary cooling and billet drawing
The initially solidified billet enters the secondary cooling zone, where it is cooled by a gradient of high-pressure
water mist. The synchronized drawing machine pulls the billet at a precise speed to achieve continuous production.
Cut-to-length and collection
The fully solidified billets are cut to the required length and transported to the collection area through the roller
conveyor to form semi-finished products (e.g. billets, slabs, etc.) that can be rolled directly.
Five technical advantages of the continuous casting process
Compared with the traditional die casting process, continuous casting technology through process innovation
to achieve a qualitative leap:
1. Energy consumption reduction of more than 30%
Eliminate repeated heating link, directly reduce fuel consumption and carbon emissions. The energy consumption per
ton of steel production is reduced to 60%-70% of the traditional process.
2. Increase in yield to 98%.
Continuous production avoids the loss of die casting head and tail cutting, increasing metal yield by about 15%
and significantly reducing raw material waste.
3. Revolutionary breakthrough in quality stability
The internal organization of billet is dense and uniform, and the defects such as segregation and shrinkage hole
are reduced by more than 80%, which lays the foundation for the preparation of high-end steel.
4. Doubling of production efficiency
The daily output of single-stream continuous casting machine can reach 3,000 tons, and the multi-stream design
can achieve 10,000-ton capacity, and the automation degree of the production line is more than 90%.
5. Flexible adaptation of product specifications
By replacing the crystallizer and adjusting the process parameters, it can quickly switch to produce billets of
different sections (150mm² to 300mm thick slabs) to meet diversified market demands.
Direction of technological evolution of continuous casting process
With the promotion of intelligent manufacturing and green production concept, continuous casting technology
continues to efficient and refined development:
- Dynamic light under pressure technology
Through real-time monitoring of the billet solidification state, automatically adjust the roller seam pressure,
effectively improve the center segregation and enhance the internal quality of thick slabs.
- Electromagnetic stirring system
Applying rotating magnetic field in the crystallizer and the second cooling zone to refine the grain size and
increase the product strength by 10%-15%, which is especially suitable for bearing steel, wheel steel and
other special steel grades.
- Intelligent Control System
The process parameter optimization model based on Internet of Things can predict and adjust the key indexes
such as steel superheat and cooling rate to control the billet breakage rate below 0.5%.
- Near final shape continuous casting technology
Development of thin strip continuous casting, shaped billet continuous casting and other processes, so that
the shape of the billet is closer to the final product, reduce the subsequent rolling process, reduce
processing costs up to 20%.
Continuous casting process challenges and future trends
Although continuous casting technology has been highly mature, the industry is still facing many technical bottlenecks:
High-end steel production limitations
Part of high-alloy steel, stainless steel due to the complex solidification characteristics, continuous casting
process is prone to surface cracks, the need to develop a special protective slag and cooling strategy.
Equipment large-scale control problems
Ultra-wide thick slab continuous casting machine roll precision needs to be controlled within ± 0.1mm,
the equipment manufacturing and maintenance put forward higher requirements.
Technology upgrade under the pressure of environmental protection
How to further reduce water consumption, recovery of waste heat, realize zero-emission production,
become an important direction of technology iteration.
In the future, continuous casting process will be deeply integrated into the industry 4.0 system:
Digital twin technology to realize the whole process virtual debugging
Artificial intelligence algorithms to optimize the combination of process parameters
Hydrogen steelmaking and continuous casting coupling application
Conclusion
As the cornerstone technology of the modern steel industry, continuous casting process innovation not
only promotes the transformation of steel products from “large quantity” to “high quality”, but also sets
up an industry benchmark in terms of resource saving and environmental protection. With the breakthrough
of new materials and equipment, this technology, which was born in the 1950s, will surely take on a new
vitality in the era of intelligent manufacturing, and provide core support for the global manufacturing
industry to upgrade.