Direct Rolling of Continuous Casting Blooming
Blooming is a form of hot rolled material produced from a continuous caster. Hot-rolled blooms are the reduced components of slabs, steel bars, and structural shapes. For many years, blooms have been treated as semifinished parts and directly sent to the rolling plant, subsequently to be processed into hot-rolled products. Nowadays, a process called direct rolling of continuous casting blooms is becoming increasingly popular due to its ‘green’ and economic value.
Direct Rolling is the art of transforming a continuous casting bloom into a hot-rolled semi-finished product in one pass. The direct rolling process conveys the bloom from the caster to the rolling stands and features the advantages of higher efficiencies. The advantages of direct rolling are numerous, such as lower energy consumption, minimal processing wastes, reduced handling times, and drooling effects of the blooms. In addition, the system is reliable and can be overseen remotely at low-cost. A key feature of direct rolling is the cooling curve of the bloom. The bloom cooling process is essential for the control of material flow and for the improvement of rolled product quality. During direct rolling, the cooling process of an ingot-sized bloom has to be designed carefully for optimal results.
In general, direct rolling requires careful consideration of the bloom’s size and shape, casting conditions, geometrical properties, and alloy composition. Besides reinforcing parameters, hot rolling and structural factors of the bloom should be taken into account too to ensure a stable and continuous operation of the direct rolling process.
The direct rolling process can be divided into the following stages: direct rolling of the bloom by applying mechanical forces, instrumentation, and control; bloom cooling during direct rolling to avoid overheating, oxidation, and thermal distortion; and non-destructive testing to ensure quality of the cold-rolled product.
At present, direct rolling is extensively applied in many steel production facilities, as a cost-effective and green process to obtain hot-rolled bloom. Companies specializing in direct rolling services also provide reliable technical support and advice during the whole process. To conclude, direct rolling of continuous casting blooms is an efficient and eco-friendly process for producing semi-finished products with a higher quality compared to the traditional process.
