The world's first 3-strand slab caster was put into operation at the Chinese steel manufacturer Tangshan Donghua. (Photo: Primetals Technologies)
In September 2023, Primetals Technologies successfully commissioned the world's inaugural 3-strand continuous slab caster at the Tangshan Donghua Iron and Steel Enterprise Group facility in Tangshan, Hebei province, China. This particular caster was part of a series of six machines initiated by Primetals Technologies during that month.
The innovative 3-strand solution brings numerous advantages to Tangshan Donghua. In comparison to the traditional approach involving two 2-strand continuous casters, the 3-strand slab caster occupies only half the space. Furthermore, the implementation of the 3-strand caster leads to cost-effectiveness in terms of both capital expenditures (CAPEX) and operating expenditures (OPEX). The reduction in CAPEX is achieved through decreased spending on equipment and civil works, while the efficient configuration of the 3-strand caster contributes to lower operational and maintenance costs.
The 3-strand caster introduces cutting-edge technology that elevates the casting process to unprecedented levels. The custom-designed, large tundish has garnered praise from Tangshan Donghua for its rigidity and its ability to optimize the flow of liquid steel. Smart Molds, designed in a straight cassette format, ensure an ideal primary solidification of the strand.
The DynaFlex hydraulic oscillator can adapt the mold-oscillation parameters based on the composition of the liquid steel, resulting in enhanced surface quality of the slabs. As part of the secondary cooling process, the DynaJet spray cooling system ensures a uniform temperature distribution, preventing corner cracks—particularly crucial when casting advanced steel grades.
The 3-strand caster is equipped with a state-of-the-art automation package. Dynamic secondary cooling and soft reduction packages, including DynaPhase, Dynacs 3D, and DynaGap Soft Reduction 3D, significantly enhance the continuous casting process by monitoring various parameters such as thermodynamic effects, online chemical composition, and phase transitions. Moreover, the Level 2 packages offer offline simulation capabilities for the development of new and more efficient casting practices. LevCon, an automatic mold-level control system with "autostart" casting functions and auto-adaptive dynamic bulging compensation, and Mold Expert, which monitors the mold in real-time to prevent breakouts, are integral components of this comprehensive automation suite.
Tangshan Donghua, established in 2009 and ranked among China's top 500 enterprises, operates across diverse sectors, including sintering, ironmaking, steelmaking, hot rolling, and bar and high-end wire-rod rolling. The collaboration between Primetals Technologies and Tangshan Donghua dates back to 2017, focusing on projects related to metallurgical services and offline maintenance for the steel producer's continuous casting machines.
Key facts: 3-strand slab caster at Tangshan Donghua
Radius: 8 meters
Metallurgical length: 40 meters
Thickness of slabs: 210 millimeters
Width range of slabs: 750 to 1,100 millimeters
Casting speed: up to 2.5 meters per minute
Key facts: Expert systems implemented at Donghua’s slab caster
Several expert systems will be implemented at this slab caster:
Nozzle Expert checks the condition of the secondary cooling system and detects any clogged nozzles and leakages with high accuracy.
Quality Expert tracks, controls, and supervises quality-related data and quality prediction for the cast products.
Speed Expert calculates the optimal casting speed in any casting situation while considering factors like superheat and heat pacing.
Yield Expert is a cut-length optimization system that considers scrap portions, quality-related inconsistencies, weight restrictions, and width changes to minimize scrap and optimize yield.