ECCC and ESTAD 2017

The 9th ECCC (European Continuous Casting Conference) and the 3rd ESTAD (European Steel Technology and Application Days) will take place in Vienna from June 26 to June 29, 2017.

The ECCC is a unique forum for the European continuous casting community to exchange views on the status and future development of the continuous casting process. The conference program is abreast of the latest developments in control and automation, advanced continuous casting technologies and the continuing improvement of product quality. Steel metallurgical issues will be addressed as their physical and numerical simulation. The exchange of experience in operational practise, maintenance and first results from recently commissioned plants will complement the program. The conference aims to stimulate the communication among delegates with industrial and academic background and among participants in former conferences and new members of the continuous casting community. To see more, go to eccc2017.org

The ESTAD international conference focuses on the latest trends and issues and provides a wide networking and information platform for equipment and service suppliers, plant manufacturers and steelmakers. At this event you will acquire the latest information on new ideas and developments as well as on the state-of-the-art in metallurgical process technologies for iron and steel production, steel materials and steel application. To see more, go to estad2017.org

Vesuvius is sponsor of the event and will have a booth in the main hall. Visit us! 

Also, 4 papers will be presented by Vesuvius or our customers. Don't miss them!

Paper 1: Refractory design and process optimization in Tata^® CSP Caster

Main authors: Hitesh Hamukhrai SHAH (Tata Steel) and Johan Richaud (Vesuvius)

Summary: Technical solutions and design optimization for better quality, increased productivity and yield have been continuously introduced and implemented in Tata Steel thin slab plant located in Jamshedpur – India to further improve competitive edge in the current steel market. Extensive advanced computer simulations and physical simulations have been conducted to determine the different parameters characterizing both tundish and mold flow. Reduction of dead and cold steel volume, improved inclusion floatation and turbulence reduction in the impact region have been obtained after optimizing the internal tundish geometry. With the new tundish internal geometry, the tundish skull weight has been reduced by 20% with out any quality issues. Addition of tundish gas bubbling device aka TGD is introduced, installed & under evaluation to achieve the reduction of process issues. The new Sub-Entry Nozzle is used to produce stable meniscus flow and optimal mold temperature distribution for flow rate at around 11% higher Thpt than current design & it is planned to increase thpt by further 15% by further study.

Paper 2: Ladle purging versus Tundish purging during casting for enhanced inclusion removal efficiency

Main authors: Ravishekar KONANGI (JSW Vijayanagar) and Johan Richaud (Vesuvius)

Summary: Non-metallic large inclusions are detrimental to most physical and chemical properties of steel and require a removal treatment. Inclusions can provide crack nucleation sites, surface defects, corrosion sensitivity and will reduce mechanical properties. Gas stirring in the ladle is commonly used in secondary steelmaking to homogenize chemical composition of alloy elements and temperature and to promote inclusion floatation. Ladle bottom gas bubbling is effective in removing none wetted inclusions by two main mechanisms. By the collision and adhesion mechanism, the inclusions will attach to the gas bubbles and rise with them and float up with them with higher velocity than an inclusion alone. Secondly the buoyant plume created by gas bubbles will generate recirculation flow patterns in the ladle, which enhances turbulent mixing to homogenize the chemical composition and temperature, and helps to accumulate and drag and direct the inclusions to the top slag layer and then to be removed. For the inclusion floatation, a relatively low inert gas flowrate is necessary to prevent breaking the ladle slag layer. In JSW Vijayanagar steel plant, in addition to the gas injection during the secondary metallurgy, ladle purging has been also evaluated during the teeming of the vessel. Numerical simulations have been conducted to determine the best location(s) of the purging plug(s) for optimal deoxidation inclusion floatation. The required gas flow rate has been computed in relation to the remaining steel weight. In parallel, gas injection inside the tundish has been assessed and the removal efficiency of de-oxidation + re-oxidation related inclusions has been compared with the ladle and the results presented in this article.

Paper 3: Tundish flow optimization in Aperam Genk for quality improvement

Main authors: Bastien Soete (Aperam Genk) and Christian Warmers (Vesuvius)

Summary: The decrease of first slabs downgrades and the reduction of clogging on specific alloyed steel grades to increase product quality and extend casting sequence have been one of the priorities of Aperam Genk continuous casting team. High steel quality levels and particularly cleanliness have to be achieved at the beginning of the cast. Tundish filling has been studied along with the influence of the different refractory product geometry on turbulence generation and air entrapment. Ladle shroud position and verticality, Turbostop® design, tundish outlet geometry including stopper nose and casting channel entrance have been evaluated using advanced numerical simulations. These refractory parts have been redesigned to enhance tundish flow performance in regards to NMI floatation, cold steel volume reduction, minimum residence time increase, turbulence reduction during steady operations and during the initial tundish filling.

Paper 4: Mold Level Scanning, a new tool to characterize steel flows in mold

Main author: Maïté Cornille (Arcelor Mittal Maizières Research) and support of Michel Dussud (Vesuvius)

Summary: Steel meniscus fluctuations and level deformations in CC mold are one cause of the defect occurrence on slabs and later on coils. Slivers, which are one of the most costly defects observed on coils, are partly due to slag entrapment in CC mold. Actually, a strongly deformed meniscus and sudden meniscus level fluctuations favor the slag carry-away into the steel and entrapment of slag droplets in the solidifying shell in mold. Process parameters (such as mold width, casting speed, argon flow rate …) or events (such as clogging, breakout alarms …) impact directly steel flows in mold through the meniscus velocity and the flow pattern but through the meniscus deformation and steel level fluctuations as well. Following these last data would enable to better understand what happens in the mold and to act efficiently to improve the product quality. ArcelorMittal Research and Vesuvius developed a tool to measure on-line the steel level along half of the mold width. The device is composed of a robotized manipulator arm which insures the translation/rotation movements of an Eddy-current head, similar to the one used for mold level control. The first prototype was installed on an ArcelorMittal caster. The equipment is fixed on the tundish car and can operate just after the sequence start-up.

Measurement campaigns showed the impact of casting parameters on the meniscus deformation. Position of “waves” actually depends on the mold width and the casting speed. It was also noticed that the intensity of level fluctuations is not constant during casting even if the process parameters are kept constant. This equipment is therefore an interesting and relevant tool to better control the casting process and drastically reduce the mold slag carry-away at meniscus, which could be at origin of many defects such as slivers.