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CORDIS - Résultats de la recherche de l’UE

Advanced THermomechanical mOdelling of Refractory linings

Periodic Reporting for period 2 - ATHOR (Advanced THermomechanical mOdelling of Refractory linings)

Période du rapport: 2019-10-01 au 2022-03-31

Research carried out in the ATHOR project has contributed to the advancement of our knowledge of refractory materials. Refractories are heat-resistant materials used as inner linings of high temperature furnaces, reactors and processing units. As the only low cost material able to sustain operating conditions, at temperatures above 1000°C, refractories are used to contain and process fluids, such as molten metal and glass. Due to the harsh working environment, a constant re-engineering of refractories is needed, making R+D in the sector vital. Refractories are directly related to the competitiveness of European steel companies and the development of major economic sectors, the impact of any innovation will be felt across Europe.
Through the adaptation and development of the most advanced modelling strategies and experimental technologies, reliable computations and measurements have been achieved at high temperature. Refractory materials used in the lining of a steel ladle, operate in the temperature range 1200-1600oC. ATHOR has targeted the development of high-end engineering technologies in the fields of material’s science and numerical simulations to make a substantial contribution through the design of more robust and reliable refractory linings. Ultimately, the aim has been to reduce refractory costs, increase the equipment’s availability and enhance the process control. In addition to meeting our industrial partner’s interests, through the reduction in energy use, ATHOR has also contributed to tackling environmental issues.
Refractories used in a steel ladle require a wide range of properties, e.g. high thermal stability, high erosion resistance, high corrosion resistance, penetration resistance, thermomechanical stability, impact resistance, flexibility and creep resistance. The constant re-engineering required by the ladle permits analyse of refractories under real world conditions and direct application of the results. The steel ladle was thus chosen as the focus of ATHOR.
From refractory producers to end users, all sections of the refractories value chain have benefitted from the research carried out during the ATHOR project.
New measurement tools have been developed and applied to specific experimental devices: ATHORNA, bi-axial high temperature press and a 3D pilot steel ladle. These were used to validate, at mesoscopic level, the results of numerical modelling based on new mathematical and numerical methods taking into account mesoscopic materials and contact properties. These measurement tools and models will continue to be exploited by both the industrial and academic partners.
A large database generated from the advanced characterisation of raw materials used in refractories manufacture has been developed. This will remain available to the project partners for future use.
Optimisation of industrial devices will be made possible through future simulations of industrial problems. In order to obtain data for the validation of advanced analysis methods, refractory masonries were characterized experimentally under different complex conditions. A large and comprehensive experimental campaign was implemented, wallets were constructed and subjected to uniaxial and biaxial loading from room temperature to high temperature. A 3D pilot steel ladle was designed, constructed and tested. These investigated 3D pilot and full-scale models have provided unique and valuable information for the calibration and validation of the developed numerical macro-models and will continue to be exploited by our partners.
Dissemination of the results has taken place via participation in conferences in Japan, China, America and Europe and publications in Rank A journals such as the Journal of the European Ceramic Society, Ceramics International and the International Journal of Mechanical Sciences. These published results are openly available via the ATHOR website.
The research was organised into scientific work packages (WP). The WPs were organised so refractory materials were analysed from the micro to the meso scale. WPs 1 and 2 focus on experimental aspects, WP1 developed measurement tools such that the accuracy achieved is suitable in extreme environments and WP2 characterised raw materials, refractories and joints to develop a database of material properties. WP 3 focussed on innovative systems modelling of industrial systems, fed with data from WP2, from the microstructure to the industrial scale. Finally, WP4 incorporated the measurement tools developed in WP1 to help validate the modelling results obtained in WP3. The progress beyond state of the art is detailed below.
WP1 - Improvement of measurement tools
• Experimental protocols for optical techniques have been optimized and developed for measurements in laboratory furnaces up to 1500°C
• Improvements have been made for optical measurements taking place in extreme environments: high temperature, thermal gradients, measurement stability of devices, large structure size
• Due to differences in laboratory and industrial conditions, the effect of environment at each step has been assessed
• For thermomechanical data interpretations, measured strain fields (obtained by optical techniques) have been correlated to thermal fields (obtained with an infrared camera). Thermocouples with wireless recording were also considered
• Strain gauges at high temperature have been investigated
WP2 - Advanced characterization of raw materials, refractories and joints
• Temperature history for determination of mechanical and thermal properties
• Influence of corrosion on thermal and mechanical properties; especially on the RUL (refractoriness under load) and creep in tension and compression
• Fundamental corrosion mechanisms for selected systems
• Thermal fatigue behaviour for refractories at room and high temperature
• Fracture mechanical testing in the SEM for the clarification of fracture mechanisms on the micro-level
• Inverse evaluation of creep parameters for asymmetric creep out of the Brazilian test by use of FEM-u: DIC coupled with finite-element simulation
WP3 - Innovative modelling approach from microstructure to industrial scale
• Identification of the best model in the literature for the thermomechanical behaviour of refractories, involving the micro to macro scales
• Enhancement of the identified model to add the effect of corrosion
• Identification of the parameters, from raw material to masonry lining, to optimize the design and to improve industrial vessels lifespan
• Use of innovative modelling, such as DEM, able to deal with multi-fractured media
WP4 - Advanced measurements for validation
• The ATHORNA device has been developed to carry out advanced measurements in-situ
• A 3D pilot model of the industrial steel ladle has been developed
• Large-scale testing on conventional masonry, applied to refractory masonry
These continued improvements in refractory linings will have an economic and environmental impact on industries directly and indirectly employing millions of European citizens. With their expertise on modelling and characterization, ESRs have been employed by our industrial partners and will be part of new development activities to reduce cost and time required for the development of new materials and technologies.