Process Metallurgy group

Melting and remelting processes

For around 30 years, the group has been known as an international academic leader in the field of melting and remelting of various metallic alloys (titanium, zirconium, maraging steel, Ni-based superalloys), in particular in modelling of refining processes to help optimization of the units. Vacuum arc remelting (VAR), electro-slag refining (ESR), electron beam melting (EBM), vacuum arc skull melting (VASM), and plasma arc melting with cold hearth refining (PAM-CHR) have been the object of many PhD studies in collaboration with the industry (Eramet, Safran, Timet Savoie, Framatome and Aperam).

Permanent staff:

Alain Jardy, Jean-Pierre Bellot, Pierre Chapelle, Thibault Quatravaux

Conferences:

Liquid Metal Processing and Casting LMPC, every 2 years, alternatively in Europe and the US.

Thesis:

Running in 2020, 5 PhDs under CIFRE conventions with industrial partners and 1 post-doc internship, Léa Décultot, Rayan Bhar, Jérémy Chaulet, Jérémie Haag, Thomas Poullain, Julien Banos

Articles:

• On the modelling of thermal radiation at the top surface of a vacuum arc remelting ingot, Delzant et al., Met. Trans. B 2018, 49, 958-968
   
• A 2D multiphase model of drop behavior during Electroslag Remelting, Chaulet et al., Metals 2020, 10, 490
   

Reduction of CO2 emissions from the steelmaking industry

Nowadays, steelmaking is directly responsible for about 7% of the anthropogenic greenhouse effect in the world. The group investigates various alternatives to the conventional processing route based on blast furnaces and oxygen steelmaking, such as:
- the so-called direct reduction of the iron ore by an H2-CO syngas, to halve CO2 emission;
- the direct reduction of ore by pure H2, which could reduce CO2 emission by 80%;
- a completely new process, the reduction by biomass in a shaft furnace, combined with recycling.

Permanent staff:

Fabrice Patisson, Olivier Mirgaux

Project:

PIA Valorco, 2014-2019

Thesis:

Labex DAMAS 2019-2022, Tao WANG

Articles:

• Detailed modeling of the direct reduction of iron ore in a shaft furnace, Hamadeh et al., Materials 2018, 11, 1865
   
• Carbon impact mitigation of the iron ore direct reduction process through computer-aided optimization and design changes, Béchara et al., Metals 2020, 10, 367

Inclusion behavior in liquid metals

In metallurgical reactors, such as liquid steel treatment ladles or aluminum refining units, physical and chemical reactions lead to an evolution of the inclusion population which is responsible for the cleanness of the final product. CFD simulations at full process scale are combined with local approaches to improve the understanding of interactions at smaller scale: aggregation, deposition, and capture at interfaces.

Permanent staff:

Jean-Pierre Bellot, Jean-Sébastien Kroll-Rabotin, Thibault Quatravaux

Project:

ANR-DFG Flotinc 2016-2019

Thesis:

• CIFRE Affival 2016-2019, Edgar CASTRO CEDENO
• ANR Flotinc 2016-2019, Mathieu GISSELBRECHT
• LabEx DAMAS 2016-2019, Manoj JOISHI

Articles:

• Toward better control of inclusion cleanliness in a gas stirred ladle using multiscale numerical modeling, Bellot et al., Materials 2018, 11, 1179
   
• Numerical simulation of modification of non-metallic inclusions by calcium treatment in the argon-stirred ladle, Castro et al., Met. Res. Tech. 2019, 116

Environmental issues

In order to either reduce the impact of existing processes for the fabrication and treatment of materials on the environment or design new processes, a rigorous approach is required to evaluate the impact. The group has developed an original methodology which associates process systemic modelling and Life Cycle Analysis (LCA) of products, processes, and routes. In this approach, the use of systemic modelling ensures a high quality of the life cycle inventory.
Some recent applications:
- a comparison of biomass-based heat and electricity co-generation processes in terms of energy and environmental impacts;
- the evaluation of several processes for the capture of CO2 originating from a coal-fired plant.

Permanent staff:

Olivier Mirgaux, Fabrice Patisson

Project :

Pacte Lorraine CTSA, 2016-2019

Thesis:

CNRS-Région Grand Est 2016-2019, Hélène ANSELMI

Articles:

• From trees to electricity, the physics beyond the LCA, Mirgaux et al., Matériaux et Techniques 2016, 104-106, 1179
   
• Simulation of post-combustion CO2 capture, a comparison among absorption, adsorption and membranes, Anselmi et al., Chem. Eng. Technol. 2019, 42, 797-804

Vacuum electric arcs

These studies aim at better understanding the phenomena involved in the behavior of electric arcs between metallic electrodes, operating under vacuum, in order to help controlling the devices where such arcs are present. Based on both experiments and numerical simulation, researches are devoted to the characterization of arc regimes, to the analysis of the arc dynamics, and to the modelling of the plasma jets and of arc-electrode interactions. A key feature is the observation and measurement on industrial units.

Permanent staff:

Pierre Chapelle, Alain Jardy

Thesis:

• CIFRE Timet Savoie 2015-2018, Pierre-Olivier DELZANT
• Supergrid Institute 2015-2018, Benoît TEZENAS DU MONTCEL

Articles:

• Numerical study of the current constriction in a vacuum arc at large contact gap, Tezenas du Montcel et al., IEEE Trans. Plasma Sci. 2019, 47, 2765-2774
   
• Investigation of arc dynamics during vacuum arc remelting of a Ti64 alloy using a photodiode based instrumentation, Delzant et al., Jl. Mat. Proc. Tech. 2019, 266, 10-18

Mathematical modelling and numerical simulation

• In-house built software dedicated to process simulation (Solar, Reductor, Flua, DissolFil, etc.)
• Finite volume method for the solution of liquid or gas flows and coupled transfers
• Lattice-Boltzmann and immersed boundary methods for the modelling of inclusion behavior
• Developments on commercial or open-source software – Ansys Fluent, Comsol, OpenFoam, Aspen Plus, GaBi, Factsage

Liquid metal processing

• Vacuum Induction Melting 50 kW furnace fully equipped for the melting of metals and alloys up to 1650 °C. Possible use of a graphite susceptor
• Cold Crucible Induction device (200 kW) for the melting of reactive metals (Ti, Zr) or the liquid treatment avoiding contact with a refractory crucible
• Laboratory-scale Electron Beam Melting furnace (1 EB gun, maximal power 100 kW) operating under high vacuum (10-5 - 10-4 mbar) and equipped with a small ingot casting facility, (up to 100 mm in diameter) suitable for drip-melting or cold hearth operation

Gas/solid reactions

• Park of thermobalances for thermogravimetry experiments (from the room temperature up to 2400 °C) under inert or reactive gases such as H2, CO2, CO, H2O
• Differential Thermal Analysis

Physical and chemical characterization

• Gas chromatography
• Mass spectrometry
• Fourier Transformation Infra-Red (FTIR) absorption spectroscopy
• Carbon/Sulphur analysis in solid compounds (from 1 ppm to 100%)
• Glow discharge optical spectroscopy
• Sieverts’ technique
• High definition and high speed videocamera
• Infrared thermography

Technology transfer

• In 2018, creation - by a former post-doctoral fellow - of the start-up O2M Solutions, specialized in high performance computing, process simulation and OpenFOAM®

CNRS researchers

• Pierre CHAPELLE

Professors, assistant professors

• Jean-Pierre BELLOT
• Jean-Sébastien KROLL-RABOTIN
• Olivier MIRGAUX

Tenure tracks

• Thibault QUATRAVAUX
• Isnaldi RODRIGUES DE SOUZA FILHO

Technical and support staff

• Julien JOURDAN
• Jean-Baptiste LETZ
• Jonathan MARTENS

PhD students

• Widad AYADH
• Hamid BELLACHE
• Rabeb BEN HASSINE
• Antoine MARSIGNY
• Nicolas STANKOVIC
• Hervé STROZYK

Post-doctoral researchers

• Svetlana TSAREVA

Emeritus

• Fabrice PATISSON