In fusion welding processes, metallic materials of dissimilar type, nature or properties are joined in order to develop a single part with new functionalities. However, during the cooling process, the solidification stage leads to the development of particular material defects inside the weld bead depending from process parameters [Wel01, Kou02]. A thin liquid metal layer may persist between grains and dendrite arms in the coherent grain structure which endure large thermal stresses. This phenomenon promotes the development of hot cracking defects. Similarly, at the same ending solidification stage, the formation of intermetallic brittle phases is commonly observed induced by the complex nature of segregation phenomena. These specific welding defects have to be carefully monitored regarding the expected high level of reliability, mechanical strength and fatigue life intended by industries. This control is particularly evident considering the safety of welded equipment in automotive, aircraft or energy industries. The development of defects is also made worse with the recent use of advanced materials, innovative processes or complex geometries. These defects and theirs consequences are barriers to the efficiency of welding processes to meet future expectations of industries. The NEMESIS project aims to deliver a generalized approach to remove these barriers through the use of virtual materials in a collaborative partnership balanced between modelling, experimentation and valorization. The NEMESIS project will first propose a reliable modelling of grain growth development in welding and associate defect occurrences considering the complex physical phenomena taking place during the whole fusion process. In-situ experimental observations on test benches will investigate grain growth and hot cracking mechanisms (ICB, LMGC) to analyse local criteria leading to defects development. Simultaneously grain structure and associated defects will be modelled in a multi-physics approach (ARMINES-CEMEF) based on the Cellular Automaton-Finite Element (CAFE) approach. Modelling of grain growth at the mesoscopic scale will be coupled with the resolution of the conservation equations at the macroscopic scale in a multiscale approach taking into account thermomechanical, solute and fluid flow evolutions. The CAFE tool will offer the possibility to develop realistic virtual microstructure similar to the ones observed by industries. In addition, the current ultrasonic Non Destructive Testing (NDT) used to detect, localize and estimate welding defects will benefit from this project. Indeed the simulated microstructure and defect morphology obtained from the numerical simulation of welding will be used as input of the ultrasonic inspection simulation codes: the CIVA Software (CEA LIST) and the ATHENA Code (EDF R&D). Defect echoes will be simulated on the numerical material also considering ultrasonic interactions with grains which has large consequence on NDT performances. The effects of the weld microstructure and cracks morphology position, shape or orientation on the inspection reliability will be investigated. Influences of intermetallic phases on ultrasonic interaction will also be a point of interest. The model validation will be conducted on steel grades in industrial configurations. Thus the solidification microstructure and hot cracking formation in welded equipment will be investigated. Nuclear power plant (EDF R&D) and development of brittle phase on automotive steels strengthened with manganese (ArcelorMittal) will be considered. Softwares modelling welding processes (TRANSWELD) and control of defects (CIVA, ATHENA) will benefit from this research and promote the outcomes of NEMESIS. This project corresponds to a significant breakthrough in the mastering and control of arc welding defects through the use of virtual materials and an undeniable technological advance in the mastery of welding processes as a response to industrial needs.

In order to reduce the CO2 emission of their cars from currently 130 g/km to 95 g/km before 2020, car makers are looking for new innovative lightening solutions. A wide use of boron quenchable steels is seen as a very attractive one. Thanks to their very high mechanical properties, they offer opportunities for reducing thicknesses for structural parts by improving the cars’ safety and crash behaviour. The use of quenchable boron steels is therefore today in expansion and the huge majority of car makers are already implementing them on their new vehicles and body in white concepts. Nevertheless the use of these quenchable steels is limited because of process capabilities limits. The corresponding thermo-mechanical forming process, named hot stamping, is based on a fast quenching of the blank in the forming tool right after a forming step at high temperature. This fast quenching induces a metallurgical transformation of the steel which confers very high mechanical characteristics to the formed part. So hot stamping combines good formability properties of steel at high temperature and very high in-use properties of the final part. Nevertheless, parts produced with this process have limited geometrical complexity because no further forming step is possible after quenching. So all the forming has to be done in one and only one operation. Hot stamping costs are also a limiting parameter for car makers because of the high amount of investment needed and because of a production rate limited to a very few parts per minute (3 in average), which means that the amortization of the equipments has a strong impact on the part’s cost. This project aims at permitting the hot stamping of complex shape parts by the development of the scientific and technological knowledge to deserve the design of an integrated progressive die for hot stamping. Progressive stamping, widely used in cold stamping, combines high productivity and the possibility to make very complex shape parts. Its development for hot stamping will open new lightening opportunities and part integration possibilities for car designers thanks to the enlargement of high strength part designs. Thanks to this tool, a whole production line (blanking press, furnace, press, laser cutting) which is currently needed will be replaced by a unique tool under a unique press. This innovative tool will decrease the cost of quenched parts thanks to a reduction of the amount of investment and an increase of productivity up to 10 parts per minute (today’s productivity : 3 parts per minute) . Progressive stamping consists in forming a part with several successive cutting and forming operations done with the same tool. Its development for hot stamping will necessitate the integration of some very attractive and innovative technologies (fast heating, hot cutting) to be able to hang together several operations in adapted thermo-mechanical conditions. More, due to the specificity of this process, the quenching step will have to be managed in a particular way in comparison with the standard one. The behaviour of existing quenchable steels and of their coatings will have to be checked in such conditions. To successfully achieve this project, cooperation between a steelmaker (ArcelorMittal), a stamping tool maker (SMP), a specialist of electrical generators and heating devices (SREM Technologies), a laboratory working on tool wear (ICA) and a laboratory specialised in forming and multiphysics modelling (LIMATB-Université de Bretagne-Sud (UBS)) will take place. Its success is insured by previous and on-going collaborations between these partners. The main force of this project is to be at the heart of today’s automotive world challenges and to give a pragmatic answer to two of the most key issues: the production cost reduction and the lightening of bodies in white, by developing a practical process solution.

3D project aims mainly at demonstrating DMXTM CO2 Capture technology in AMF’s Dunkirk (FR) steel mill on an industrial pilot plant (0.5 tCO2/hr.), bringing TRL from 4 to 7, with 76% of requested EU budget (14,8M€). DMXTM will give Europe an edge in cost, environmental- and energy-efficient recovery of CO2. Downstream requirements are fully considered in studies of conditioning, transport and storage in North Sea aquifers. Waste Heat Recovery well combined with DMXTM process will allow reaching unprecedent CO2 Capture cost under 40 €/tCO2. Environmental, societal and stakeholder’s expectations are dealt from the beginning and all-along the project to ensure capability of deploying the CCS cluster on Dunkirk territory. DMXB solvent production will be optimised industrially and environmentally, through LCA. 3D project is based on an EU holistic approach, building on previous an on-going CCS projects where many 3D partners are involved. 2025 full-scale CCS plant of 1 Mt CO2/y will be implemented from end of 3D project which will be an embryo of the future CCS cluster Dunkirk-North Sea 2035 (10 MtCO2/y). It is a major step in the transformation of energy- and CO2-intensive industries such as steel towards EU targets, with opportunities of job creation all along the CO2 CCS chain, notably for Dunkirk region economies and EU storage Hubs. 3D RTD and engineering providers would develop new markets aside from existing Oil & Gas, smoothing environmental and energy-depletion transition. Furthermore, quality of recovered CO2 through DMXTM process is compatible with food-grade markets. The project success relies on of a highly skilled and experienced consortium involving the complete chain of CCS and key transversal skills (LCA, SSH, KPI/TRL/cost assessment). 11 complementary partners from 6 European countries, of 2 academics (ETHZ, DTU), 4 technology providers (AP, GASSCO, IFPEN, UETIKON), 3 engineering companies (AXENS, John Cockerill, BREVIK), 2 end-users (AMF, TotalEnergies OneTech).