40 research outputs found

    STRESS CORROSION CRACKING OF A TRIP STEEL

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    Net-Zero transition in the steel sector: beyond the simple emphasis on hydrogen, did we miss anything?

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    There is an explosion of publications and of various announcements regarding the use of hydrogen in the steel sector as a way to arrive at Net-Zero steel production − particularly in Europe. Most of them describe process technologies on the one hand and commitment to implement them quickly in the steel sector in the form of roadmaps and agendas, on the other hand. The most popular process technology is H2 Direct Reduction (H2-DR) in a shaft furnace. Available technical literature, as abundant as it may be, is still fairly incomplete in making the pathway to Net-Zero explicit and credible. This paper tries to identify important issues which are not openly discussed nor analyzed in the literature, yet. Process-wise, open questions in technical papers are: (1) what are the best-fitted iron ores for H2-DR, (2) what downstream furnace, after H2-DR, can accommodate various raw materials, (3) how and how much carbon ought to be fed into the process, (4) what is the best design for the shaft, (5) should it be designed for both natural gas and H2 operations, or simply for H2, (6) how should the progress of R&D be organized from pilot plants up to full-scale FOAK plants and then to a broad dissemination of the technology, (7) what kind of refractories should be implemented in the various new reactors being imagined, etc. Cost issues are also widely open, as a function of green hydrogen, green electricity and carbon prices. How is hydrogen fed to the steel mill and what exactly is the connection to renewable electricity? Is the infrastructure that this calls for planned in sufficiently details? What is still missing is a full value chain picture and planning from mining to steel mills, including electricity and hydrogen grids. Two years after our last review paper on hydrogen, the overall picture has changed significantly. Countries beyond Europe, including China, have come up with roadmaps and plans to become net-zero by 2050, plus or minus 10 years. However, they do not rely as much on H2 alone, as Europe seems to be doing. What is most likely is that several process routes will develop in parallel, including, beyond H2-DR, Blast Furnace ironmaking and NG Direct Reduction with CCS, electrolysis of iron ore and scrap-based production in EAFs fed with green electricity, which would single-handedly support the largest part of production by the end of the century; as more and more scrap is to become available and be actually used. There is also a question for historians. The influence of Climate Change on Steel has been discussed continuously for more than 30 years. Why has the commitment to practical answers only solidified recently

    Palimpsest and heterotopia, metaphors of the Circular Economy

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    Words like palimpsest or heterotopia do not belong to the working vocabulary of materials or engineering sciences: they are used in Social Sciences and Humanities (SSH). A palimpsest is a manuscript written on an older document, the text of which has been erased. Heterotopia is a young word forged by Michel Foucault in 1967 to describe a closed space, the boundaries of which mark a discontinuity in terms of behavior: a jail or a monastery are thus a heterotopia. The Circular Economy (CE) is an essential concept in the framework of the ecological transition, pulled by a series of converging economic, ecological and political drivers. It is usually described as the adoption of a circular model of production to replace the “linear model”, but also as the new buzzword to describe material efficiency, the 3-R rule, the zero-waste ideal, the concepts of lean or frugal design or their reformulation by the Ellen Macarthur Foundation, as a societal challenge and an ethical necessity. Materials producers claim that they have been practicing the Circular Economy since long before the expression was ever invented, thus à la Monsieur Jourdain, etc. The point of this paper is to describe the Circular Economy as a palimpsest and as a heterotopia and to use the metaphors, if indeed they are only metaphors, to highlight some of the less obvious features of the CE. A palimpsest is a parchment or a papyrus, which is used several times to support a series of consecutive texts. Secondary raw materials are like a palimpsest, because there are retrieved from a previous life and used again in a second life: a new artefact made from that material is like a new text written on/with this material – a metaphor also used, mutatis mutandis, in expressions like 3-D printing or laser scribing. Some interesting features of the CE pointed out by the metaphor: a the palimpsest can be used several times, like a material can be recycled several times; the concept of the palimpsest posits that the parchment is somehow more important than the text that is written on it, therefore a material is more important than the goods that are made of it; the palimpsest was used before the invention of paper and, similarly, the Circular Economy was the standard model before mass production of cheap consumer goods imposed the so-called “linear model”; a palimpsest keeps a fragmented memory of the past, in the same way as recycled material maintains a link to its past lives, through its composition in tramp elements. Examples of heterotopia are a prison or a cemetery. The Circular Economy defines a space where a particular material/element exists in its various avatars, impersonations and reincarnations and this may tentatively be worked out as a heterotopia. This is a more complex endeavor than discussing the palimpsest metaphor, but a potentially more fruitful one. Foucault has provided criteria defining heterotopia which can help us explore the analogy: particularly the point that such a space is either a space of illusion or a space of perfection. This analysis is original because it hybridizes materials and SSH concepts and thus fits with the exploration of the frontier between materials and society that SAM conferences are concerned about

    What is the connection between metallurgy and environmental issues? Could a new discipline emerge from this confrontation?

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    In neoclassical economics, the environment is an externality and environmental issues are treated as an add-on feature. In metallurgy, the environment is handled in a similar way, for similar reasons: environmental issues are both external to the core themes of metallurgy and to the economics of process metallurgy. Environmental issues range from corrosion, to generation of by-products, to air and water emissions, to environmental footprints (carbon footprint, water footprint, etc.), a measure of the burdens/liabilities that metals production and use impose on the “planet”, to social footprint, a measure of the assets brought about by the economic activities they generate, and to recycling, re-use and nega-use issues

    How to tell the story of change and transition of the energy, ecological and societal systems

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    After overusing the expression Sustainable Development, some action plan was needed to switch from rhetorical to transformational change. One of the answers was to propose the word Transition as a roadmap leading to the necessary level of change. A Transition is a passage from one stable regime to another, with a step that is neither instantaneous nor dangerous, like a Revolution, but is fast enough, anyway. The first Transition in the 2010s was the Energy Transition, i.e. a move towards less fossil fuels and more renewables. It started everywhere more or less at the same time, but Germany and its Energiewende was among the first contenders. The implicit objective was as much to control excessive anthropogenic GHG emissions as it was to possibly start a new period of growth based on green technologies. Very soon, however, the Fukushima disaster convinced Mrs. Merkel to change tack and veer towards “zero nuclear power”, thus aligning with the program of the Green movements. At that point, the Energiewende had become a complex, multi-objectives program for change, not a simple Transition as described at the onset of the paper. The rest of the world turned to Globish and spoke of the Energy Transition (EnT). Each country added a layer of complexity to its own version of the EnT and told a series of narratives, quite different from each other. This is analyzed in the present article on the basis of the documents prepared by the “energy-community”, which assembles hard scientists and economists, a group that the soft scientists of SSH call STEM. EnT, in its most recent and mature version, hardly speaks of energy any more but of GHG emissions. Therefore, EnT drifted towards the expression Ecological Transition (EcT). Both expressions are almost synonymous today. From then on, myriads similar expressions sprang up: Environmental Transition, Demographic, Epidemiological and Environmental Risk Transition, Societal Transitions, Global Transitions, Economic Transition, Sustainability Transition, Socio-Ecological Transitions, Technology Transitions, Nutrition Transition, Agro-Ecological Transition, Digital Transition, Sanitary Transition as well as various practices like Energy Democracy or Theory of Transition. Focusing only on EnT and EcT, a first step consists in comparing energy technologies from the standpoint of their impact on public health: thus, coal is 2 or 3 orders of magnitude worse than renewable energy, not to speak of nuclear. A second step looks at the materials requirement of Renewables, what has been called the materials paradox. They are more materials-intensive and also call on much larger TMRs (Total Materials Requirement). On the other hand, the matter of critical materials has been blown out of proportion and is probably less out of control than initially depicted. A third step is accomplished by Historians, who show that History is full of energy transitions, which did not always go in one direction and did not always match the storytelling of progress that the present EnT is heavily relying on. Moreover, they flatly reject the long-term storytelling of History depicted as a continuous string of energy transitions, from biomass, to coal, oil, gas, nuclear and nowadays renewables. Just as interesting is the opinion of the Energy-SSH community. They complain that the organizations that control research funds and decision makers listen mainly to the STEM-energy community rather than to them. And they go on to explain, sometimes demonstrate, that this restricts the perspective, over-focuses on certain technologies and confines SSH to an ancillary role in support of projects, the strategy of which is decided without their input: the keyword is asymmetry of information, which therefore leads to distortion of decision-making. They also stress the need for a plurality of views and interpretations, a possible solution to the societal deadlocks often encountered in Europe. As important and strategic as energy issues are in our present world, the hubris of both STEM and SSH communities may be excessive. Some level of success in making them work together may be a way to resolve this situation

    The environment and materials, from the standpoints of ethics, social sciences, law and politics

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    Materials are deeply connected with the environment, because they stem from raw materials extracted from the geosphere, rely on large amounts of energy and of water in their production stage, project emissions to air, water and soil when their ores (or minerals) are mined, when they are made in steel mills or cement kilns, including very significant amounts of greenhouse gases. They also contribute to emissions and energy consumption of the artifacts of which they are part, either consumption or investment goods. Their connection with the biosphere raises many issues, in terms of toxicology, ecotoxicology or biodiversity or simply of public health or in the working place. Materials, as an essential part of the anthroposphere, interact deeply with the anthroposphere itself but also with the biosphere, the geosphere, the atmosphere and the hydrosphere, thus with nature in a general way through mechanisms which can no longer simply be described at the margin, as resource depletion or as pollution. This raises issues related to the sustainability of materials in human activities, in which they are deeply immersed and entangled. The standard way of dealing with these environmental issues is to invoke sustainability and to explain that all actors are engaged in sustainable development, a morals or an ethics that points in which direction to go: all players in the materials field, industry, institutions and research, claim allegiance to sustainable development. At a more technical level, specific tools like Life Cycle Assessment (LCA) are used extensively to measure the interaction of materials with the environment. This, however, is not enough to deal properly with the environmental issues of materials, because these issues are not marginal any longer: the anthroposphere has become so large with respect to the biosphere, the geosphere and the planet in general that environmental risk is now part of modern life, especially in connection with climate change and the loss of biodiversity. To go deeper in analyzing the connection of human activities with nature, it is therefore necessary to reach out to SSH (Social Science and Humanities) disciplines and particularly to environmental ethics. This is a prerequisite for materials scientists (and others) to act decisively in the future in the face of the danger that lies ahead of us. The present paper reviews the advances of environmental ethics, a fairly young discipline born in the 1970s, in as far as it can help all actors on the world anthropospheric theater choose their lines for the future in a more conscious and sophisticated way than simply claiming obedience to sustainability. We will review briefly intellectual forerunners of the discipline like Jean-Jacques Rousseau, Henri David Thoreau, Rachel Carson or Paul Ehrlich. This will help flesh out well-known concepts like the precautionary principle or the “polluter-pays” principle, which are invoked in creating new materials or new processes to keep pollution and health issues under control, as part of the constraints of professional ethics but also of environmental law. It will be necessary to question to whom or to what the key concept of intrinsic value is attached: people, all living organisms or ecosystems, i.e. the environment in general, and thus to define anthropocentrism, biocentrism and ecocentrism. Environmental law and the ethics of sustainable development are still mainly anthropocentric while scientific ecology is more clearly ecocentric. To tackle the challenges of environmental issues as they are posed today and to avoid catastrophes, it might be necessary in the future for all social players and for people of the world of materials to follow the steps of environmental ethics and to move up from anthropocentrism to the broader vision of ecocentrism
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