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Saturday, 22 March 2008

Materials Science and Technology, Feb. 1985, Vol 1- 1st Issue.

Abstract:

Work which has helped to improve vacuum induction melting (VIM) procedures (radically) for alloy 718 is described. Three aspects of melting in a 5Tonne industrial VIM furnace are considered: oxygen control by carbon deoxidation; oxygen and sulphur control by alkaline earth and rare earth additions; and the effect of these additions on melt cleanness, with respect to virgin and remelt charge materials, on both virgin - and remelt-charged heats. Measured and calculated activity coefficients are compared. In the absence of aluminium, good agreement is found between measured and calculated values. The fact that measured activity coefficients for a complex nickel-based superalloy agree well with predictions based on data for dilute iron alloys could indicate that such data may be useful for predicting oxygen behaviour in a wide range of iron based and to some extent nickel-based alloys. A method for evaluating alkaline earth and rare earth additives in relation to bath sulphur content is given, together with the rate law for removal of excess residual additives. The effect of these procedures on inclusion density and morphology is discussed.

Such materials are typically poured into 500mm diam electrodes and remelted by Vacuum Arc Remelting (VAR) or Electro-Slag Remelting (ESR) This is known within the industry as VIM+VAR or VIM +ESR processing.

Naturally all remelted materials were fully analysed and chemically, macro- and micro-structurally and examined. Ultrasonics are typically performed on forged bars. Both virgin & remelt routes were qualified for aero-engine applications - a first within the aeronautic and space-industries.

More information, if necessary, may be obtained upon request.

I would naturally be pleased to hear of evolutions, from raw material prices & melting (increased furnace size & reduction of unit costs) to final applications such as in aero-engines (CFM56, RR, Pratt & Whitney families ...) all possible realisations based upon this and similar work.

Friday, 21 March 2008

Materials Science and Technology Feb. 2008


Metallurgical Modelling

Having wrestled on the shop floor as a metallurgist, products and advanced process engineering, I have come to appreciate, immensely, all manner of metallurgical modelling, mathematical & physical for it's power to reduce; trial & error, scrapped melts & products, extensive end product controls-NDT & DT and last but not least, the associated corporate and "corporal stress levels"!

Typically, advanced process would be: EAF, AIM, VIM,VAR,ESR, Melting for Ultra-clean alloys & powders. These processes are known to respond well to difficult chemical alloy formulations, and stringent quality controls to the highest specifications and client requirements. Equally, the materials would cover a complete spectrum of special steels and alloys, including: Aircraft undercarriage HSLA steels, Iron-Nickels alloys for cryogenic and magnetic applications, Corrosion resistant stainless, 18Cr/10Ni type and higher or the notoriously difficult to heat-treat Fe-Cr , through to Nickel or Cobalt based Superalloys for aeroengine or nuclear applications.

It is with pleasure that I echo IOM3's member subscribed Journal on metallurgical and materials fundamentals Materials Science & Technology published by Maney in Leeds and underline four papers on mathematical modelling:

Mathematical models in materials science pp. 128-136(9) Author: Bhadeshia, H.K.D.H. ant

Integrated modelling in materials and process technology pp. 137-148(12) Author: Hattel, J.H.

Thermodynamic and kinetic modelling: creep resistant materials pp. 149-158(10) Authors: Hald, J.; Korcakova, L.; Danielsen, H.K.; Dahl, K.V.

Nitrogen diffusion and nitrogen depth profiles in expanded austenite: experimental assessment, numerical simulation and role of stress pp. 159-167(9) Authors: Christiansen, T.; Dahl, K.V.; Somers, M.A.J.

I invite you to join me in reading these and the many other available papers and look forward to your comments either in the IOM3 house journals eg. MW "Letters to the Editor" or on my personal blogs. Please do not hesitate to communicate your web-logs, comments and suggestions or to request information on how-to start your own log.

Remember though, "in the days of thy youth", "It's not worth dying for!"

Thanks for your attention.

Call a Spade a Spade - Omit the emissions euphemism

As in "Omit the emissions euphemism" title of
a recent Tim Jarvis' blog-note.

When I read the above referenced post by Tim Jarvis, I was struck by the pertinence of his comments and arguments and shared many of his intuitions gleaned from various reports widely resourced. I felt compelled to draw web-log readers to Tim's work and approaches.

“The first step to addressing the problem of climate change is to use the correct language - pollution, not emissions. The term pollution is logically correct. Moreover, using it immediately shows up some otherwise well-meaning solutions as false, and it prepares the ground for what is really needed: a regulated cap on acceptable levels of pollution.”

where Tim Jervis highlights some major discrepancies in common day language and thought.

“Accepting this word pollution is the first step towards averting long-term climatic disaster. It clarifies the problem and even helps to immediately assess the relative merit of some candidate solutions.Would you like a personal CO2 pollution credit, as advocated by the Royal Society of Arts and echoed by the UK government's David Miliband? No. I don't want personal pollution credits for mercury, lead, CFC or SO2 either. I certainly don't want personal pollution credit cards filling up my wallet.”

“As people in business, we must clean up the pollution for our consumers and pass on our costs through the economy. There is only one great technological fix available at present - the capability to modify power stations to capture the CO2 they produce. Otherwise, the options are limited and unsatisfactory.” [since carbon trade started most countries offered free credits to their major companies – not exactly educational or responsible governance! Refs TBD, all in the name of global competition!]

I have reached similar conclusions, "independently", in a recent literature review which I call synergy-system4: whose focus is on CO2 reduction, based on three pillars of the Institute of Materaial,Minerals & Mines [UK] 1 mines (coal) 2. energy- power plan(coal combustion) 3. metallurgy & materials, as yet unpublished in final form.

He concludes:

“Call CO2 pollution what it is, then regulate it to cap it. Regulate it at source (and at the border of your country if it is not regulated in the country of origin.) Regulate to manage the absolute amount in the atmosphere. This means caps are more important than trades. You don't reduce the number of slaves just by creating an international slave trade. Concentrate on the cap, then the mechanism.”

Thursday, 20 March 2008

Calculation of CO2 in Nuclear Power Plant Construction

If you are looking for some simple but effective calculations to answer such apparently complex question as:

-What is the CO2 pollution from nuclear construction and what is it’s significance? or
-How much CO2 is produced when making the 520,000 cubic meters of concrete and 67,000 tonnes steel needed to make in a 1GW nuclear power station?

Then an excellent place to start is Tim Jarvis’s blog notes. Calculation methods and data sources are clearly stated as are any order of magnitude approximations made.

I strongly recommend the interested reader to visit the above reference and many other posts on Tim's web-log.

Tim's approach naturally caught my attention as a metallurgist, involved in the energy intensive manufacturing of clean steels and special alloys, for many years. Processes involved are often by definition, of the more controllable, electric steelmaking type, whose heat source is totally independent of chemically produced heat, eg. from carbon combustion with oxygen (CO2)or other chemical or metallic additions. High duty high reliability applications would typically include high temperature (creep resistant = slow stretching or flow) corrosion resistant, high strength and toughness aeronautic and nuclear quality grades...

Therefore, I am particularly pleased to reference more widely, sources of CO2 pollution from steelmaking mostly from Tim’s site but also my own questioning leading to a short review from IISI “International Iron & Steel Institute's data.

References
1. Danish Technology Institute report on CO2 in concrete production.

2. Blue Scope Steel

3. Azom Materials suggests around 2 tonnes of CO2 per tonne of steel.

4. Tata Steel claims
between 1.2 and 1.9 tonnes of CO2 per tonne of steel, depending on the process.

5. The International Iron & Steel Institute (IISI), based in London is probably one of the most authoritative if not the most authoritative global reference for CO2 in crude steel.

Jarvis concludes, as his article title indicates that:
CO2 pollution from nuclear construction is irrelevant

He recognises and pin-points the many of the implications for energy sources and the urgency required if CO2 reduction is to be properly addressed.

"This ignores the pollution from getting the fuel and running the plant. Also remember the CO2 is largely produced up front, which is bad news for quick CO2 reduction, but even building 10 GW of capacity to replace the UK's ageing plants will only produce 3 million tonnes of CO2 during construction - less than 1% of UK CO2 pollution in one year."

Thanks Tim for an enlightening piece of work.

Sunday, 16 March 2008

How to Wedge-a-War on CO2 in the Steel Industry

Firstly-before getting involved:
It is best to arm ones-self with some sound statistics of main CO2 producers. For steel, CO2 goes hand-in-hand with steel production. These figures together with the CO2 correction factor are extensively given and well presented by country, region, "continents or uniform blockes", by company and company rank Top to bottom, tables and graphs notably by the International Iron & Steel Institute (IISI), based in London.
Secondly: support strongly, the most advanced practices, often these are most rapidly innovated, if not invented in the advance countries of the European Union. Flatering improvements in energy efficiency and CO2 reduction have been reported compared to other industrial sectors. Globally such results are likely to be countered by huge production increases and relatively poor emissions control in developing countries cf. below. However the above graph does show that important progress can be made in the "raw materials" phase of car making, the latter being the main outlet for steel.
NB. The energy intensity for all common ironmaking and steelmaking opperations is given clearly and in detail in the the paper Energy Use and Carbon Dioxide Emissions in the Steel Sector (April 2001) [Pdf] in Key Developing Countries by Lynn Price, Dian Phylipsen, Ernst Worrell, of the Energy Analysis Dept.,Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory University of California. Surprisingly for countries with enormous emission problems (China and India) this paper shows a relatively low C02 emissions level due to steelmaking compared to overall CO2 emissions. Nevertheless both countries have coal based energy economies and therefore carbon intensive. Carbon intensity trends are closely related to energy intensity trends but are also dependent upon the fuel mix used by the iron and steel industry in each country. Figure 20, in Energy Use and Carbon Dioxide Emissions in the Steel Sector (April 2001) [Pdf] shows that South Africa, India and China have the highest carbon intensities from iron and steel production, while Brazil and Mexico have relatively low carbon intensities.















System/Synergy 4 Approaches - Announced

This post will be based upon an up-to-date extract from a current specially CO2 - CCS focused curriculum vitae which reads as follows:


"Expert in the many aspects of manufacturing special metals & alloys from R&D to Market.

Special Interests: Innovation(s) - Eco-Engineering – Smart Materials
. Metallurgy, Special Alloys, Materials & Manufacturing Processes.
. Advanced Processes-Products-Markets.
. Science-Technology-Engineering (EBE -Environmentally Benign Eng. Approaches).

Durable Development -Intl. Support -Technical & Cultural–Bilingual, fluent french.

NB. Currently studying-reviewing Opportunities for new concept(s) for CO2 absorption with simultaneous production of Hydrogen, industrially oriented; Steelmaking, mining and metallurgical extraction =>energy production, distribution & control of industrial gas emissions:

-Systems /Synergy 4 Approaches
1. Mining (Coal)– Motivation Coal reserves France(58)-Scotland, Ayrshire.
2. Coal Powered Electricity & Heat generation – unavoidable for certain countries.
3. Metallurgy/Materials/Advanced Processes -my profession
4. FOCUS: CCS-Carbon, Capture & Stockage
-UN-G8 recommendation: Socolow "Wedge-a-War" theme.



Other on going work: structuring approaches to interdisciplinary applied science challenges. Examples are given cf. PROFESSIONAL EXPERIENCE...(CV on request) .

I wish to focus for the moment on what I call the Systems/Synergy 4 Approaches outlined above, a Triumvirate with an Aim, a Focus. The focus chosen being CO2, no one who wishes to understand the issues involved in CCS can refuse to read the conference papers made available freely by the organisers Bureau Regional de Geologie et des Mines (BRGM) and The Insitute for Petroleum (IFP). From memory, all papers are in english. This post goes further & is especially concerned with the metallurgical and chemical aspects of CCS-Carbon, Capture & Stockage, listed above.
(If I left other aspects or unfinished phrases it is on purpose, to leave the wider system of materials science, technology and engineering open to questions, requests suggestions: no-holds-bard.)
In my first blog "Conversations" I made several entries under the label C02 absorption. These and all labelled subjects may be found via the Site Search, Top Left, not the more visible WWW Google Customised Search Tool. The reader is free to browse both of course. More to point of the current post, are my posts entitled: The Metallurgy of CO2 Absorption with Simultaneous Production of Hydrogen
There I set out to demystify the simple combination of common metals with humid CO2 (ie CO2 absorption by a metal) resulting in a metal carbonate with simultaneous production of Hydrogen.
The commonest natural process, known to all, is iron rust, Iron (Fe) in the presence of wet(H20) carbon dioxide (CO2) gives Iron Carbonate (FeCO3) giving off Hydrogen gas (H2).
Please read the full post: The Metallurgy of CO2 Absorption with Simultaneous Production of Hydrogen. To the best of my knowledge, this is a good review of the state of the art at the time (mid 2007) Naturally from a metallurgical science point of view or a metalurgical process and chemical engineering stance many finer point must addressed to obtain an economically viable process and value added products (mainly the much talked of H2 fuel vector & FeCO3) all contributions - colaborations welcomed to "Wedge-a-War"
To get involved it is best to arm ones-self with some sound statistics of main CO2 producers. For steel, CO2 goes hand-in-hand with steel production. These figures together with the CO2 correction factor are extensively given and well presented by country, region, "continents or uniform blockes", by company and company rank Top to bottom, tables and graphs notably by the International Iron & Steel Institute (IISI), based in London.

High Purity Cr sources for Superalloys

Energy for th Future:Phil.Trans.A-Vol. 365, N° 1853 / April 15, 2007, curtesy The Royal Soc. London

Engineered foams and porous materials: Phil Trans A. Vol 364, N° 1838 / 06 curtesy_The R Soc. Lond