Measurement and Control in Liquid Metal Processing: Proceedings 4th Workshop held in conjunction with the 53rd International Foundry Congress, Prague, Czechoslovakia, September 10, 1986

199 Pages·1987·5.923 MB·English

by  Ir. J. Plessers (auth.), René J. Moreau (eds.)

MEASUREMENT AND CONTROL IN LIQUID METAL
PROCESSING
Measurement and Control in
Liquid Metal Processing
Proceedings 4th Workshop held in conjunction with the 53rd
International Foundry Congress, Prague, Czechoslovakia,
September 10, 1986
edited by
RENE 1. MOREAU
Natronal Polytechnic Institute, Grenoble, France
1987
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ISBN -13: 978-94-010-8110-8 e-ISBN-I3: 978-94-009-3599-0
DOl: 10.1007/978-94-009-3599-0
Copyright
© 1987 by Martinus Nijhoff Publishers, Dordrecht.
Softcover reprint of the hardcover 1st edition 1987
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v
PREFACE
R. J. MOREAU, Professor
MADYLAM, Inst. Nat. Poly technique de Grenoble, France
The material on which the foundryman 1S focus1ng his attent10n 1S a
molten metal, ferrous or not, coming from the melt1ng equipment, Wh1Ch is to
be del1vered into a mould where it w1ll solidify. The foundryman 1S the last
person 1n th1S process who still has the poss1b1l1 ty of acting to control
the quality of the casting. Indeed, most of the respons1bil1ty 1n th1S
quality bus1ness is vested 1n him. Bes1des, as anyone involved 1n metals
processing, he 1S engaged 1n the ongoing effort to achieve the highest
eff1c1ency and the best working condit10ns.
To deal w1th th1S metal he needs to know f1rst its physical properties
(temperature, composit1on, 1mpur1ties ... ) and the way they influence 1tS
behav10ur (llqU1dus, solidus, structure •.. ). He also needs to know how this
complex flu1d flows (head losses in gating parts, flow rates, levels in
moulds ... ) and 1S modif1ed by its enV1ronment (heat fluxes, temperature
var1at10ns, solidification ... ). Responding to th1S need requires an
important and regularly updated knowledge as well as preC1se measurements
and advanced control processes. One may therefore appreciate why the topic
"MEASUREMENT AND CONTROL IN LIQUID METAL PROCESSING" was chosen by the CIATF
for the 1986 workshop. The title clearly ind1cates that the interest 1S
llmited to the metal in the llqu1d state, flow1ng through the gating parts
and f1lling the mould, with a particular emphasis on the measurement
techniques and the control processes. The a1m was ObV1ously to brlng
together 1nformatlon and results on the data, tools, techn1ques and
procedures available and applicable to foundries.
The present period of t1me, at the end of the 1980's, during Wh1Ch were
discussed these techn1ques and their advantages or disadvantages pointed
out, seems to me to offer particularly r1ch possibil1ties. It is ma1nly
characterlzed by the following trends :
* Computers, and particularly mlcrocomputers, now are cheap enough and
reliable enough to enjoy widespread use in the metallurgical 1ndustry
notably 1n foundries. More than the1r low price their rel1ab1l1 ty 1S
certainly an essent1al factor account1ng for the1r extensive use. It permits
their use in very severe enV1ronments such as 1n melt1ngshops and
foundries, in the presence of host1le dust and 1n d1ff1cult thermal
condit1ons.
* Manual operations, 1nherently slow, are replaced on a large scale by
automatic operat1ons Wh1Ch are much more rap1d, less random, and cheaper.
Eng1neers and SC1ent1sts part1c1pat1ng 1n th1S meet1ng were certa1nly well
prepared to analyse the techn1cal aspects of that iportant development. But
social and econom1C aspects, Wh1Ch are certa1nly among the pr1or1tles, have
generally been kept outside the agenda.
VI
When Mr. GRANDPIERRE, President of the French ATF, and Mr. FERRERINHA,
President of the CIATF, invited me to chair this workshop, I was so
convinced that the subject was prom~sing that I had no choice but to accept.
,low, a few weeks after the meeting, as I am fin~shing the preparation of
this book, I realize that their invitat~on was indeed a great honour. I am
convinced that these proceedings represent a very valuable body of knowledge
and technique. I am confident that the ~nformatlon, data and suggest~ons
repor~ed by the 16 authors and by the many speakers who partiClpated the
discussions will play a significant role in forthcoming improvements and
developments of the technology in casting processes.
This workshop was d~vlded into three sessions, the first two being
themselves subdivided into two subsessions. The chairman of each session or
subsession was the first speaker he introduced the whole session or
subsession before presenting his own paper. The sess~on-chairmen were also
invited to be members of the panel during the global closing discussion.
Titles of the sessions and subsessions were :
1. Measurement procedures and equipment
1.1 Measurement of phys~cal values
Chairman: J. Plessers
1.2 Quality control of melts
Chairman: J. Charbonnier
2. Fluid flow phenomena
2.1 Fusion equipment
Chairman : L. Hallot
2.2 Mould filling
Chairman R. D. Pehlke
3. Automation
Chairman C. Sourisse
Each of the first two sessions comprised 6 papers followed by a 30
minute discusslon the third session comprised 4 papers and a 15 minute
discussion. Finally, the meeting ended after a 90 m~nute panel discussion.
This panel discussion ltself was divided in two parts. During the first 45
minutes, each session-chairman was invited to raise and to comment on points
of special interest ; dur~ng the second part, participants were also invited
to raise questions and panelists, as well as other partic~pants, had the
opportun~ty to answer or to comment.
A total of 2 hours and 15 minutes was therefore devoted to the
discussions. A summary of their contents is lncluded in these proceed~ngs.
VII
Acknowledgements
I wish to express my gratltude to Mr. Maurice GRANDPIERRE and Mr. Robert
PORTALLIER, respectively Presldent and Vice-President of the French ATF, who
lnvited me to chair thlS workshop and who worked a lot in its preparatlon.
My sincere thanks are also due to Mr. Regis FOUQUES DUPARC, General Delegate
of the French ATF, for his precious help ln all the technlcal matters.
I am very grateful to all the authors and particularly to those who
particlpated in the preparatory meetlngs ln Paris and Grenoble.
The success of thlS workshop was also due to the members of the Local
Organlzing Committee, and particularly Prof. Karel RUSIN, Dr. Igor MACASEK
and Dr. Stanislav HANZL, to whom I am very indebted.
Finally, I wlsh to thank Pechlney Aluval and the Ecole Natlonale
Superleure d'Hydraulique et de Mecanlque de Grenoble, and their secretarles
who shared the tYPlng of the camera ready forms.
IX
CONTENTS
Preface ........•...•..........................•......•.. R.J. MOREAU V
Acknowledgements ......•.........•...•..........................•... V I I
1. MEASUREMENT PROCEDURES AND EQUIPMENTS
1.1. MEASUREMENT OF PHYSICAL VALUES
Temperature measurement .....••.••.•••.••.............. J. PLESSERS 3
Determination of the Quantity of Liquid Metal
Deli vered to the Mould ....•.............•..•...• W. KLINGENSTEIN 11
1.2. QUALITY CONTROL ON MELTS
Control of Structure in Aluminum Alloys
by Thermal Analysis .............................. J. CHARBONNIER '21
Thermal Analysis in Ferrous Foundries .•.........•......... R. DOEPP 39
Microstructural Control by Electrical
Reslstivity of Strontium Modlfied Alloys B. M. CLOSSET 53
Rapid Determination of Oxygen and
Oxides in Fe-C Alloy .....•......•...•......•........ R. PRUMBAUM 75
2. FLUID FLOW PHENOMENA
2.1. FUSION EQUIPMENT
New ways of running crucible induction furnaces ........ L. HALLOT 83
Relationshlp between Impedance and Diameter .•.........•. R. ERNST 93
2.2. MOULD FILLING
Thermal Aspects of Mould Filling R. D. PEHLKE 99
Reflning of Melts by Flltration. A water
Model Study •...................•...................•. M. DEVAUX 107
3D Visuallsation of Mould
Filling ..............•..•. C. GALAUP, U. DIETERLE, andH. LUEHR 117
Optimal Gatlng for Thln Wall Parts .........•............ R. HAMAR 129
x
3. AUTOMATION
Trends ln Molten Metal Process
Automation Techniques ............................•. C. SOURISSE 145
Automation of an Induction
Mel tingshop at Brebach •.•.•..............•......••..• M. BREINIG 161
Automatic Metal Stream
Inoculation .................... 1. C. H. HUGHES and K.C. TAYLOR 171
Illustration of Automation in Metal
Processing at Carmagnola Plant ..•.............•...... R. MEDANA 191
4. DISCUSSIONS
A Summary of the D1Scussions ..•........ R. J. MOREAU and F. DURAND 199
MEASUREMENT PROCEDURES AND EQUIPMENTS
3
TEMPERATURE MEASUREMENTS
Ir.J. PLESSERS,
Electro-Nite, Houthallen, Belgium
1. INTRODUCTION
Temperature measurements are of enormous importance in
foundries for the control of energy, refractory wear and
especially quality of the castings.
2. MEASURING PRINCIPLES
The two main measuring techniques used in foundries are
thermocouples and radiation thermometers. Both techniques have
made important progress in recent years.
2.1 Thermocouples
Thermocouple wire accuracy is now improved, so that
temperature measurements can easily attain accuracies of +/
1°C. From the different types the Pt-PtRh thermocouples are
used mainly in foundries for the high temperatures
(lOOO-1700°C) and Ni-NiCr thermocouples for lower temperatures
(up to l3000C).
To be mentioned here is the important progress that has
been made in the emf stability of Ni-NiCr thermocouples with
the addition of silicon in the alloy (Nickel-Chromium Silicon
thermocouples).
Sheaths for protection of thermocouple wires have been
developed so that in nearly all circumstances - also in highly
agressive media - temperature can be measured continuously. As
an example the use of boron-nitride as a protection sheath in
the continuous measurement of steel temperatures can be
mentioned.
But the biggest progress has been made in the electronic
instruments for measuring and displaying temperature. For
example a digital display hand-help (fig. 3) or on big
displays is very popular in foundries. Also the automatlc
interpretation of cooling curves for thermal analysis should
be mentioned here (flg. 4) It illustrates the use of
microprocessors for automatic interpretation of thermocouple
data.