Relationship between crystallographic textures in fully annealed silicon bearing non-oriented electrochemical steels and magnetic parameters, in particular, energy loss in rotating machines

European Union

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Industrial research and development

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• Sciences et techniques

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• Publié par: EUROPEAN-UNION
• Nombre de lectures: 7
• Langue: English
• Poids de l'ouvrage: 4 Mo

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Commission of the European Communities
technical steel research
Properties and service performance
RELATIONSHIP BETWEEN CRYSTALLOGRAPHIC
TEXTURES IN FULLY ANNEALED SILICON
BEARING NON-ORIENTED ELECTROTECHNICAL
STEELS AND MAGNETIC PARAMETERS,
IN PARTICULAR, ENERGY LOSS IN ROTATING
MACHINES
Report
EUR 10135 EN
Blow-up from microfiche original Commission of the European Communities
technical steel research
Properties and service performance
RELATIONSHIP BETWEEN CRYSTALLOGRAPHIC
TEXTURES IN FULLY ANNEALED SILICON
BEARING NON-ORIENTED ELECTROTECHNICAL
STEELS AND MAGNETIC PARAMETERS,
IN PARTICULAR, ENERGY LOSS IN ROTATING
MACHINES
J.H.R. PAGE
BRITISH STEEL CORPORATION
9, Albert Embankment
GB-LONDON SE1 7SN
Contract No 7210-MA/806
(1.4.1982 - 30.9.1984)
FINAL REPORT
Directorate-General
Science, Research and Development
1986 EUR 10135 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Information Market and Innovation
L 2920 LUXEMBOURG
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting
on behalf of then is responsible for the use which might be made of
the following information
>ECSC-EEC-Euratom, Brussels· Luxembourg Relationship Between Crystallographic Textures in Fully
Annealed Silicon Bearing Non-Oriented Electrotechnical
Steels and Magnetic Parameters, in Particular,
Energy Loss in Rotating Machines
FINAL REPORT
Agreement 7210.MA/8O6
J.H.R. Page
Electrical Steel Research Dept.
A.P.G. Newport
EUR 10135 EN FR 123 6 842 7210.MA/806
RELATIONSHIP BETWEEN CRYSTALLOGRAPHIC TEXTURES IN FULLY ANNEALED SILICON BEARING
NON-ORIENTED ELECTROTECHNICAL STEELS AND MAGNETIC PARAMETERS, IN PARTICULAR,
ENERGY LOSS IN ROTATING MACHINES
British Steel Corporation
ECSC Agreement No. 7210.MA/806
Final Summary Report
The objective of this research project was to obtain an understanding of the
relationship between crystallographic texture in fully annealed silicon bearing
non-oriented electrotechnical steels and their magnetic behaviour. This p is well understood in 3% Si grain oriented electrotechnical steels
where only onec texture predominates, but the effect of differing
texture components, in varying amounts is less well understood.
The work was divided into three main areas; the production of a series of alloys
in which by alteration of rolling and annealing cycles, changes in
crystallographic textures were produced; the evaluation of these textures and
their associated magnetic properties; and the effects these changes had upon the
performance, as measured by variations in Magnetic Flux and Power Loss
distribution, together with related variations in building factor of a rotating
machine.
Studies were undertaken on 1.3% Si and 3% Si materials of both commercial and
experimental compositions; in the latter the remaining elements lay broadly, but
not exclusively, within the range currently employed in fully annealed silicon
bearing non-oriented electrotechnical steels. Samples of each material produced
were finish processed along three basic routes. They were either cold reduced
directly to a final gauge of 0.5mm and then annealed; or cold reduced to a
thickness approximately 10% greater than the final gauge of 0.5mm, annealed to
recrystallise and decarburise, reduced to final gauge, then finallyd to
promote grain growth; or coldd to a thickness some 50% greater than final
gauge, annealed to recrystallise and decarburise, cold reduced to a final gauge of
0.5mm, and once again annealed to promote.grain growth. Upon completion of
processing, samples were prepared for magnetic measurements, crystallographic
texture studies, and the production of simulated core materials.
The results of this investigation indicated that it was possible, in the majority
of cases, to explain the overall shape of the magnetic anisotropy curves produced
in terms of the crystallographic texture components present. Further it was again
possible in the majority of cases to explain the variations in such anisotropy
curves in a given material, subjected to changes in processing, by variations in
the components present.
It was also observed that methods of measurement of magnetic anisotropy that rely
solely on a measure of the Power Loss in the longitudonal and transverse
directions are not reliable since they do not take into account the affects of
maxima in Power Loss values at angles other than 0° or 90° to the rolling .
Of the variations in chemistry examined whilst all changes affected the overall
Power Loss levels achieved, only Aluminium above a critical level and under
specific processing conditions appeared to have any affect upon the form of the
anisotropy curve. Heat treatment of the hot band prior to finish processing
produced variations in final anisotropy that could be explained by the observed
texture differences.
This investigation has also shown the extent to which harmonic flux and rotational
flux affects the Power Loss with various degrees of anisotropy present and that
the Total Power Loss of a rotating machine is critically dependent on these
factors. FR 123 6 842 7210.MA/806
The most desirable characteristics of a material for a rotating machine are a low
absolute Power Loss combined with isotropic magnetic characteristics.
Some correlation of computed losses with material properties was obtained, but
further work is needed to fully understand the effects of texture on the
performance of rotating machines. However, the present investigation has
indicated the areas requiring further study and has laid a foundation upon which
to pursue such work.
11 FR 123 6 842 7210.MA/806
CONTENTS PAGE NO.
1. INTRODUCTION
1
2. MATERIALS
2
3. EXPERIMENTAL
3.1. Ingot Production
3.2. Hot Rolling
3.3. Finishing Processing
3.4. Magnetic Measurements
3.5. X-Ray Crystallography
4. RESULTS
5. DISCUSSION
5.1. Commercially Produced 3% Si Steel - Alloy 3A
7
5.2. Laboratory Processed 3% Si Sample 18AOG
9
5.3. Effect of Variations in Finish Processing
10
5.4.t ofs in Chemistry 12
5.5. Effect of Heat Treatment of Hot Band Prior to 19
Finish Processing
5.6. Effect of Tin 22
6. WORK UNDERTAKEN AT THE WOLFSON CENTRE FOR MAGNETICS TECHNOLOGY 23
23 6.1. Introduction
23 6.2. Materials
24 6.3. Computation of Loss and Flux Distribution
25 6.4. Measurement of Losses Under Distorted Flux Conditions
27 6.5. Assessment of Rotational Power Loss Characteristics
28
6.6. Relationship Between Computed Losses and Experimental Data
28
7. CONCLUSIONS
29
8. REFERENCES
30
TABLES
88
FIGURES
111