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EURO 120 |
Metalurgia INTERNATIONAL English version, published by romanian metallurgical foundation Honorary president of scientific
publishing house f.m.r. Dr. ec. Lepădatu v. gheorghe
vol.
X (2005) no.3 romanian metallurgical
foundation Scientific publishing
house |
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romanian metallurgical
foundation Scientific
publishing house scientific board staff Professor AVRAM NICOLAE Ph. D. professor Costin Scorţea Ph. D Managing Director: Professor Costin Scorţea Ph.
D. Editor-in-chief: Professor Nicolae Avram Ph. D. Professor Maria Nicolae Ph. D editorial board: Prof.
dr. ing. bejan Mircea Prof.
dr. ing. bunea Daniel Prof.
dr. ing. cănănău
nicolae Prof.
dr. ing. GEORGETA COŞMELEAŢĂ Prof.
dr. ing. CIUCĂ ION Prof.
dr. ing. gaba aurel Prof.
dr. ing. GĂLUŞCĂ DAN GELU Prof.
dr. ing. hepuţ teodor Prof.
dr. ing. IONIŢĂ GHEORGHE Prof.
dr. ing. mănescu tiberiu Conf. univ. dr. ing. TODERIŢA NEMEŞ Prof.
dr. ing. samoilă Corneliu Prof.
dr. ing. SCORŢEA COSTIN Prof.
dr. ing. SIMITI IOAN VIDA Prof. dr. ing. SOFONEA GALAFTION Prof.
dr. ing. Şaban Rami Manager Scientific Publishing House F.M.R.: eng. Florentina Brânduşa Scorţea |
Contents Issn 1582 – 2214 Cojocaru V. Dănuţ: Compression behaviour of hitperm alloys at 600oC ………………………………………………………….……....
3 Ana Josan,
MAKSAY Ştefan, Doina PETRE, Ana SOCALICI, Erika ARDELEAN: Studies
and researches for settling the
optimal area of chemical composition for cast Adamit-type
hypereutectoid steel rolls ………………………………………….……..…..… 14 Elena Drugescu, Alexandru
Petrică: The quenching of low carbon steel thin
strips …….…………. …………………………… 22 KISS Imre, MAKSAY Stefan: Optimisation model and
mathematical modelling in MATLAB area in the case of ductile cast irons ……………………………………………………….……......….
28
Erika ARDELEAN, Ardelean
Marius, Ana Socalici, Ana Josan: The effects
of operational parameters on secondary solidification of continuous cast semifinished parts
………………… 35 Chichernea Ilca Ioan:: Optimisation
of the thermal treatment technologies for the cast hypereutectoid steel rolls
………………………..………… 48 ? Press release ……………..………….....………….……............
I ?The fifth International Congress in materials science and
engineering …………………………...……………………... II-III ? New
books ………………………………………………….….. IV ?New books, published by romanian metallurgical foundatio n ..……………………………………….…..… VII-VIII |
abstract
metalurgia International 3/2005
|
D.C.: 669.2/.8 Cojocaru V. Dănuţ: Compression behaviour of hitperm
alloys at 600oC Metalurgia International (vol. X), no.3, 2005, p. 3 Over
the last decade, nanocrystalline materials were
investigated for applications in magnetic devices that require soft magnetic
materials (transformers, inductive devices, etc). The benefits of nanocrystalline alloys stem from their chemical and
structural variations over nanometer scale which are
important for developing optimal magnetic properties. HITPERM-type alloys : Fe–Co–Zr–B–Cu : provide
nanocrystalline phases with bcc a’-FeCo (B2) structure. High induction bulk materials, including
HITPERM-type alloys, were investigated,
however less attention
has been paid
to the stability
of nanostructured materials under extreme
conditions of pressure and temperature. The main aim of the present work is
to study the compressibility of the bcc a’-FeCo (B2) structure under pressures up to 3
GPa for a temperature of 600°C. HITPERM-type alloy powders were prepared by high-energy
ball-milling. The evolution of structure parameters was evaluated using
synchrotron radiation X-ray diffraction. D.C.: 669.018.25 Metalurgia International (vol. X), no.3, 2005, p.7 The
size of this zone changes due to the mass transfer that is obvious in the
process of extrusion and heat treatments. These stages provide for the
kinetics and
thermodynamics of the
interface processes, therefore
they have, an important role in determining the final properties of the
composite. D.C.: 621.771 Keywords: Adamit - type steel,
chemical composition, hardness Ana Josan,
MAKSAY Ştefan, Doina PETRE, Ana
SOCALICI, Erika ARDELEAN: Studies
and researches for settling the
optimal area of chemical composition for cast Adamit-type
hypereutectoid steel rolls Metalurgia International (vol. X), no.3, 2005, p.14 The paper introduces the results of
statistical mathematical processing, by means of the MATLAB calculation
program of the data related to 29 rolling cylinders cast at S.C. Siderurgica S.A. Hunedoara, in
view of determining the optimal chemical composition domain. For the
cylinders under consideration we gave the chemical compositions and the hardnesses we registered. Once the domain of chemical
composition has been restricted, important material economy can be obtained,
which has a direct impact on the manufacturing price of
cylinders cast of Adamit-type steel, thereby
reducing the expenses of the company. D.C.: 621.771.23 Elena
Drugescu, Alexandru Petrică: The quenching of low carbon
steel thin strips Metalurgia International (vol. X), no.3, 2005, p. 22 The
quenching of low carbon thin strips For plain carbon steels with very low
carbon content the usual method for improving the strength is the cold work
hardening and the quenching, which are considered an ideal process for this
category of alloys. The investigation was oriented to the performance by
quenching of packaging and strapping steels. For quenching, three different bath were employed: water, salt-water (5%NaCl) and
salt-water (10%NaCl). Experimental
results show that quenching is superior to cold work hardening, as far as the
low carbon steels are concerned. |
D.C.: 669.131.622 Keywords: :mathematical
molding, Matlab area, mathematical correlations,
graphical addenda semihard cast nodular iron
rolls, alloying elements, hardness KISS
Imre, MAKSAY Stefan: Optimisation model and mathematical modelling
in MATLAB area in the case of ductile cast irons Metalurgia International (vol. X), no.3, 2005, p. 28 The
paper presents the results of some researches regarding the chemical
composition of the ductile irons destined for casting semihard
rolls. It is presented, in graphical form, using the MATLAB area, the
influence of the main alloying elements upon the hardness measured on the
necks and on the core. This
paper suggest a mathematical interpretation of the influence of the main
alloy elements on mechanical characteristics (the hardness on the necks
and the core of
the rolls) of this
ductile irons, resulting
the average values
and average square errors of the variables HS, and the main
alloying elements (Cr, Ni, Mo), the
equations of the hyper surface in the four dimensional space. For the
statistical and mathematical analysis, there were used 23 industrial cases.
The resulted surfaces, belonging to the three-dimensional space, can be
represented and, therefore, interpreted by plant engineers. Knowing
these level curves allows the correlation of the values of the two
independent variables so that the hardness can be obtained in between the
requested limits. D.C.: 621.74.047 Erika
ARDELEAN, Ardelean Marius, Ana
Socalici, Ana Josan: The
effects of operational parameters on secondary solidification of continuous
cast semifinished parts Metalurgia International (vol.X), no.3, 2005, p.35 When
cooling the semi-finished parts in the mould, the secondary cooling takes
place. During this, the solidification has to be performed on entire cross
section of the strand. In order to achieve this, beside a proper primary
cooling, the factors that influence the secondary cooling have to be also
correlated: the water flow on three areas on the installation, the water
pressure in the secondary circuit, etc. All
these have in view a proper solidification length; an intense cooling can
generate cracks due to the thermal stresses, while a too slow cooling can
generate a partial solidification of the strand up to the cutting machine
area. The paper shows also the differences that appear
during the continuously casting of three different sections: 240x270 mm
bloom, Ø 150 mm and Ø 180 mm billet. D.C.:621.74 Keywords: modeling, the static break, running, feeding, cast steel Chichernea Metalurgia International (vol.X),
no.3, 2005, p. 42 In
the laboratories of the Materials Science and Engineering Faculty of the Transilvania University of Brasov
a number of theoretical and experimental studies have been conducted on the
3D – modelling of part casting with gating and
shrink heads, as well as on the modelling of
breaking generating strains. D.C.:
669.15-194.52 Ilca
Ioan::
Optimisation of the thermal treatment technologies
for the cast hypereutectoid steel rolls Metalurgia International (vol.X),
no.3, 2005, p. 48 There
are established three alternatives of thermal treatment improvement of adamite rolls in order to obtain several rolling tools at
higher quality parameters. The secondary thermal treatment of normalisation followed by tempering ensures the necessary
hardness, the structure stabilisation and the
stress reduction at minimum as well as physical-mechanical properties of the rolls that are
necessary in the rolling process. |