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D.C.: 574
Avram Nicolae,
Cristian Predescu, Diana Parpală, Mihai Licurici: Analysis
of the nitrogen oxides (NOX) generation during the polluting
metallurgical processes
Metalurgia
International (vol.IX), no.3, 2004, p. 3
The analysis
of the scientific concerns in achieving a clean metallurgical medium
emphasizes two main aspects:
v
the efforts
focusing especially on the stage after the polluting emissions generation,
taking major measures to recover the secondary materials;
v
the
insufficient knowledge of the mechanism and
kinetics of the
pollutants generating processes (especially in the case of the
metallurgical technologies); this fact influences negatively the possibility
to forecast the amounts of polluting substances generated during an
industrial process.
Starting from the above said, in this paper
are approached two problems:
v
the
analysis of the qualitative aspects regarding the nature of the nitrogen
oxides generation;
v
the achievement
of some algorithms used to forecast the nitrogen oxides volume generated
during the metallurgical process.
D.C.:
574
Maria Nicolae, Avram Nicolae,
Cristian Predescu: Possibilities to estimate
the ecological efficiency by improving the parameters
of sustainable development
Metalurgia
International (vol.IX), no.3, 2004, p. 7
The dialectical approach of the activities
carried on in order to obtain an ecological industrial medium (the main
component of the model of sustainable development) emphasizes that the major
concern must be not the stage of post-pollution (when, e.g., the secondary
materials recycling is recommended), but the stage of pollutant processes
prevention and reduction. The application of this idea supposes:
v
the
intensification of the scientific efforts to lie the basis of the theory and
practice concerning the pollutant emissions generation (the secondary
materials recycling included);
v
the
finalization of the methodologies for estimating the ecological efficiency, EEecol. (eco-efficiency),
when technical and technological measures for industrial pollution prevention
are taken.
In this paper a special attention is paid
to the second aspect.
D.C.: 620.179.16
Marian Bordei,
Aurel Ciurea: The rolls
discontinuities detection of the continuous casting machines
by ultrasonic control
Metalurgia
International (vol.IX), no.3, 2004, p. 11
The
ultrasonic examination has for an object the pointing out of the internal
discontinuities obtained after the plastic deformation process, process that
can end with the
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appearance of some
defects such as: shrinkage, cracks, flakes, metallic and non-metallic
inclusions.
The ultrasonic examination can be
applied to a large amount of materials, the limitations being determined by
the size of the structural granulation in the case of the metals. Having a
special penetrability, the ultrasounds permit the examination of large
thickness sections, the distances crossed inside the steel pieces reaching
about 5 m.
The result
of the control is immediately obtained and the co-ordinates and the size of
the defect can be accurately determined.
D.C.:
669.131.622
Aurel Ciurea,
Marian Bordei: Considerations upon
breaking strength of nodular cast iron under plastic
deformation
Metalurgia
International (vol.IX), no.3, 2004, p.17
The work
aims to demonstrate the existence of a mathematics connection between
breaking strength and degree of plastic deformation in case of nodular cast
iron.
Research made along time starting
1932-1934 until now, showed that cast iron can be both hot and cold
plastically deformed. Deformation degrees reached on various types of cast
iron show that plastic deformation is influenced, mainly, by the following
factors: chemical composition; cast iron
shape; basic metallic
mass structure; plastic deformation temperature; tension condition
generated by plastic deformation; deformation speed. As a result of plastic
deformation, the cast iron pieces change their shape and size as well as the
breaking strength value. The latte increase together with the deformation
degree.
Present work analyses the breaking
strength depending on the deformation degree for a nodular cast iron (450.5).
Key words: concurrent engineering,
numerical simulation, dielees drawing
Mariana Pop: A
Concurrent Engineering System with
Industrial Application
Metalurgia
International (vol.IX), no.3, 2004, p. 22
If a final product has to be produced without
mistakes, the development process must be supported by means of modern
techniques. The most important methodology in designing a new product is the
concurrent engineering and its specific tools to lower the
development and manufacturing times. In this paper a special emphasis is
given to use mathematical simulation of dieless
drawing process. Dieless drawing of
wires and bars is a non conventional process of plastic deformation which
present some advantages compared to classical one. Dieless
drawing is an incremental process of plastic deformation by the help of local
inductive heating. In this process temperature and plastic deformation
affect each other, that is why the deformation behavior is very complicated.
The aim of this paper is to present some principles of mathematical modeling
for the dieless drawing process regarding the
process control for producing variable cross-sections(
cone-contour and sinus-contour).
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