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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
(56) 2004, nr.7, p.5
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.
Key words: dental alloys
Lucia Staicu, George Vermeşan, Cătălin
Popa: Pages out of the history of restorative dental
materials
Metalurgia
(56) 2004, nr.7, p.10
The most
important historical moments, from birth to the development of restorative
dental materials, are presented in the first part of this work. In the second
part, the names of some modern manufactured articles in the dental materials field are
schematically given and some next tendencies
are finally put down.
D.C : 669.14.018.252.3
Marian
Ionescu: Study regarding the quality of maraging
type steel depending
on technological processes
Metalurgia
(56) 2004, nr.7, p.18
Experiments developped with maraging type steel
(Ni-18%; Mo-5%; Co-9%; Ti-0,7%) took into consideration the improvement of
physical-mecanical proprieties under different process conditions of steelmaking and casting.
Experimental results put into evidence the achievement
of superior characteristics of strength and toughess, when induction furnace
under protection athmosphere is used for melting and electric remelting under
syntethic slags is used for refining.
D.C.: 669.14.018.25
Alin
Stăncioiu: Research Concerning at the Heat Treatments in the Qualities Tools
from the Cutting Steels (part II)
Metalurgia
(56) 2004, nr.7, p.22
The present
paper is a continuation (1) for the quantification of the stresses and
strains of the cutting tools.
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A method which is continuously
developing and also
economic as time and material costs is the use of virtual methods and their
analysis through the finished element method which is in close connection
with the computers' software and the hardware development
The Von Mi
sis stresses show the stress distribution which varies from the cutting
edges, where the stress values are maximal up to the abutment part at the contact
with the pressure plate, where the stress values are minimal. Due to the
greater lengths of the tools compared to their diameters, the buckling
phenomenon occurs, represented in diagrams where the strains on the Ox axis
are observed.
These
analyses have appreciated the role of
heat treatments in the durability of the cutting tools.
D.C.:669-14; 621.785.1
Vasile
Caţarschi: Experimental Researches Conducted in Industrial
Conditions to Check some C++ Language Software at Heating Steel Ingots with Cold
Intitial Condition
Metalurgia
(56) 2004, nr.7, p.30
In present work proposes itself to show
the advantages of modern heating technologies for plastic deformations in
comparison with the existent technologies for steel cold ingots. This new
technologies uses special PC programmes for the thermal systems measurement,
in C++ language. In programmes Heiligenstaedt methodology is used
as well as Bessel-Fourier functions and the decoupling principle, this
principle permitting, from the point of view of the heating transfer
calculation, the heated metal to be separated from the furnace. The criterion
adaptation can safely replace difficult industrial investigations, thus
proving its utility for practical situations.
D.C.: 622.785
Toderiţa
Nemeş, Valentin Petrescu: The elaboration
of the optimized charge recipe for the agglomering
process in the I.S.P. technology based on the mathematical
model
Metalurgia
(56) 2004, nr.7, p.43
Based on a
mathematical model, which establish three interdependent quality conditions
(Zn/Pb = 1.6 2.1; Pb/Cu = 18 23; Sagl = 0.98 1.8%) needed
simultaneously for the Imperial Smelting Processes technology, it was studied
the possibility of elaboration of the optimum recipe for the agglomeration
charge.
The
experimental researches consisted in a chemical analysis of three types of
charges (A, B, C) formed of selective concentrates of Zn and Pb, oxidic
materials, optimized return agglomerates and fluxes available in the
materials stock.
The results
of the experimental researches show that B charge represents the optimum
recipe for the agglomerate process.
The
B Charge contains 38% Zn, 19% Pb, 0.93% Cu and 6.7% S and respect the quality
conditions recommended by the I.S.P. technology and are certified by the
suggested mathematical model.
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