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D.C.: 574
Paul Tudor, Avram Nicolae, Maria Nicolae, Cristian
Predescu, Diana Parpală: Sustainable development requires new exigences in the supplier-customer relationship
Metalurgia
(56) 2004, nr.10, p.5
Alignment of
activities in the field of resources procurement to the requirements of
sustainable development concept assumes a new orientation of
supplier-customer relationship. Some of directions supporting the new
orientation are characterized in the study: influence of liberalisation,
importance of interventionist practices and concepts, the role of environment
quality the requirement of function of attendant to development, the
apparition of new technologies for scrapquality
improvement.
D.C.:
669.295
Doina Răducanu, Lucia Angelescu, Ion Cincă,
Dănuţ Cojocaru: Plastic Deformation behaviour of Commercially Titanium
used for Dental Implants. Part I: Hot
plastic deformation
Metalurgia (56) 2004, nr.10, p.12
The
purpose of this paper is to show some experimental results about elastic
deformation behavior of a Commercially Titanium. The amount of elastic deformation
depends on the purity of the alloy, grain size and strain rate.
The
experiments are based on the micromechanics effects when a rigid indentor penetrates a flat surface of a material which
has the ability to deform elastic or plastic. The deformation was performed
by micromechanical testing, using an indentation device which can work with
spherical indentors.
Data
about the penetration depth can be used to express the quantum of elastic
deformation.
The
experimental research
are focused on elasticity, measured in different conditions.
This part of
the article threats the effects of hot plastic deformation.
D.C.:
669.5
Tamara Radu, Stela Constantinescu: Structure and proprieties
of zn coatings microalloyd
with Al
Metalurgia (56) 2004, nr.10, p.18
The presences of the aluminium
in the galvanizing bath have a positive influence on the structure and on the
properties of the obtained layer. Aluminium
decreased zinc reactivity for iron, limiting the appearance of the zinc-iron
compound, and lead to an easier coating on square metre at
product. There obtained shiny layers with an increase corrosion resistance
for galvanizing products
D.C.:
669.141
Carmen Medrea Bichtas, Gavril Negrea, Şerban
Domşa: Studies
regarding the microstructure of warm worked low carbon
steel
Metalurgia (56) 2004, nr.10, p.24
Plastic deformation at warm temperatures (warm working) offers a series
of advantages as compared to hot and cold working. This paper presents a
study on the influence of warm rolling with different
deformation ratios (10.4%, 20.0% and 36.4%) of a low
carbon steel (0.15% C) on its microstructure. The investigations were
performed by optical microscopy (including quantitative
analysis) and electronic microscopy. The results showed that warm rolling can
be considered as a viable technological route for certain industrial
applications.
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D.C.:
621.771
Stela Constantinescu:
Researches of the Modification Structurals and Properties of Plates made from Steel RV52
Metalurgia (56) 2004, nr.10, p.30
The steel plates RV52 are used to
manufacture liquefied and compressed gas reservoirs, recipients and pressure vessels
operating at low pressures and highly loaded structures.
The
normalized plate sample were studied to determine the effect of the tension
release heat treatment on the properties of these plates intended for
metallic welded constructions.
From the
relations expressing the link between the strength and
tenacity relations on one hand and the structural characteristics, on the
other hand it is obvious that the only factor which leads both to better
strength properties and lower transition temperature is the refining of the
ferrite grains.
D.C.:
669.24
Simona Boiciuc, Radu Boiciuc: Tests Performed of Nickel Layers Electro-Plated on
Mould Plates of Steel Continuous Casting
Metalurgia (56) 2004, nr.10, p.36
This paper
contains series of trials I conventional temperature conditions regarding the
behaviour of the nickel coating on a copper
support, in order to use them on the hardening of the mould plates surfaces
from the continuous casting of steel. It presents the tests for a hetrtzian contact between a ball-shaped head and the
samples made of copper and copper electrochemically coated with nickel in two
different layers. This paper presents the first stage of a more comprehensive
study, also including the tribological behaviour of various coatings on other support materials.
The paper describes the test stand together with the methods which have been
used and the experimental results obtained. These tests aimed to point out
the moment of transition from the elastic range to the elasto-plastic
range at the contact between the ball-shaped head and the sample. The
experimental tests shown that, on the two nickel-coated samples, the coated
layer presents almost the same tribological
characteristics up to a value of Hertzian pressure σk of about 2.200 Mpa.
Above this value,
on the sample with a nickel coated layer of 150 μm
in thickness, the plastic deformation process is intensifying.
D.C.:
669.24
Keywords:
superplasticity, strain rate sensitivity, strain rate, grain refinement,
thermomechanical processing.
Ana- Luciana
Rus: Superplasticity of Nickel-Base alloys
Metalurgia (56) 2004, nr.10, p.42
A number
of nickel-base alloys have been reported to exhibit superplasticity, and
tensile elongations have been observed in excess of 1000% in some cases. This
characteristic has stimulated the interest for the superplastic
forming process,
thereby providing alternatives to the more conventional but costly
fabrication methods
for the nickel-base alloys.. The paper reviews briefly the
nickel-base alloys, the superplastic properties of
these and the methods for grain refinement.
Ermina ŢAPU: Geometrical Shaping, the Base for
Designing the Shape of the Industrial Products
Metalurgia (56) 2004, nr.10, p.47
In the present paper it is described a
study that serves form identifying the influence that the geometrical form
has on the functional and aesthetic aspect of a product. In most of the
times, the geometrical spatial configuration of the systems represents the
base structure for sustaining the functional components and the final step in
defining this configuration is being made through the use of geometrical
shaping techniques and procedures.
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