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METALLURGICAL AND ELECTROCHEMICAL BEHAVIOR OF S295 STEEL TUBES IN STEEL COOLING CIRCUITS

A.Bendjama, K.Morakchi, D.Berdjane, T.Chouchane, O.KHIREDDINE, H.MAHFOUD, S.CHETTOUH (2019)
Article de conférence

Corrosion damage to industrial cooling systems in steel mills is a serious problem for industry and the environment. In order to reduce this phenomenon by the subsequent development of organic-based corrosion inhibitors, a preliminary identification study of the base material and the surrounding environment of the cooling circuits is essential. To monitor the electrochemical behavior of unalloyed steel tubes, we studied the influence of the "industrial cooling water" environment and the most influential physical parameters. This behavior of S295 grade steel will be determined by different stationary and non-stationary electrochemical methods, notably electrochemical impedance spectroscopy. These investigations enabled us on the one hand the metallurgical knowledge of the base material, the nature of the corrosive medium, and on the other hand the evaluation of the potentials and the corrosion rates and to define the different reactions at the metal interface. middle. In conclusion, the tubes studied in unalloyed steel have a low resistance to corrosion under the effect of the aggressiveness of the surrounding environment (Figure 1) in this case industrial cooling water hence the need to introduce corrosion inhibitors in cooling circuits. In our case, we will focus on natural organic inhibitors that ensure an economic and environmental balance. Figure.1: Stationary and frequential electrochemical curves of the material / medium interactionVoir les détails

Mots clés : steel, corrosion, behavior, cooling water, impedance, Temperature

STUDY OF THE THERMAL AND MORPHOLOGICAL PROPERTIES OF SOLID STEEL WASTE

Ouahida Khireddine, Toufik CHOUCHANE, Amel Bendjama, Sana Chibani, Atmane BOUKARI (2019)
Article de conférence

Slags, by-products of the manufacture of pig iron in blast furnaces of the iron and steel industries. In recent years, the steel industry has put in place several ways of upgrading these materials, but these methods concern recent and homogeneous slags, which are still difficult to apply to ancient slags. These accumulations of non-reusable heterogeneous materials are left behind, and we must understand what impact they can have on their environment in the medium and long term. The main objective of this work is to carry out a study on the use of co-products from the El-Hadjar Annaba Algerian steel plant (blast furnace slags). This involves physico-chemical characterisation of appropriate methods, including optical microscopy, X-ray diffraction, infrared beam transformed spectrometry and thermal analysis. The diffractograms obtained on the slag samples characterise the vitreous phase and some light lines representing the crystallised compounds. Powder analysis by IR infrared spectrometry, Spectrum shows identified bands, such as Al-O, Ca-O, and Si-O bonds These results were justified by X-ray diffraction (XRD) and thermal analysis (ATG and DSC).Voir les détails

Mots clés : Slags, characterization, Steel waste, physicochemical properties

Effect of deformation on dry sliding wear behavior of 13Cr5Ni2Mo supermartensitic stainless steel

Samira. Tlili, Chems Eddine RAMOUL, Soumaya MEDDAH, Amel OULABASS (2019)
Article de conférence

During drilling, the tubings are subjected to tensile, compressive and torsional stresses. In this present work, the effect of deformation on wear of 13Cr5Ni2Mo SMSS in dry conditions is investigated using the tensile test. All samples were taken for the calibrated area of the 2%, 10% and 15% deformed specimens. The tribological tests were carried out at room temperature under a 6N against an alumina ball. The results showed that the deformed samples have the highest wear rate. Maximum wear rate was obtained for 2% deformed samples. This state can therefore affect the reliability of the material. The wear mechanisms involved were observed by scanning electron microscopy.Voir les détails

Mots clés : SMSS, mechanical properties, deformation, wear, friction

STUDY OF THE THERMAL AND MORPHOLOGICAL PROPERTIES OF SOLID STEEL WASTE

Slags, Characterization, Steel waste, physicochemical properties (2019)
Article de conférence

Slags, by-products of the manufacture of pig iron in blast furnaces of the iron and steel industries. In recent years, the steel industry has put in place several ways of upgrading these materials, but these methods concern recent and homogeneous slags, which are still difficult to apply to ancient slags. These accumulations of non-reusable heterogeneous materials are left behind, and we must understand what impact they can have on their environment in the medium and long term. The main objective of this work is to carry out a study on the use of co-products from the El-Hadjar Annaba Algerian steel plant (blast furnace slags). This involves physico-chemical characterisation of appropriate methods, including optical microscopy, X-ray diffraction, infrared beam transformed spectrometry and thermal analysis. The diffractograms obtained on the slag samples characterise the vitreous phase and some light lines representing the crystallised compounds. Powder analysis by IR infrared spectrometry, Spectrum shows identified bands, such as Al-O, Ca-O, and Si-O bonds These results were justified by X-ray diffraction (XRD) and thermal analysis (ATG and DSC).Voir les détails

Mots clés : Slags, characterization, Steel waste, physicochemical properties

Prediction of the fracture of a non-alloy steel calm to aluminum by simulation in direct tensile test

S. Achouri, R. Benchouieb, O.Ghalloudj, M. BOUREBIA, S. Medahhe, A. Oualabbas (2019)
Article de conférence

The mechano-probabilistic study is based on a set of statistical models allowing the understanding of the modes of fracture materials. In our case, we used the model of BORDET which has the distinction of being slightly complex and thin compared to other statistical models. This model takes into account the maximum principal stress at each moment and not the maximum main stress during loading. The Bordet model requires the knowledge of parameters intrinsic to the studied material (unalloyed steel killed with aluminum centered cubic structure). This work allows the optimization of the BORDET probabilistic model parameters; It defines a probability of rupture of the test pieces tested for the estimation of the durability of product. In our case the simulation test is done by quasi-dynamic tensile test for the extension to the cyclic tests.Voir les détails

Mots clés : modes of fracture, Mechano-probabilistic, BORDET

Bearing Fault Diagnosis of Induction Machine Based Empirical ModeDecomposition Energy and Entropy

Issam Attoui, Brahim OUDJANI, Nadir FERGANI, Nadir BOUTASSETA (2019)
Article de conférence

In this paper, according to the non-stationary characteristics of rotatingmachinery vibration signals, a method to the detection and classification of rollingelementbearing faults of induction machine using Empirical Mode Decomposition (EMD)Energy and Entropy is proposed. Firstly, the vibration signals are decomposed into afinite number of stationary intrinsic mode functions (IMFs), then the EMD energy andentropy are calculated. The analysis results from EMD energy and entropy of differentvibration signals show that these parameters will change in different frequency bandswhen bearing fault occurs. Therefore, to identify roller bearing fault class, the bestfeatures extracted from a number of IMFs that contained the most important faultinformation are selected using a wrapper algorithm that use the Adaptive Neuro-FuzzyInference System ANFIS classifier to evaluate subsets of features. The final features couldserve as input vectors of trained ANFIS. The analysis results from roller bearing signalswith inner-race , out-race and ball faults show that the proposed diagnosis approachbased on ANFIS by using EMD to extract the energy and entropy values of differentstationary intrinsic mode functions as features can identify roller bearing fault patternsaccurately and effectively.Voir les détails

Mots clés : EMD, Entropy, vibration signals, bearing Fault diagnosis

Study of Inhibitory Efficacy of Natural Extract of Opuntia Ficus Indica as Green Inhibitor for Corrosion of Mild Steel in Drilling Water

OULABBAS Amel, Achouri Sihem1, Meddah Soumaya1, Remichi Nasser1, Ramoul Chems Eddine1, TLILI Samira (2019)
Article de conférence

The purpose of this study is to evaluate the anti-corrosive effect of natural extract of Opuntia Ficus Indica (O.F.I) for X60 mild steel in drilling water environment used in petroleum engineering. Experimental work has been achieved by weight loss, potentiodynamic polarization and EIS measurement, as well as SEM surface characterization. Among the results obtained, we can mention an inhibitory efficientcy of 90% by gravimetric method and 80% by electrochemical method at 20% (v/v) of O.F.I.  Moreover, The O.F.I extract acts as a mixed inhibitor; however, adsorption free enthalpy indicates a physisorption. The adsorption obeys the Langmuir isotherm model.Voir les détails

Mots clés : corrosion, Mild steel, green inhibitor, Opuntia Ficus Indica and Electrochemical Impedance spectroscopy

Etude du pouvoir d’inhibition des terres rares contre lacorrosion des aciers bas carbone

A. Oulabbas, Y. Hamlaoui (2017)
Article de conférence

Afin de limiter la dégradation des aciers en service, des traitements de surface sontappliqués .L’association de différentes couches permet de protéger les matériaux contre lacorrosion de manière durable. Les composés à base de chrome hexavalent sont depuistoujours les plus utilisés dans le secteur aéronautique, car ils sont simples à mettre en oeuvre etsont reconnus comme étant les inhibiteurs les plus efficaces de la corrosion des aciers. Lesrécentes directives européennes précisent que l’utilisation des composés à base de chromehexavalent doit être réduite, voire supprimée, car ceux-ci ont été reconnus cancérigènes ettoxiques pour l’environnement. De nombreux travaux ont été réalisés ces dernières annéesmais, aujourd’hui, la plupart des solutions de substitution ne présentent pas le même niveaude performances que les procédés à base de chrome hexavalent. Un des traitements alternatifsde passivation utilise des oxydes de terres rares, notamment le cérium. L’utilisation ce derniercomme inhibiteur qui remplace le chrome hexavalent est caractérisé par la formation descouches minces est généralement associée à la formation d’oxydes ou d’hydroxydes decérium sur les sites cathodiques de la surface métallique. La caractérisation électrochimiquede ce procédé d’inhibition a été évaluée dans des milieux agressifs tels que NaCl 0.1 M,Na2SO4 0.1M et aussi une eau industrielle. Ainsi, la résistance à la corrosion obtenue surl’acier A 366 a été étudiée. Pour l’ensemble des échantillons, la durée de protection a étéévaluée grâce à la mesure de Ecorr. En parallèle, l’efficacité est suivie par la mesure de larésistance de polarisation, de la densité de courant de corrosion et aussi la spectroscopied’impédances électrochimique. En conclusion, les résultats des différentes techniquesélectrochimiques ont montré que le cérium peut très bien et avec une efficacité équivalenteremplacée le chrome hexavalent.Voir les détails

Mots clés : corrosion, chrome, cerium, impédance

The corrosion resistance ofsupermartensitic steels compared to martensitic steels in different corrosion media

A.Oulabbas S. Tlili, C.E. RAMOUL, S. Meddah, F. Sehab (2017)
Article de conférence

The supermartensitic stainless steels deduced from the refinement of the compositionof martensitic steels, have a low carbon content with 13% of chromium, 5% of nickel and 2%of molybdenum, this new generation of steel has an improved ductility with a good resistancemechanical and excellent resistance to corrosion. In this work, a comparative study of thecorrosion behavior of these two stainless steels in different aggressive chlorinated andsulphurized media was carried out. Stationary (polarization curves) and transient(electrochemical impedance) electrochemical methods have been applied. The rate ofcorrosion as a function of time was determined by the mass loss method and thecharacterization of the surface condition was studied by optical microscopy. Two types ofcorrosion were observed: uniform corrosion in which the half-reactions are homogeneouslydistributed in 0.5M H2SO4, followed by localized corrosion observed in 0.5M NaCl for bothsteels. According to the polarization curves, the corrosion potential differs betweenmartensitic steel and supermartensitic steel where it has a higher potential with -0.342 V / Ag/ AgCl in 0.5M H2SO4 and -0.339 V / Ag / AgCl in 0.5M NaCl. In parallel, the polarizationresistance given by EIS shows that in both media, supermartensitic steel is more resistant thanmartensitic steel where it has an Rp equal to 7200 Ohm in 0.5M H2SO4 and 8340 Ohm 0.5MNaCl. These results are confirmed by the optical microscope microstructure.Voir les détails

Mots clés : corrosion, martensitique stainless steel, supermartensitique stainless steel

L’Etude du comportement à la corrosiondes aciers inoxydables supermartensitiques et martensitiques dans deux milieux corrosifs

A. Oulabbas, S.Tlili, C.E. RAMOUL, S.Meddah (2018)
Article de conférence

l'objectif de notre travail est d'étudier la résistance que les aciers inoxydable martensitique et supermartensitique présentent lors d'une attaque à la corrosion chimique. pour cela deux milieux d'attaque le premier chloruré et le second sulfaté, sont utilisés comme électrolytes. la premiere approche éttant la technique de perte de masse suivit par l'étude du comportement électrochimique ( courbe de polarisation et impédance) d'aprés les courbes de polarisations , le potentiel de corrosion différe entre l'acier martensitique et supermartensitique, ou ce dernier présente un potentiel plus noble et cela dans les deux milieux. Voir les détails

Mots clés : acier martensitique, acier supermartensitique, impédance, corrosion