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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) special issue no. 7 romanian metallurgical foundation Scientific publishing house

romanian metallurgical foundation Scientific publishing house scientific board staff Professor NICOLAE AVRAM Ph. D. professor Scorţea Costin Ph. D Managing Director: Editor-in-chief: Professor Scorţea Costin Ph. D. editorial board: Prof. dr. eng. bejan Mircea Prof. dr. eng. cănănău nicolae Prof. dr. eng. GĂLUŞCĂ DAN GELU Prof. dr. eng. hepuţ teodor Prof. dr. eng. IONIŢĂ GHEORGHE Conf.dr. eng. TODERIŢA NEMEŞ Prof. dr. eng. MARIA NICOLAE Prof. dr. ing. Ripoşan Iulian Prof. dr. eng. samoilă Corneliu Prof. dr. eng. SCORŢEA COSTIN Prof. dr. eng. SIMITI IOAN VIDA Prof. dr. eng. SOFONEA GALAFTION Prof. dr. eng. Şaban Rami Manager Scientific Publishing House F.M.R.: eng. Florentina Brânduşa Scorţea

Contents Issn 1582 – 2214 El-Din H. Nasr: Effect of different processing regimes on microstructure and tensile properties “at< 250°C” of hot rolled low-carbon, high-silicon and manganese sheet steel ……………………………………………….. 3 Anişoara Ciocan, Lucica Balint, Balint Simion: Study for zinc removal of galvanized steel scrap......................... 17 Florentina Potecaşu, Potecaşu Octavian, Alexandru Petricǎ: The obtaining of superficial oxidized lead powder …… 21 Munteanu Sorin Ion, Ciobanu Ioan, Crişan Aurel: Research concerning the influence of some geometric factors on the solidification of bars with U section …. 25 Chichernea Florin: Compared study on the static breaking of cast steel part shrink heads – Fifth chapter ……….... 37 Ana Socalici, Erika Ardelean, Ana Josan, Ardelean Marius: Researches meant to improve the quality of alloy steel ingots …………………………………………………. 43 ROMAN Costantin, Aureliana Geta ROMAN: Achievements in the field of direct investments during the transition period ……………… 47 ? Press release ……………..…………………….…….................... I – IV ? New books, published by romanian metallurgical foundation… V-VI

abstract

metalurgia International, special issue, no.7/2005

D.C.: 620.826 El-Din H. Nasr: Effect of different processing regimes on microstructure and tensile properties “at< 250°C” of hot rolled low-carbon, high-silicon and manganese sheet steel Metalurgia International (vol. X), no.7, special issue, 2005, p. 3 Three different processing regimes of low carbon-high silicon and manganese steel were carried out for producing high strength hot rolled sheets with high ductility. According to the cycle used, three different hot rolled steel groups were produced. The multiphased microstructure mainly consisting of polygonal ferrite, bainitic ferrite and 11.5 vol. % retained austenite (gr) of 1.3% carbon content shows the optimum tensile properties due to the a transformation induced plasticity “TRIP” effect of gr. A tensile strength of 821 MPa and a ductility of ~30% could be obtained at strain rate of 1.4 x 10^-4 s^-1. At elevated testing temperature, the steel groups are susceptible for dynamic strain aging with no measurable plastic strain preceded the appearance of serrations. Reducing strain rate has the same effect as increasing temperature in causing the aging. While the steel group exhibiting TRIP effect indicates decreases in ductility of < 12% and increases of < 11% in tensile strength due to dynamic strain aging, slight increases in tensile strength < 4% are shown for the microstructure containing iron carbide particles. This is due to the low amount of carbon in the interstitial positions, most of carbon is combined with iron. D.C.: 669.687 Anişoara Ciocan, Lucica Balint, Balint Simion: Study for zinc removal of galvanized steel scrap Metalurgia International (vol. X), no.7, special issue, 2005, p. 17 Today, the bodies of the most vehicles are made from galvanized steel. The zinc-coated layer protects the vehicles from corrosion during its life. At the end of the life cycle, steel scrap recovered by melting for steelmaking causes environmental problems and difficulties in the production of the steel. For obtained the clean steel scrap, an efficient dezincing process for galvanized steel has been studied. Based on the thermodynamically data, the use of air and chlorine mixture for dezincing steel scrap is presented in this paper. D.C.: 669.018.25 Florentina Potecaşu, Potecaşu Octavian, Alexandru Petricǎ: The obtaining of superficial oxidized lead powder Metalurgia International (vol. X), no.7, special issue, 2005, p. 21 The paper presents some results on the preparation of superficial oxidized lead powder by air jet spraying. The lead powder is compact, oval or spherical shaped, of clean pore free surface. The particles are covered with a thin oxidized film, as they have resulted from direct impact of lead powder with the air jet. By keeping constant the powder making parameters,

and the oxide film thickness too, the amount of oxidated powder can be indirectly varied by choosing types of grain powder belonging to finer grain classes. D.C.: 621.746.62 Keywords: casting, solidification, grey cast iron Munteanu Sorin Ion, Ciobanu Ioan, Crişan Aurel: Research concerning the influence of some geometric factors on the solidification of bars with U section Metalurgia International (vol. X), no.7, special issue, 2005, p. 25 In this paper it was studied, by computer simulation, the solidification of some bars in shape of U, cast in cast iron. In that scope it was used a 2D software created by authors. It was analysed the influence of the distance between parallel arms of the U profile on the position of hot spots and on solidification time. It was established the influence of the distance between the parallel arms of the profile on the coefficient of shape that characterise the solidification. D.C.: 621.746.464.; 539.4.011 Keywords: modelling, the static break, running, feeding, cast steel Chichernea Florin: Compared study on the static breaking of cast steel part shrink heads – Fifth chapter Metalurgia International (vol. X), no.7, special issue, 2005, p. 37 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 gatings and shrink heads, as well as on the modelling of breaking generating strains. D.C.: 621.785 Ana Socalici, Erika Ardelean, Ana Josan, Ardelean Marius: Researches meant to improve the quality of alloy steel ingots Metalurgia International (vol.X), no.7, special issue, 2005, p. 43 The paper introduces the researches and experiments on the possibility of improving the quality of alloy steel meant for ingot casting, in view of forge processing. Some of the flaws that appear in the ingot or in the forged products are the result of the production and casting processes and this is the reason why we analyzed the influence of the hydrogen contents on the alloy steel ingots. D.C.: 338.063.5 ROMAN Costantin, Aureliana Geta ROMAN: Achievements in the field of direct investments during the transition period Metalurgia International (vol.X), no.7, special issue, 2005, p. 47 Taking into account the importance of direct foreign investments for the process of restructuring and transition to the market economy, the authors present some interesting aspects in this field.