http://arthra.ugal.ro/handle/20.500.14043/26044 Fri, 17 Apr 2026 02:59:11 GMT 2026-04-17T02:59:11Z http://arthra.ugal.ro/handle/20.500.14043/26059 Some Aspects Regarding the Influence of Tribologycal Factors on the Superficial Layers of Steels Treated with Plasma Nitriding Papadatu, Carmen Penelopi; Vasile, Elisabeta Some 38MoCrAl09 (SAE 4038) steel grade samples were subjected to plasma nitriding treatment regimes. The structural and diffractometric aspects of the superficial layers of the steel are studied after the wear tests by friction, using an Amsler type machine, taking two sliding degrees at different contact pressures and testing time. The tests were made to detect the sustainability to the material, the evolution of the superficial layer through different tests and to establish the influence of these tribological factors (operating parameters) on the superficial layers. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 4 – 2012, ISSN 1453 – 083X Sun, 01 Jan 2012 00:00:00 GMT http://arthra.ugal.ro/handle/20.500.14043/26059 2012-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/26058 Assessment of Blast Furnace slag Transformation Into value Added by-Products on Basis on Knowledge of Slag Characteristics Ciocan, Anișoara Slags are the main by-products generated during iron and crude steel production and the steel industry is committed to increasing and improving their recycling. Today the quantity of slag produced and its utilization are one of the important indicators of sustainable steel industry. There are different forms of BF slag by-products depending on the method used to cool the molten slag. The byproducts can be an excellent source of constructional materials, finding applications in road building, concrete aggregate, as thermal insulation (mineral wool), and as a clinker substitute in cement production, biological filter media, glass making etc. In addition to products obtained from fresh slag, the possibility to utilize the old and the stockpiled blast furnace slags was studied. A key role in their utilization plays the knowledge of the chemical, mineralogical, and morphological properties of BF slag. This paper summarizes the characteristics of BF slag and its possible application. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 4 – 2012, ISSN 1453 – 083X Sun, 01 Jan 2012 00:00:00 GMT http://arthra.ugal.ro/handle/20.500.14043/26058 2012-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/26057 Mathematical Modeling of the Heat Treatment Process Applied to Alloy Al-Zn-Mg-Cu-4.5% Zn, Used in Aeronautics Neacșu, Marian; Hanganu, Doru This paper presents mathematical modeling based on the regression analysis method by active experiment of a thermal treatment process applied to an alloy belonging to Al-Zn system, which finds application in aeronautics. Using the mathematical model determined on a statistical basis, we achieved the prediction of the mechanical properties studied by simulating the heat treatment process, more exactly by simulating the heat treatment parameter values within the experimental values. The mathematical model equations obtained in this paper can also be used to achieve the optimal values of the treatment technological parameters in order to obtain the desired complex of properties with minimum costs. The Annals of "Dunarea de Jos" University of GalatiFascicle IX Metallurgy and Materials Science N0. 4 – 2012, ISSN 1453 – 083X Sun, 01 Jan 2012 00:00:00 GMT http://arthra.ugal.ro/handle/20.500.14043/26057 2012-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/26056 Low Potential Heat Recovery Using Heat Pumps Tofan, Sorinel; Panait, Tănase This paper presents a study on the possibility of recovering low thermal potential heat from the cooling technological water of industrial processes. The analysed solution consists in the use of a heat pump which would send the recovered heat to a hot water flow. We started from a technological water flow which was taken over by a 350 m3/h cooling tower and we determined the performances of a heat pump when using various refrigeration agents, for a range of values of the temperature of hot water and the temperature of the return of technological water which varies according to season. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 4 – 2012, ISSN 1453 – 083X Sun, 01 Jan 2012 00:00:00 GMT http://arthra.ugal.ro/handle/20.500.14043/26056 2012-01-01T00:00:00Z