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Z. Bonačić-Mandinić,
I. Budić, B. Solenički

The Influence of Moulding Sand on the Compressive Stresses
abstract, article page 17 - 22 pdf - 350 kB

M. Buršák,
I. Mamuzić,
J. Micheľ

The Influence of the Loading Rate on the Notch Tougness
of Light-Gauge Drawn Steel Sheets
abstract, article page 23 - 27 pdf - 250 kB

I. Uygur,
B. Gulenc

The Effect of Shielding Gas Compositions For MIG welding
process on Mechanical Behavior of Low Carbon Steel
abstract, article page 35 - 40 pdf - 145 kB

G. Sučik, T. Kuffa,
D. Hršak:
- The use of Diatomaceous Earth in Preparation of SiAlON Powder

M. Kupková, M. Kupka:
- Theoretical bounds on the electrical conductivity of sintered materials and their relation to bounds on the Young’s modulus

I. Štyriaková, I. Štyriak, T. Sasvar:
- Extraction of elements from sulphide and silicate concentrates by selected Bacillus isolates

T. Kuffa, G. Sučik,
D. Hršak:
- Investigation on the properties of pitch-bonded MgO materials

M. Cehlár:
- Management Technology of Wood Waste for Energetic Purposes

I . Lesso, J. Futo,
J.Krepelka,
A. Mockovčiaková:
- Control with Acoustic Method of Disintegration of Rocks by Rotary Drilling

M. Kundak, J. Črnko,
L. Lazić, M. Dazgić:
- Possibility of successful business making of welded steel tubes rolling mill in marketing conditions

Z. Bonačić-Mandinić, I. Budić, G. Solenički - The Influence of Moulding Sand on the Compressive Stresses

     The aim of this research is to explain how the distribution of moulding sand particles, apart from combination with other components (bentonite and water contents) affects the increase of compressive stresses in the moulding mixture. The granularity of sand and water content have great effect in the increase of compressive stresses. The regression analysis was used to obtain the mathematical model which describes the dependence of the compressive stresses on the mean size of the sand grains and water content in the mould mixture. pdf - 350 kB

I. Uygur, B. Gulenc - The Effect of Shielding Gas Compositions For MIG welding process on Mechanical Behavior of Low Carbon Steel

     The present study is focused on the mechanical properties of the deposited material which was extracted from welded region. This study explains the effect of the shielding gas composition on tensile behavior, R = - 1 fatigue response and various tempe-rature impact test results of MIG welded low carbon steels. In tensile tests, the stre-ngth values are increased with increase of CO₂ content, whereas the ductility is decreased. In the fatigue tests, the fatigue strength and the number of cycles to failure enhanced as the content of CO₂ increased. However, the impact toughness of the filler material is seriously influenced by the content of the shielding gas. An increase in CO₂ content caused significant decrease in toughness values at all temperatures. pdf - 145 kB

V. Goryany, I. Mamuzić,T. Hlyntseva, V. Radsinsky - Structure Formation in Strip Steel by Thermal Strengthening

     The results of research of microstructure of the strips from low carbon steel 45x6 and 30x8 mm in hot-rolling condition and after accelerated cooling of different intensity and schemes of the coolers movement in the cooling chambers are shown. A defind a temperature interval of phase transformations is in the cross-sections area of strips starting from axis of symmetry towards the edges. pdf - 220 kB

M. Buršák, I. Mamuzić, J. Micheľ - The Influence of the Loading Rate on the Notch Tougness of Light-Gauge Drawn Steel Sheets

     The paper assesses a possibility of implementing the notch toughness test on drawing sheets with the gauge up to 1 mm, the influence of the loading rate on the results, as well as a possibility of using this test to evaluate formability. Experiments were made on drawing steel sheets with a yield point from 145 to 250 MPa; the notch toughness test was made with the loading rates v₁ = 1.7·10^-5 ms^-1, v₂ = 5·10^-2 ms^-1 and v₃ = 4.8 ms^-1. The tests have shown that reproducible results can be achieved on light-gauge drawing sheets under defined conditions. The notch toughness values, as well as the force and deformation characteristics obtained in the notch toughness test can be used to supplement and make more exact the traditional characteristics in evaluating formability at increased sheet processing speeds, which are demanded in practice. pdf - 250 kB

J. Ďurove, M. Maras,
P. Vavrek, J. Daňko: 
- Stability Calculation of Underground Chambers Formed by Salt Leaching

J. Medved, V. Gontarev, L. Kosec, P. Mrvar - Internal Oxidation of the Cu-Se Alloys
     
      The purpose of our investigation was to perform the thermodynamic calculation of all possible reactions in the Cu-Se-O system and to explain the oxidation mechanism in various conditions. For such study, a model of copper with one single inclusion and alloy with 1.65 wt. % Se were made. Depending on time, the oxidation has been taking place at two different temperatures and two oxygen partial pressures. The oxidized samples have been investigated by DTA, optical and electron microscopy (SEM). pdf - 280 kB

M Oruč, R. Hadžalić - Phenomena of Ductility Minimum of CuZn28 Brass Bars which are Planned for Deep Drawing

     Effect of ductility minimum is common properties from most metals and alloys. Research which is presents in this work is in connection with occurrence of ductility minimum during the strain test of brass after rolling and then drawing at room and elevated temperatures. The occurrence of ductility minimum is connected to determined temperature and determined type of fracture which appears exclusive at that temperature. This conditions required to avoid this area for plastic deformation and chapping [1]. The tests of ductility on brass CuZn28 were done because that alloy has the highest ductility in a area comparing to other brasses [2]. Besides this, those tests were done because of problems which involve cold plastically deformation of rolled bars of brass CuZn28 (DIN 17660/84) which are planned for deep drawing. The problems were presented in the beginning of surface and under surface defect in the shape of vertical cracks on rolled and then on past drawn bars which were produced in semi-industrial factories of Metallurgical institute in Zenica. pdf - 190 kB

V. Grozdanić, A. Markotić - Three - Dimensional Mathematical Model of Fusion of Steel Scrap in the Converter Melt

     Three - dimensional mathematical model of fusion of cubical steel scrap in the converter melt was developed. The model was solved using modified implicit Brian’s method. The obtained algorithm was programmed in ASCII FORTRAN for the computer SPERRY 1106. In the model temperature dependent thermo-physical properties of material were incorporated. That gives to the model a nonlinearity. On the basis of the model it was concluded that addition of 1% of low - carbon steel scrap decreases the temperature of a middle carbon steel melt for cca 23 °C. This is in good agreement with experimental data from literature. At the same time a new formula for the fusion time of steel scrap was developed, which enables to calculate the fusion time on the basis of the volume of the steel scrap in the converter melt. pdf - 83 kB

M. Golja, M. Buršák - Flow Stress and Plasticity of Alloyed Steels

     This paper deals the results of investigation the flow stress of several various steel alloys and deformability by torsion test in hot condition in the temperature range 800 °C - 1250 °C on alloyed structural steels for special application. pdf - 101 kB

P. Baláž, A. Aláčová,
I. Mamuzić,
J. Ficeriová,
E. Godočíková,
M. Luxová:
- Mechanochemistry In Extractive Metallurgy and Preparation of Nanocrystalline Materials

I. Mamuzić - Croatian metallurgy - its Past, Present and Future

     This paper deals with the development of metalurgy in the world whose beginnings date 7 000 years B. C. On the teritory of today’s Croatia metalurgy has been present for 6 000 years. Three civilizations have left evidence: civilization of Vučedol, the Celtic and the Roman. After the arrival of the Croats to this teritory, metalurgy developed more intensively in the region of Sisak and Banovina as well as Samobor and Gorski Kotar. Bells and guns were cast in Dubrovnik and Zagreb. The industrial production started in 1853 (foundy in Rijeka) and in 1937 (the production of aluminium and Al-alloys in Lozovac) as well as with the construction of the blast furnace in Caprag in 1939.
     Today there are more than one company in Croatia whose technologies, compared with the technologies in worldwide companies are behind them more than 30 years. Unlike many European countries, that also as Croatia have no minimal raw material resources and nevetheless pay great attention to the development of their metallurgy, in Croatia this is no case. Al companies are being privatised, so the future Croatian metallurgy depends upon their owners, mostly foreigners. pdf - 305 kB

A. Begić, J. Malina, T. Matković - Comparison of corrosion characteristics of some dental alloys

     In this paper corrosion resistance of experimental dental Co-Cr-X (X = Mo, Ni) alloys, high purity titanium and Ag-amalgam was studied in Ringer’s solution. On the basis of electrochemical measurements, the relevant indicator of general corrosion jcorr, which is used for ranking of materials, was determined. It was found that commercial alloy Wironit® is the most stable material followed by pure titanium, Co-Cr-Mo and Co-Cr-Ni alloys, while amalgam showed the lowest resistance in the experimental conditions of model oral cavity medium. pdf - 170 kB

V. J. Kijac, P. Kováč, E. Steranka, V. Masek, P. Marek - The Current Status of Tundish Covering Slags in a Slab Caster Plant

     Tundish metallurgy development, which has been focused on steel cleanliness improvement in last few years, affected also tundish slag systems. Molten slags are the most suitable for both absorbing and refining functions of tundish cover slags, while a system of extremely low density does satisfy their isolating functions in the best way. Hence it is obvious, that it is not possible to assure the main functions using one sort of tundish covering slags. In addition, traditional acid slags, are being replaced with basic covering slags, or combination of both types. In this work, we have tried to investigate the operation of tundish covering slag under the condition of slab continuous casting. A genesis of covering slag from applied cover powders its refining functions have been investigated, as well as the changes of covering slag chemical composition during one tundish casting sequence. pdf - 115 kB