J. Črnko - Composition and Properties of TiO₂ Powder Got Hydrometallurgically

     Properties of TiO₂ powder got hydrometallurgically from the slag that was, together with pig iron, a product of reductional red mud electromelting were investigated using physico-chemical methods of analyzing. The samples of TiO₂ powder contain high quantity of titanium compared with the used raw material - granulated slag. Investigating the mophology of the powder samples, it has been found out that aggregation of particles and forming of bigger aggregates take place. They differ in form and size. A granulometric analysis of the powder determined a weight portion of the biggest aggregates in it, as well as its specific surface.

J. Micheľ, M. Buršák, I. Mamuzić - Creep Properties of Microalloyed Steels

     Paper analyses the properties of microalloyed steels quality of S315 MC and S460 MC and carbon heat resistance steel of quality St.45.8 at higher temperatures in the creep conditions. The higher values of stress-rupture strength of microalloyed steels in the creep conditions (400 - 500 °C), which are comparable to stress-rupture strength of low alloyed steels, are mainly the result of the precipitation hardening.

B. Piekarski, M. Garbiak - Effect of Nb and Ti on Microstructure and Mechanical Properties of 30% Ni / 18% Cr Cast Steel After Annealing

     The study discusses the microstructure and mechanical properties of eight tested 0.3 % C -30 % Ni - 18 % Cr cast steels stabilized with niobium and titanium after annealing in the cycle of 900 °C / 300 h. The niobium content in the cast steels varied from 0.0 to 2.0 % and that of titanium from 0.0 to 1.2 % by weight. Microstructure was examined using both light microscope and a scanning electron microscope with Link IS-IS attachement as well as an X-ray diffractometer. Depending on the chemical composition of cast steel, the following phases were identified: carbides of MC and M₂₃C₆ type and a phase rich in silicon, nickel, niobium and / or titanium, which was supposed to be a phase G. Relationships between the microstructure and mechanical properties of cast steel at 20 and 900 °C were examined as well.

J. Tušek - Narrow-Gap Submerged-Arc Welding With a Multiple-Wire Electrode

     The article treats a completely new variant of narrow gap welding. First, nine different welding heads for narrow gap welding are described and shown schematically. The core of the article is devoted to a description and schematic representation of a unit for welding with twin-wire and triple-wire electrodes respectively and a description of technology for narrow-gap submerged-arc welding of thick workpieces. A macrograph of the weld is shown too, and basic optimum welding parameters for attaining a quality weld are given. Finally, main advantages of multiple-wire narrow-gap submerged-arc welding are stated.

J. Tušek - Factors Affecting Weld Shape in Welding With a Triple-Wire Electrode

     The article describes the influences of welding parameters, modes of metal transfer through the arc and the number of wires applied on weld formation and final shape. Diagrams show the influence of current intensity and arc voltage while a figure shows the influence of streaming and rotating metal transfers on the final weld shape. Diagrams and macro specimens, however, show the influence of the number of wires used on the weld shape and weld formation in submerged arc welding with a triple-wire electrode.

V. N. Danchenko, I. Mamuzić, P. V. Drozhzha - Ingress of the Salt Lubricant on a Tube-Mandrel Contact in the Stands Continuous Mill of Tubes

     The mechnism of the salt phosphate lubricant ingress in zone of the tube deformation on a long cylindric mandrel was considered. Suggested mathematical model is based on the points of the hydrodynamic theory of lubrication. Data presented are concerned with a value of a salt lubricant layer thickness and friction factor between metal and mandrel at continuous hot rolling of tubes.

T. Kuffa - Improvement of Basic Carbon Refractories by Titanium-Based Antioxidant

     Possibility of the preparation of the titanium-based antioxidant from Ti-scrap materials. Thermodynamic conditions and theoretical aspects of its application in magnesia carbon bricks. Laboratory tests oriented on the efficiency of this application. The finger corrosion tests of bricks from different sorts of magnesia clinkers.

K. Kostúr, M. Laciak - Model for Indirect Measurements of Ld - Steelmaking Process

     This paper describes a statistical approach to modelling the LD-steelmaking process. The steelmaking process belongs to very complicated metallurgical processes, in which the measurement of process variables is very difficult and economically challenging. Among these variables are mostly the concentration of carbon in hot metal and the temperature of bath. Both of them are very important for predicting the end of blowing. We can obtain an appropriate prediction by using a simulation model of the technological process. We recognize several approaches to making simulation models and bave chosen the statistical approach which counts selected process variables from regression equation step by step. An advantage of using a regression model is that we can eliminate interruption of blowing.