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Formation of Outburst Structure in Hot Dip Galvannealed Coatings on
IF Steels abstract, article page 9 - 14 pdf - 1545 kB

Dual Phase Ferrite-Martensitic Steel Micro-Alloyed with V-Nb
abstract, article page 15 - 20 pdf - 1322 kB

M. Kollárová, M. Džupon, A. Leško, Ľ. Parilák - Formation of Outburst Structure in Hot Dip Galvannealed Coatings on IF Steels

     Outburst structure in two industrially produced hot dip galvanized interstitial free steel sheets for automotive industry after additional annealing has been examined. Ti IF steel was found to form weak outburst structure in the early stage of annealing, followed by frontal growth of Fe-Zn phases during further heating. The high reactivity of this steel was confirmed by rapid G-phase formation. Under the same conditions, Ti-Nb-P IF steel exhibited frontal growth of Fe-Zn compounds without G-phase formation due to relatively high phosphorous content, which is known as inhibitor of Fe-Zn reaction, but simultaneously significant occurrence of undesired outburst structures was recorded. It was assumed that the phosphorous content was insufficient and/or ferrite grain was very fine. pdf - 1545 kB

J. Zrník, I. Mamuzić, S. V. Dobatkin, Z. Stejskal, L. Kraus - Low Carbon Steel Processed by Equal Channel Angular Warm Pressing

     Low carbon steel AISI 10 was subjected to a severe plastic deformation technique called Equal Angular Channel Pressing (ECAP) at different increased temperatures. The steel was subjected to ECAP with channel’s angle j = 90°, at different temperature in range of 150 - 300 °C. The number of passes at each temperature was N = 3. Light, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of thin foils were used to study the formation of substructure and ultrafine grains in deformed specimens. The size of newly born polygonized grains (subgrains and/or submicrocrystalline grains) is in range of 300 - 500 mm. The formation of such of predominant submicrocrystalline structure resulted in significant increase of yield stress [R_e] and tensile strength of the steel [R_m]. pdf - 2323 kB

Z. Zovko Brodarac, P. Mrvar, J. Medved, P. Fajfar - Local Squeezing Casting Influence on the Compactness of AlSi10Mg Alloy Castings

     The aim of the local squeezing casting process examination has been to eliminate the hot spot i.e. the place of potential formation of shrinkage porosity. The influence of variation of process parameters on the density i.e. soundness (compactness) of AlSi10Mg alloy castings has been obtained by the local squeezing process with the pin during gravity casting in the special permanent mould. Local squeezing parameters have been determined on the basis of preliminary investigations of AlSi10Mg alloy: temperature intervals and relevant temperature of singular phases precipitation and the microstructure development at different cooling rates. The temperature interval of performing the local squeezing casting process have been established in which the density values approaching to the theoretic ones have been determined. pdf - 2028 kB

V. Roubíček, P. Pustějovská, J. Bilík, I. Janík - Decreasing CO₂ Emissions in Metallurgy

    Modern trends in iron metallurgy. Global carbon emissions from iron production. New solution for iron and steelmaking in a way reduce the CO₂ emission to the level, where this might be needed in the post - Kyoto period. New blast furnace technology, which operate with very low CO₂ emissions based on drastically reduced consumption of carbon containing input materials. Injection of reducing gases and oils into the furnace. Injection of materials containing hydrogen permits material recycling and influencing the coke consumption of the blast furnace process. Direct reduction and eliminating CO₂ emissions in Iron metallurgy. Technologies and processes with CO₂ removal. Cost optimized CO₂ reduction. pdf - 1457 kB

R. Lenort, A. Samolejová - Analysis and Identification of Floating Capacity Bottlenecks in Metallurgical Production

    The article constitutes a procedure for the analysis and identification of floating capacity bottlenecks in metallurgical production. The procedure conceived is based on the use of detailed capacity calculations, the output of which is the determination of the hourly output of the floating capacity bottleneck depending on the production schedule. Applying the said procedure is illustrated by the example of output analysis of a line for the cutting of hot rolled bars. Analysis and identification of the floating capacity bottlenecks subsequently becomes the starting point for applying the principles and tools of the Theory of Constraints (TOC) in material flow control in metallurgical plants. pdf - 558 kB

J. Tušek, B. Taljat, D. Klobčar - How to Extend the Life of Die-Casting Tools

    The paper explores some possibilities of extending the life of die-casting tools for non-ferrous metals, particu-larly aluminium, magnesium, and their alloys. In the first part of the paper is shown theoretical background of the problem. The major part treats the tools: tool life, tool manufacture, tool certificate, tool operation and repair of tools by welding. Welding is the only technology fit for repair of tools and thus to extend their service life. In the paper is shown some welding processes, which are suitable for repair welding of tools. pdf - 1218 kB