The influence of ferrous scrap’s grade on the yield of steel smelted in an electric-arc furnace (EAF)

In the paper there is presented a statistical analysis of the influence of various quality classes and the amount of scrap in steel charges on the rate of liquid steel yield from the electric arc furnace (EAF). The research methodology involved the analytical simulation of changes in the liquid mass of steel acquired from melts with different scrap content and statistical analysis of data obtained from the correlating process documentation (so-called melting sheets) under industrial conditions. The attained results may be employed in any steel mill that uses electrical steelmaking processes, to design the composition of a metal charge while bearing in mind the qualitative and economic aspects

Filtration of liquid uphill casted steel

The results presented in this paper are the next planned stage of research on the process of steel refining from dispersoid non-metallic phase by means of its filtration. Currently, the research has been focused on the process of casting steel using the traditional uphill method. This paper analyzes the prepared and conducted experiments on a semi-industrial scale with the use of multi-hole ceramic filters. The acquired results of macro and microstructure anlyzes, as well as steel cleanliness before and after the filtration process, reflect the course of the research and attest that it can be an effective and cheap method of refining it from non-metallic inclusions

Filtration of liquid uphill casted steel

The results presented in this paper are the next planned stage of research on the process of steel refining from dispersoid non-metallic phase by means of its filtration. Currently, the research has been focused on the process of casting steel using the traditional uphill method. This paper analyzes the prepared and conducted experiments on a semi-industrial scale with the use of multi-hole ceramic filters. The acquired results of macro and microstructure anlyzes, as well as steel cleanliness before and after the filtration process, reflect the course of the research and attest that it can be an effective and cheap method of refining it from non-metallic inclusions

The influence of slenderness of ceramic filters on the efficiency of steel refining

The results presented in this paper are the next planned stage of research on the process of steel refining from dispersoid non-metallic phase by means of its filtration. The acquired results of macro and microstructure anlyzes, as well as steel cleanliness before and after the filtration process, reflect the course of the research and attest that it can be an effective and cheap method of refining it from non-metallic inclusions. Presented results confirm that the slenderness of a filter has a significant impact on the effectiveness of the steel filtration process. Products of deoxidation have been identified on the filtration surface of ceramic filters

Microscopic investigations of axial zones of continuous casting ingots

This paper presents the results of microscopic investigations of the structure and chemical composition of the axial zones of continuous casting ingots of 140 x 140 mm cross-section made of G3Si1 steel, comprising the areas of porosityand axial shrinkage defects. The occurrence of shrinkage hollows and non-metallic phase, resulting from chemical reactions of the steel components with oxygen at the solidification front, has been stated in these areas

The influence of slenderness of ceramic filters on the efficiency of steel refining

The results presented in this paper are the next planned stage of research on the process of steel refining from dispersoid non-metallic phase by means of its filtration. The acquired results of macro and microstructure anlyzes, as well as steel cleanliness before and after the filtration process, reflect the course of the research and attest that it can be an effective and cheap method of refining it from non-metallic inclusions. Presented results confirm that the slenderness of a filter has a significant impact on the effectiveness of the steel filtration process. Products of deoxidation have been identified on the filtration surface of ceramic filters

Model investigations 3D of gas-powder two phase flow in descending packed bed in metallurgical shaft furnaces

This paper presents the second phase of model investigations of static pressure radial distribution conducted on 4 levels of bed height. During the phase the diameter of glass bed particles was increased, blast-furnace pellets were introduced as bed and iron powder was used as powder. Experiments were carried out with regard to gas velocity, bed and powder type and size of bed particles. The radial distribution of 3 fractions of powder accumulated in the bed – static powder, dynamic powder and total powder was calculated from experimentally obtained values of radial distribution of static powder. The influence analysis of the change of investigated bed and powder parameters on values of interaction forces between flow phases as well as on phenomena occurring in the system was conducted

Industrial investigations of the liquid steel filtration

Hitherto existing investigations concerning the ceramic filter use in the steel making processes have given good results. The obtained results of filtration have proved that this method may be used as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location considering the limitation of the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters

Determination of solidus and liquidus temperatures for S34MnV steel grade by thermal analysis and calculations

The paper is devoted to the comparison of the results in the frame of solidus and liquidus temperatures obtained by thermo analytical methods with the generally used empirically based formulas and thermo dynamical Computherm software. The series of thermal analysis measurements of high temperature phase transformations of real steel grade (S34MnV) under conditions of two analytical devices (Netzsch STA 449 F3 Jupiter; Setaram Multi High Temperature Calorimeter (MHTC)) were carried out. Two thermo analytical methods were used (DSC and Direct Thermal Analysis). The different weight of samples was used (2,6 g; 23 g). The liquidus and solidus temperatures for close to equilibrium conditions during heating (DSC: 1 °C/min; 2 °C/min) and during cooling (Direct Thermal Analysis: 1 °C/min) were determined and compared. Then, the discussion on the different values obtained by experiments and empirically based calculation is realised

Acute Exercise Increases Adiponectin Levels in Abdominally Obese Men

Objective. To examine the effect of acute and short-term (~1 week) aerobic exercise training on plasma adiponectin levels in inactive, abdominally obese men. Materials and Methods. Inactive and abdominally obese men (n = 38, waist circumference ≥102 cm) recruited from Kingston, Canada were randomly allocated to perform three bouts of aerobic treadmill exercise at either low (50% VO2 peak) or high (75% VO2 peak) intensity during a 1-week period. Blood samples were taken before and after the first exercise session and 24–72 hours following the completion of the final exercise session. Results. Adiponectin levels were elevated immediately following an acute bout of exercise at both high and low intensities (High: 5.79 ± 0.42 versus 5.05 ± 0.41 ug/mL; Low: 5.24 ± 0.44 versus 4.37 ± 0.44 ug/mL, P < 0.05) and remained elevated following 30 minutes of rest. In comparison to baseline, adiponectin levels were also elevated 24–72 hours following the final exercise session (High: 5.47 ± 0.48 versus 4.88 ± 0.48 ug/mL; Low: 5.18 ± 0.49 versus 4.47 ± 0.49 ug/mL, P < 0.05). Conclusion. Both acute and short-term aerobic exercise result in a significant increase in plasma adiponectin levels in inactive, abdominally obese men independent of intensity