Wyniki wyszukiwania - BazTech

1

Evaluation of Influence of Briquetted Synthetic Slags on Slag Regime and Process of Steel Desulphurization

Socha L., Michalek K., Bažan J., Gryc K., Machovčák P., Opler A., Styrnal P.

Archives of Metallurgy and Materials

|

2014

|

Vol. 59, iss. 2

809--813

EN

This paper presents the industrial results of evaluation of efficiency of synthetic slags during the treatment of steel at the equipment of the secondary metallurgy under conditions of the steel plant VÍTKOVICE HEAVY MACHINERY a.s. The aim of the heats was to assess the influence of the briquetted and sintered synthetic slags based on AI2O3 aiming the course of the steel desulphurization and slag regime during the production and treatment of steel grade 42CrMo4 with the technology EAF→LF→ VD. Within the plant experiments, basic parameters influencing the steel desulphurization and slag regime were monitored: desulphurization degree, basicity, content of easily reducible oxides, proportion of CaO/AI2O3 and Mannesmann’s index. Obtained results allowed to compare the steel desulphurization and to evaluate the slag regime. It was proved that the synthetic slag presenting the briquetted mixture of secondary corundum raw materials can adequately replace the synthetic slag created from the sintered mixture of natural raw materials.

PL

W pracy tej przedstawiono przemysłowe wyniki oceny efektywności zastosowania żużli syntetycznych podczas obróbki pozapiecowej stali w zakładzie VÍTKOVlCE HEAVY MACHINERY a.s. Celem badań był a ocena wpływu brykietówanych i spiekanych żużli syntetycznych opartych na AI2O3 - na przebieg odsiarczania stali i żużla podczas produkcji i obróbki stali 42CrMo4. zgodnie z technologią EAF → LF → VD. Podczas eksperymentów w zakładzie, monitorowano podstawowe parametry wpływające na odsiarczania stali i żużla: stopień odsiarczania, zasadowość, zawartość tlenków łatwo redukowałnych, stosunek CaO/AI2O3 oraz indeks Mannesniann’a. Uzyskane wyniki pozwoliły na porównanie stopnia odsiarczania stali w kontekście zastosowanych żużli. Wykazano, że syntetyczny żużel składający się z brykietowanej mieszaniny wtórnego korundu, może zastąpić syntetyczny żużel otrzymywany ze spieku mieszaniny surowców naturalnych.

2

Evaluation of slag regime in ladle during utilization of briquetted synthetic slag in VHM a.s.

Socha L., Bazan J., Gryc K., Machovcak P., Opler A., Trefil A., Melecky J.

Archives of Materials Science and Engineering

|

2012

|

Vol. 57, nr 2

80--87

EN

Purpose: The paper focuses on evaluation of slag regime by the help of synthetic slags based on Al2O3. The comparion of influence of synthetic slags on the production of two chosen grades of steels focused on evaluation of effectivity of created refining slag during treatment in the secondary metallurgy was the objective of plant experiments. Design/methodology/approach:During evaluation of slag regime in the ladle, steel samples for assessment of desulphurization degree were taken under the plant conditions. Slag samples were also taken for evaluation of chosen parameters: basicity, content of easily reducible oxides, proportion of CaO/Al2O3 and Mannesmann’s index. The temperature and oxygen activity in steel was continuously measured too. Findings: From plant experiments, it was found out that during using of two different types of synthetic slags during production of steel grades St52-3 and S34MnV similar values of desulphurization degree were achieved. Chosen parameters of ladle slag were monitored and it was demonstrated that the developed synthetic slag B reaches the results comparable with the standard used synthetic slag A. Research limitations/implications: Plant experiments were made under conditions of VÍTKOVICE HEAVY MACHINERY a.s. plant Obtained results are limited by the testing during production of two different steel grades St52-3, S34MnV and by the specific technology of production formed by EAF→LF→VD/VCD. Practical implications: The research results made it possible to realize the optimalization of slag regime under the plant conditions of VÍTKOVICE HEAVY MACHINERY a.s. plant. It was proved that developed synthetic slag B from the company JAP TRADING s.r.o. can adequately replace the common synthetic slag A. Originality/value:Results mentioned in this paper are intended for steel producers and they represent basic information about possibilities of slag regime optimalization in the ladle.

3

Evaluation of chemical heterogeneity of a 90-ton forging ingot

Machovcak P., Opler A., Carbol Z., Trefil A., Merta K., Tkadleckova M., Michalek K.

Archives of Materials Science and Engineering

|

2012

|

Vol. 58, nr 1

22--27

EN

Purpose: This article describes performance of the experimental 90-ton forging ingot casting, the way of cutting, the methodology of chemical analysis and the results of that investigation. Design/methodology/approach: The experimental ingot 8K91SF weighing almost 90 tons was cast due the performance a detailed analysis of the current state of casting and solidification. The ingot was cut and macrostructure and chemical heterogeneity of the ingot was evaluated in detail. The standard method used in metallurgical analytics - analyses using optical emission spectrometers - was not applicable due to the large number of required analyzes. Thus, the mobile optical spectrometer SPECRTOTEST was used. Sulfur prints and fluid penetration tests were performed due to detect macroscopic distribution of sulfur and to locate surface-breaking defects. Findings: Current level of segregations of selected elements in real 90-ton steel ingot was detected. Also mutual mixing of two heats needed for the production of this ingot was verified. Research limitations/implications: Future research is focused on determination of inclusion content in selected parts of experimental ingot and on the level of micro-segregations. We are limited by the accuracy of chosen analytical method, which is also discussed in the paper. Practical implications: The gained knowledge is used to specification of the setting of boundary conditions of the numerical simulations, which should help to optimize the production technology of casting heavy forging ingots and minimize the level of segregation in ingots. Originality/value: New knowledge concerning mutual mixing of two heats needed for bottom casting of heavy forging ingot are presented in this paper. Distribution of segregation in so heavy ingot was detected. Results are the base for further investigations in macro-segregations and for the improving the accuracy of results of numerical simulations.

4

The utilisation of ferrous by-products contaminated by sulphur in the electric arc furnace charge

Krayzel M., Carbol Z., Korbas M., Sedenka D., Opler A., Richter T., Raclavsky M.

Prace Instytutu Metalurgii Żelaza

|

2006

|

T. 58, nr 4

121-124

EN

During the iron and steel-making processes iron-bearing waste, except the main product, is produced. It is characterised by diversity and the changing share of ballast substances as well as high sulphur content. For this reason recycling of this iron bearing material is very difficult. In steelmaking shop of VHM, J.S.C. plant, shrink heads of ingots and casts and/or magnetically separated iron spills were utilised in EAF in the amount of 5 to 35% of charge weight. In this article, results and contents of elements after melting were compared and influence of utilisation on technological process in EAF and on secondary metallurgy treatment was discussed. The practical sulphur saturation of the applied slag was determined as well.

PL

W procesach produkcji żelaza i stali powstają między innymi odpady żelazonośne, charakteryzujące się ogromną różnorodnością i zmieniającym się udziałem substancji balastowych oraz wysoką zawartością siarki. Z tego powodu recykling takiego materiału żelazonośnego jest bardzo trudny. W stalowni zakładów VHM, J.S.C. utylizowano w piecu łukowym nadlewy wlewków i odlewów oraz/lub magnetycznie wyselekcjonowane wadliwe elementy żelazonośne w ilości 5 do 35% masy wsadu. W artykule porównano zawartości pierwiastków po roztopieniu oraz omówiono wpływ utylizacji na proces technologiczny w piecu łukowym oraz na obróbkę pozapiecową. Określono też praktyczne nasycenie siarką stosowanego żużla.