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Comprehensive Processing of Basalt together with Magnetite Concentrate in Order to Obtain Ferrous Alloy and Calcium Carbide

Shevko V. M., Karataeva G. E., Badikova A. D., Tuleev M. A., Uteeva R. A.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

41--54

EN

This article is devoted to basalt reprocessing together with magnetite concentrate in order to obtain ferrous alloy and calcium carbide. The studies have been based on thermodynamic simulation and electric smelting in arc furnace. The thermodynamic simulation has been performed using HSC-5.1 software based on the principle of minimum Gibbs energy. The blend was smelted in arc furnaces. On the basis of the obtained results of combined processing of basalt, it has been established that under equilibrium conditions, the increase in carbon content from 36 to 42 wt % of basalt and concentrate mixture makes it possible to increase the aluminum extraction into the alloy up to 81.4%, calcium into calcium carbide – up to 51.4%, and silicon into the alloy – up to 78.5% [...]

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Problems of phase identification in high-nitrogen chromium-manganese cast steel

Pirowski Z.

Archives of Foundry Engineering

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2008

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Vol. 8, iss. 1 spec.

281--284

EN

An attempt has been made to offer an interpretation of the microstructure of chromium-manganese cast Steel after adding to this steel a large amount of nitrogen as an alloying element. Nitrogen was added to the cast steel by two methods: the first method consisted in adding anitrided ferromanganese, the second method in remelting the nitrogen-free alloy under the atmosphere of nitrogen maintaining high N2 pressure above the metal melt (3,5 MPa). Some important differences in the microstructure of the examined cast Steel have been observed, depending on how the nitrogen was introduced to the alloy. When melting was carried out under the atmospheric pressure adding the nitrided ferroalloys, the matrix was composed of nitrided austenite, and numerous nitrides (carbonitrides) were forming a well-developed network along the grain boundaries. Melting of alloy under the high pressure of nitrogen enables obtaining much higher concentration of this element in metal. The network of precipitates along the grain boundaries is observed to exist no longer, and the lamellar structure occupies now practically the entire metal volume. When alloys are melted in the air, only small fragments of the lamellar structure, forming the, so called, “Chinese script” and local clusters are present. At this stage of the research, an attempt has been made to identify the phases in chromium-manganese cast Steel using a transmission electron microscope. The conducted studies partly confirmed the conclusions resulting from the examinations carried out previously under the optical microscope. So far, however, no consistent answer has been found to the question of what type are the precipitates present in the structure of the examined alloy. Attempts at further interpretation of the obtained results will be taken at the next stage of the work with attention focussed on the precipitates formed during the process of solidification of the examined chromium-manganese cast steel with an addition of nitrogen.

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Sterowanie procesem krzepnięcia odlewu w technologii modeli cieplnie zgazowywanych

Żółkiewicz Z., Żółkiewicz M., Jankowski W., Wilk J.

Archiwum Odlewnictwa

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2006

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R. 6, nr 18/2

219--224

PL

Przedstawiono problematykę związaną z zastosowaniem modeli polistyrenowych cieplnie zgazowywanych, formowanych w medium o różnej szybkości odprowadzenia ciepła krzepnącego i stygnącego staliwnego odlewu. Porównywano własności mechaniczne odlewu wykonywanego w masie składającej się z 100% piasku kwarcowego oraz mieszaninie piasku kwarcowego oraz śrutu żeliwnego. Formę wykonano z mieszaniny dwóch mediów o różnym wzajemnym procentowym stosunku wagowym. Tak wykonana masa formy charakteryzuje się różną prędkością przewodzenia ciepła oraz pojemnością cieplną. Starano się określić wpływ szybkości odprowadzenia ciepła z krzepnącego i stygnącego odlewu na jego własności mechaniczne oraz strukturę.

EN

Problems related with the application of evaporative polystyrene patterns placed in moulding media characterised by diffrent rate of heat transfer from the solidifying and cooling steel casting were discussed. Mechanical properties of casting made in mixture composed in 100% of the silica sand and in mixture composed of silica sand and cast iron shot were compared. The mould was made of two different media mixed in different percent ratios. Thus prepared moulding mixture was characterised by different heat conduction rate and thermal capacity. An attempt was made to determine the effect of heat transfer rate from the solidifying and cooling casting on its mechanical properties and structure.

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Ocena skłonności do umocnienia wybranych stopów żelaza pod wpływem naprężeń zewnętrznych

Pirowski Z.

Archiwum Odlewnictwa

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2006

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R. 6, nr 18/1

437--442

PL

W strukturze niektórych badanych stopów na bazie żelaza stwierdzono zmniejszenie się ilości austenitu pod wpływem zewnętrznych naprężeń rozciągających. Naprężenia te nie wpłynęły istotnie na umocnienie tych stopów, natomiast naprężenia ściskające znacznie te stopy umocniło. Zaobserwowano wzrost twardości nawet o około 40% w przypadku staliwa duplex z dodatkiem 0,4% azotu i żeliwa ADI.

EN

The structure of some investigated ferrous alloys shows the reduction in austenite content as a result of the applied external tensile stresses. The external stresses not significantly affecting on the strain hardening, whereas the compressive stresses hardened these alloys considerably. The increase in hardness even by about 40% was observed in duplex cast steel with the additions of 0.4% of nitrogen and in the case of ADI.