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1
Content available Development of New Water Deoxidization Systems for Heat and Power Plants
Shabliy Tetyana, Gomelya Mykola, Pohrebennyk Volodymyr, Ivanenko Olena, Nosachova Yuliia
Journal of Ecological Engineering
|
2022
|
Vol. 23, nr 1
193--205
EN
The analysis of water conditioning methods for closed water supply systems was carried out in the work. The expediency of using redoxites based on ion exchange materials to combat the corrosion processes in water recirculation systems by preliminary deoxidation of water was shown. Modified KU-2–8, Dowex Mac-3, AB-17–8, Dowex Marathon WBA, AMBERLITE IRA 96 ion exchange resins were used as deoxidizing materials.
2
Content available Non-wetting to Wetting Transition Temperatures of Liquid Tin on Surfaces of Different Steel Samples Corresponding to their Spontaneous Deoxidation
Varanasi D., Aldawoudi K. E, Baumli P., Koncz-Horvath D., Kaptay G.
Archives of Metallurgy and Materials
|
2021
|
Vol. 66, iss. 2
469--476
EN
The goal of this paper is to measure the non-wetting to wetting transition temperatures of liquid tin on surfaces of different steel samples in vacuum with residual pressure of 10-8 bar. The experiments were conducted on four steels (C45, S103, CK60 and EN1.4034) of varying compositions using pure tin (99.99%) by the sessile drop method. Non-wetting to wetting transition (contact angle decreasing below 90°) by liquid tin was observed as function of increasing temperature in the range of 820-940 K for low alloyed steels C45, S103 and CK60, while it was considerably higher (around 1130 K) for high chromium EN1.4034 steel. it is concluded that at about the same temperatures, the surfaces of the steel samples are spontaneously deoxidized due to the combined effect of high temperature, low vacuum and C-content of steels. After the oxide layer is removed, the contact angles of liquid tin on steel surfaces were found in the range of 45-80° for low alloyed C45, S103 and CK60 steels and around 20° for high chromium EN1.4034 steel. These relatively high contact angle values compared to other metal/metal couples (such as liquid Cu on steels) are due to the formation of not fully metallic intermetallic compounds (FeSn and FeSn2) at the interface (such do not form in the Cu/Fe system).
3
Content available Optimisation of the technology of smelting and refining of steel into hot rolled sections on an innovative production line
Michałowski Mirosław, Klusek Stanisław, Dudkiewicz Piotr, Kamiński Paweł, Mandziak Sylwia, Adamczyk Mariusz, Różański Piotr, Szypuła Ireneusz, Zdonek Bogdan, Żak Artur
Journal of Metallic Materials
|
2019
|
Vol. 71, no. 1
10--19
EN
Experimental investigations have been carried out to optimise the secondary steel treatment technology in a ladle in order to ensure the required quality of steel intended for hot rolling of sections on an innovative line, with a reduced number of rolling stands characterised by a higher intensity of plastic processing. Experimental heats were made according to various steel deoxidation variants during secondary treatment and continuous casting of two steel grades. Continuous ingots were used to hot roll sections of various cross-sectional sizes. Based on the results of metallurgical, microscopic and mechanical tests of the sections, guidelines for the optimal continuous ingot production technology for hot rolling of sections on an innovative production line were developed.
PL
Przeprowadzono badania doświadczalne nad optymalizacją technologii pozapiecowej obróbki stali w kadzi w celu zapewnienia wymaganej jakości stali przeznaczonej do walcowania na gorąco kształtowników w innowacyjnej linii, przy zmniejszonej liczbie klatek walcowniczych, charakteryzującej się większą intensywnością przerobu plastycznego. Wykonano doświadczalne wytopy według różnych wariantów odtleniania stali w czasie pozapiecowej obróbki i ciągłego odlewania dwóch gatunków stali. Z wlewków ciągłych odwalcowano na gorąco kształtowniki o różnej wielkości przekroju poprzecznego. Na podstawie wyników badań metaloznawczych, mikroskopowych i właściwości mechanicznych kształtowników opracowano wytyczne do optymalnej technologii produkcji wlewków ciągłych do walcowania na gorąco kształtowników w innowacyjnej linii produkcyjnej, z wyeliminowaniem drutu Al wprowadzanego do krystalizatora w procesie ciągłego odlewania stali.
4
Content available Pomiar zawartości gazów w kąpieli metalowej drogą do optymalizacji zabiegów odtleniania i modyfikacji staliwa na odlewy
Kuder Mieczysław, Żyrek Adam, Bitka Adam, Uhl Waldemar
Journal of Applied Materials Engineering
|
2019
|
Vol. 59, no. 4
183--197
PL
W artykule przedstawiono wyniki prac nad optymalizacją procesu wytopu staliwa na odlewy armaturowe w piecu indukcyjnym o wyłożeniu kwaśnym. Do realizacji zabiegów odtleniania i modyfikacji używano materiały zawierające pierwiastki o wysokiej aktywności, jak: Al, Ca, Ti, Zr, Ce, V i Nb. Parametry tych zabiegów zostały ustalone na podstawie wyników prowadzonych pomiarów i oznaczeń zawartości tlenu, azotu i wodoru na różnych etapach prowadzonego procesu. Jakość staliwa oceniano w oparciu o wyniki badań metalograficznych, wytrzymałości i udarności w niskich temperaturach. Stwierdzono, że pomiary zawartości wodoru i aktywności tlenu w ciekłym stopie umożliwiają identyfikację zagrożeń procesu metalurgicznego, opracowanie optymalnych parametrów zabiegów odtleniania i modyfikacji, stabilizację właściwości mechanicznych i uniknięcia powstania wad wewnętrznych typu gazowego w odlewach.
EN
The paper presents the results of works concerning the optimisation of the process of steel melting for castings of industrial fittings in an induction furnace with an acid lining. Materials containing high activity elements such as Al, Ca, Ti, Zr, Ce, V and Nb were used for deoxidation and modification. The parameters of these procedures were determined on the basis of the results of measurements and determinations of oxygen, nitrogen and hydrogen content at various stages of the process. The quality of cast steel was evaluated on the basis of metallographic, tensile and low temperature impact strength test results. It was found that the measurements of hydrogen content and oxygen activity in the liquid alloy allow for the identification of hazards of the metallurgical process, the development of optimal parameters of deoxidation and modification procedures, the stabilisation of mechanical properties and the avoidance of internal gas type defects in castings.
5
Content available Influence of Process Parameters on Ceroxide Formation in Low-Carbon Steels
Vaucheret A., Nicolini C., Carton J.-F., Jacquet P.
Journal of Casting & Materials Engineering
|
2017
|
Vol. 1, no. 4
90--96
EN
Ceroxides are surface defects caused by a mold-metal reaction during the casting process of steels. This type of defect may affect a large area, but it is located only on the skin of the parts. It does not affect the core of the parts nor its mechanical properties. Nevertheless, ceroxides induce a lack of material on the surface, forming a kind of crater and needing complementary surfacing. The defect is also composed by several non-metallic inclusions containing Al, Mg, Si and O. An EDX analysis by mapping show these elements involved in the mold-metal reaction. The presence of these oxides could confirm the hypothesis of the deoxidizer reoxidation found in the bibliography. To better understand the specific conditions of ceroxide formation, the first step was to find of way to generate systematically this defect at each casting. Two patterns with different filling rate were designed, simulated on Quikcast and tested. The pattern with turbulent filling rate allowed the formation of ceroxide at each casting and so was used during this study. This result shows that the filling rate of the mold could be considered as a first order parameter in ceroxide formation. Then, a specific experimental set up was designed to characterize this defect. The analysis of the defect was done for sizing it: surface and depth. Finally, some key parameters on defect formation were determined like the nature of deoxidizer or the amount of oxygen in the mould. Some laboratory tests were lead to show the influence of these parameters by characterization of the casted parts in comparison with a reference sample. This study allowed us to find process parameters responsive of ceroxide formation and to propose some way of improvement to reduce the size and the occurrence of ceroxides.
6
Content available Deoxidation Impact on Non-Metallic Inclusions and Characterization Methods
Nicolini C.
Journal of Casting & Materials Engineering
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2017
|
Vol. 1, no. 4
97--102
EN
Deoxidation is an unavoidable step in the elaboration of steel. The study of its influence could improve the quality of low-carbon steel (0.20–0.25 wt.% of carbon). There are many deoxidation methods, and the most-common one consists of adding aluminum. Although it is a classic method, determining the optimal process parameters (quantity, yield, etc.) could be very sensitive. Deoxidation plays a determining role on inclusion cleanliness, especially on sulfide morphology. In order to control the efficiency of deoxidation, different techniques can be used. In this paper, an automated counting procedure on a scanning electron microscope with a field emission gun (FEG-SEM) is presented. This method was applied on samples cast in our laboratory under different deoxidation conditions. According to this, the resulting inclusion population is correlated with the aluminum content to find the optimal process parameters.
7
Content available Changes in Hydrogen Content During Steelmaking
Vrbek K., Lamut J., Marolt M., Knap M.
Archives of Metallurgy and Materials
|
2015
|
Vol. 60, iss. 1
295--299
EN
Štore Steel produces steel grades for spring, forging and engineering industry applications. Steelmaking technology consists of scrap melting in Electric Arc Furnace (EAF), secondary metallurgy in Ladle Furnace (LF) and continuous casting of billets (CC). Hydrogen content during steelmaking of various steel grades and steelmaking technologies was measured. Samples of steel melt from EAF, LF and CC were collected and investigated. Sampling from Electric Arc Furnace and Ladle Furnace was carried out using vacuum pin tubes. Regular measurements of hydrogen content in steel melt were made using Hydris device. Hydrogen content results measured in tundish by Hydris device were compared with results from pin tube samples. Based on the measurement results it was established that hydrogen content during steelmaking increases. The highest values were determined in tundish during casting. Factors that influence the hydrogen content in liquid steel the most were steelmaking technology and alloying elements.
PL
Stalownia Štore Steel produkuje gatunki stali sprężynowych, stali do kucia oraz stali do innych zastosowań przemysłowych. Linia technologiczna obejmuje elektryczny piec łukowy (EAF), rafinację pozapiecową w piecu kadziowym (LF) oraz maszynę do ciągłego odlewania kęsów (COS). Badaniom poddana została zmienność zawartości wodoru w stali w zależności od gatunku stali i wybranej linii technologicznej. Zgromadzono bazę danych w postaci próbek pobieranych z pieca łukowego, pieca kadziowego oraz maszyny COS. Próbki z pieca łukowego oraz pieca kadziowego pobierano za pomocą rurek próżniowych. Przeprowadzano regularnie pomiary zawartości wodoru w stali za pomocą urządzenia Hydris. Mierzoną zawartość wodoru w kadzi pośredniej za pomocą urządzenia Hydris porównywano z zawartością wodoru w próbkach pobranych za pomocą rurek próżniowych. Bazując na opisanych pomiarach stwierdzono wzrost zawartości wodoru w stali w czasie realizowanego procesu stalowniczego. Najwyższe zawartości stwierdzono w kadzi pośredniej urządzenia COS. Czynnikami mającymi największy wpływ na zawartość wodoru w ciekłej stali była zastosowana technologia wytapiania oraz pierwiastki stopowe.
8
Content available Contribution to Deoxidation of Austenitic Steels in a Vacuum Induction Furnace with Carbon
Šenberger J., Pernica V.
Archives of Foundry Engineering
|
2015
|
Vol. 15, iss. 2
105--109
EN
Deoxidation of steel with carbon under reduced pressure is often used for increasing the steel purity. Suitable units for this purpose in foundries are vacuum induction furnaces. Possibilities of increasing the steel purity by deoxidation with carbon in the vacuum induction furnace were studied for the steel for the petrochemistry of specific composition 25Cr/35Ni. The charge composed of the return material only was melted in the air. During melting the charge oxidized and the oxidizing slag formed. Chemical composition of steel, morphology, chemical composition of inclusions in the steel and chemical composition of slag after vacuuming were studied on the basis of samples taken before and after vacuuming. Temperature and oxygen activity were measured before and after vacuuming. Globular inclusions with dominant content of silicon and manganese were observed in steel before and after vacuuming. Contents of total oxygen in steel didn’t change significantly during vacuuming. On the basis of composition of inclusions and measured oxygen activity the activity of Cr2O3 in inclusions was calculated. A slag sample was taken after vacuuming and equilibrium oxygen activity in steel with regard to the Cr2O3 content in the slag was estimated from the slag composition. Equilibrium oxygen activity in relation to the Cr2O3 content in the slag was higher than equilibrium activity measured in the steel. For this reason it is not possible, under the studied conditions, to decrease oxygen content in steel during vacuuming.
9
Content available Numeryczna symulacja roztapiania drutów aluminiowych wprowadzanych do ciekłej stali
Borecki M.
Prace Instytutu Metalurgii Żelaza
|
2012
|
T. 64, nr 1
179-183
PL
Przedstawiono wyniki numerycznej symulacji roztapiania drutów aluminiowych wprowadzanych do ciekłej stali. Do obliczeń wykorzystano program Calco-MOS przeznaczony do symulacji ciągłego odlewania stali. Uznano, że proces ciągłego odlewania, czyli ciągłego krzepnięcia stali, jest odwrotny do procesu ciągłego roztapiania metalu, który ma miejsce podczas wprowadzania drutów do stali. W związku z tym program powinien dobrze modelować roztapianie drutów wprowadzanych do ciekłej stali. Właściwości termofizyczne niezbędne do obliczeń wyznaczono za pomocą programu JMatPro, a współczynnik wymiany ciepła między drutem, a warstwą zakrzepłej na nim stali wyznaczono eksperymentalnie korzystając z wyników doświadczeń laboratoryjnych i pomocniczego modelu numerycznego. Obliczenia wykonano dla drutów o średnicy 10 i 13 mm wprowadzanych do kadzi z różną prędkością w zakresie od 60 do 150 m/min w różnych temperaturach. Na tej podstawie wyznaczono czas i głębokość roztapiania się drutów w kadzi. Uzyskane wyniki porównano ze skutecznością odtleniania stali drutem aluminiowym, wprowadzanym do kadzi z różną prędkością w warunkach przemysłowych.
EN
The results of numerical simulation of melting the aluminium wires introduced into liquid steel are presented. For calculations the CalcoMOS software designed for simulation of continuous casting of steel was used. It was assumed that the process of continuous casting - or continuous solidification of steel is opposite to the process of continuous melting of metal, which takes place during the introduction of aluminium wires into liquid steel. Thus, the program should model the melting of aluminium wires introduced into liquid steel. The thermo-physical properties necessary for calculations were determined using JMatPro program and the coefficient of heat transfer between the wire and the solid steel layer on it was determined using the results of laboratory experiences and the auxiliary numerical model. The calculations were made for wires with diameters of 10 and 13 mm introduced into the ladle with different speed varying from 60 to 150 m/min and at different temperatures. Based on this, the time and depth of wire melting in the ladle were determined. The obtained results were compared to the effectiveness of deoxidizing the steel with aluminium wire introduced into ladle with different speeds under the industrial conditions.
10
Content available Influence of compound deoxidation of steel with Al, Zr, rare earth metals, and Ti on properties of heavy castings
Senberger J., Cech J., Zadera A.
Archives of Foundry Engineering
|
2012
|
Vol. 12, iss. 1
99-104
EN
Heavy steel castings deoxidized with aluminium are sometimes brittle intercrystalline failed during their service along primary grain boundaries what is initiated by aluminium nitrides and so called conchoidal fractures are formed. The tendency to forming the conchoidal fractures depends in particular on cooling rate (the casting modulus), aluminium and nitrogen contents in steel. During deoxidation, when manufacturing heavy castings, the elements with high affinity to nitrogen, zirconium or titanium, are added to steel that would decrease nitrogen activity by the bond on stable nitrides. The formation of stable nitrides should reduce the tendency of steel to the formation of conchoidal fractures. Deoxidation was thermodynamically analyzed at presence of the mentioned elements. For particular conditions a probable course of deoxidation was estimated at test castings. The deoxidation course was checked by microanalysis of deoxidation products (inclusions). For service and experimental castings the anticipated composition of inclusions was compared. It has been proved that in heavy castings with high aluminium contents in steel under studied conditions neither the addition of zirconium nor of titanium nor of rare earth metals will prevent the formation of conchoidal fractures.
11
Content available remote Checking the metallurgy with the aid of inclusion analysis
Senberger J., Zadera A., Cech J.
Archives of Foundry Engineering
|
2011
|
Vol. 11, iss. 1
118-122
EN
Results of studying the influence of inclusion morphology on properties of heavy casting are given. The inclusion morphology is dependent on content and kind of the deoxidizing element. Due to segregations the inclusions can be formed in heavy castings under different conditions (by concentration of deoxidizing elements) than in castings of common size. In heavy casting during deoxidation the inclusions of the IVth type occur more frequently. Deoxidation with zirconium shows to be for some heavy casting unsuitable one. Similarly in castings deoxidized with cerium and lanthanum the inclusions of greater sizes occur that can unfavourably influence the steel properties and increase the tendency to crack formation. The inclusion morphology after deoxidation with magnesium is also unsuitable for heavy castings.
12
Content available remote Wpływ procesu odtleniania i modyfikacji na udział i morfologię wtrąceń niemetalicznych staliwa węglowego
Kalandyk B.
Archiwum Odlewnictwa
|
2006
|
R. 6, nr 18/1
419--424
PL
Zaprezentowano wyniki badań ilości, morfologii i składu chemicznego wtrąceń niemetalicznych występujących w staliwie węglowym po wprowadzeniu do kadzi Al+FeCa-Si; Al+FeCa-Si +FeV lub Al+FeTi. Badania te przeprowadzono w warunkach przemysłowych. Stwierdzono, że najniższe zawartości wtrąceń otrzymano po podwójnym odtlenianiu Al +FeCa-Si i modyfikacji FeV.
EN
Influence of double deoxidations and modification of carbon cast steels on the morphology of non-metallic inclusions were studied. It was shown that the lowest inclusion content obtained by the initial desulphurization of steels and than its deoxidation by Al+FeCa-Si and modification by FeV (0,12%).
13
Content available remote Effect of the silica content in C12A7 and C3A1 inclusions on the variation of the mass ratio Ca/Al in calcium-treated steel
Kalicka Z.
Metallurgy and Foundry Engineering
|
2004
|
Vol. 30, No 1
13-21
EN
The mass ratios of the total calcium to aluminium contents, Ca/Al, in liquid steel in equilibrium state with calcium aluminosilicates C12A7-SiO2 and C3Al-SiO2 inclusions, i.e. 12CaO·7AI203 and 3CaO·Al2O3 inclusions containing some silica dissolved, were calculated. The Ca/Al value used to be a technologic criterion of alumina inclusions transformation into calcium aluminate CI2A7 accomplished by calcium treatment of steel with the purpose of decreasing of the total oxygen content and obtaining a good castability. Taking CI2A7 and C3A1 inclusions as the example it was found that silica dissolved in the inclusions decreases the value of Ca/Al ratio. The mass ratio Ca/Al is very sensitive to the chemical activity of oxygen in steel and temperature, and is altered as the floating-out of the inclusions follows. Although the Ca/Al data in steel containing C3A1 is generally much greater than in the one with C12A7 inclusions, one can conceive the steel conditions (oxygen activity, total aluminium content. temperature) when Ca/A data for steel with C3A1 inclusions will be nearly the same as for steel with C12A7 ones.
PL
Obliczono stosunek masowy całkowitych zawartości wapnia do glinu (tzw. Ca/Al) w stali zawierającej w warunkach równowagowych wtrącenia gliniokrzemianów wapnia C12A7-SiO2 oraz C3A1-Si02 tzn. wtrącenia 12CaO·7Al2O3 oraz 3CaO·Al2O3 z niewielką ilością rozpuszczonego dwutlenku krzemu SiO2. Wartość Ca/Al bywa traktowana jako technologiczny wskaźnik przekształcenia tlenku glinu w glinian wapnia C12A7 w celu uzyskania niskiej zawartości tlenu całkowitego oraz zapewnienia dobrej lejności stali. Na przykładzie wtrąceń C12A7 oraz C3A1 wykazano, że obecność w nich rozpuszczonego dwutlenku krzemu obniża wartość Ca/Al. Stosunek Ca/Al jest bardzo czuły na aktywność tlenu w stali i temperaturę oraz zmienia się w miarę wypływania wtrąceń. Mimo że w stali zawierającej wtrącenia C3A1 stosunek całkowitej zawartości wapnia do glinu jest zazwyczaj znacznie większy niż w stali z wtrąceniami C12A7, to mogą istnieć takie warunki (aktywność tlenu, zawartość glinu całkowitego, temperatura stali), że wartość Ca/Al w stali z wtrąceniami C3A1 będzie podobna jak w stali z wtrąceniami C12A7.
14
Model odsiarczania kąpieli metalowej w kadzi - obliczanie odtleniaczy i składników żużlotwórczych
Kawecka-Cebuka E., Pytel K., Karbowniczek M., Reichel J.
Hutnik, Wiadomości Hutnicze
|
2003
|
Vol. 70, nr 4
136--142
PL
Rafinacja kąpieli metalowej w kadzi decyduje o własnościach uzyskiwanej stali. Jednym z warunków jest uzyskanie zawartości siarki odpowiednim poziomie. W artykule zaproponowano model obliczania ilości materiałów odtleniających kąpiel metalową oraz dobc materiałów żużlotwórczych, zapewniających zakładany wysoki stopień odsiarczenia. Realizacja modelu odbywa się poprzez ustalei składu chemicznego żużla rafinującego w kadzi, cechującego się odpowiednią pojemnością siarczkową.
EN
Ladle rafination of steel determines properties of produced steel. One of required conditions is to obtain sulphur content at a adequate lex Calculation model of quantity of deoxidizers and slag forming additions for high desulphurization extent has been suggested. The moi allows to calculate the chemical composition of refining slag exhibiting adequate sulphide capacity.
15
Content available remote Udarność staliwa L15G w temperaturze -40oC
Ronatowski J., Głownia J.
Krzepnięcie Metali i Stopów
|
1998
|
nr 38
219--223
PL
Zbadano wpływ odtleniania i obróbki cieplnej staliwa L15G na jego udarność w temperaturze -40 i -60oC. Wykazano, że wymagane wartości udarności 40 J/cm2 można uzyskać tak po normalizowaniu jak i ulepszaniu cieplnym tego staliwa.
EN
This study demonstrates that deoxidation and heat treatment of cast steel L15G have effect on its impact toughness in -40 and -60oC. Is was found that value of 40 J/cm2can obtain after normalization or after quenching and tempering.
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