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Diplomska naloga proučuje možnosti povezovanja društev zaradi racionalizacije delovanja društev. Naloga je razdeljena na teoretični in praktični del. V teoretičnem delu je najprej opredeljen pojem društvo, predstavljena je dejavnost društev, opisujemo predpise, ki urejajo računovodenje društev ter letna poročila in davčne obveznosti društev. V tretjem poglavju opisujemo računovodenje društev. V društvih se pojavlja tako računovodenje pridobitne dejavnosti, kot računovodenje nepridobitne dejavnosti. Zakon o društvih namreč določa, da mora društvo, ki opravlja pridobitno dejavnost, podatke o finančnem in materialnem poslovanju iz te dejavnosti voditi in izkazovati ločeno. Kot pravna oseba mora društvo predložiti pristojnemu organu DURS obrazec za obračun davka od dohodkov pravnih oseb, tudi kadar ne ugotovi davčne osnove. Za opravljanje dejavnosti je oproščeno le plačevanja davka od dohodka iz opravljanja nepridobitnega dela dejavnosti. Zadnje poglavje je namenjeno računovodenju v Športnemu društvu Studenci in Športnemu društvu Center Maribor. Predstavili smo obe društvi ter prikazali njihove računovodske izkaze. Iskali smo možnosti skupnega upravljanja sredstev društev. Izmed treh predstavljenih možnosti: spojitev društev in enotno računovodstvo, ustanovitev zveze društev ter ustanovitev podjetja, bi se odločili za prvo možnost, saj so prednosti z računovodskega vidika najbolj ugodne. This diploma paper discusses the possibility of clubs connecting with each other on account of rationalisation of clubs’ function. The paper is divided into theoretical and empirical part. At the beginning of the theoretical part there is a definition of the word club, presentation of clubs’ activity, we also describe regulations that regulate clubs’ accounting and annual reports along with the tax liability of the clubs. In the third chapter we describe clubs’ accounting. Both paid employment accounting as well as non-profit accounting of the activities is used in clubs. Societies act defines that the club performing paid employment activity, has to manage and issue its financial and material management separately. The club as a legal entity must submit a taxation form of the legal entities income to the Tax Administration of the Republic of Slovenia, even when the tax base is not determined. The only activities exempted from taxes on entrepreneurial profit are non-profit work activities. The last chapter is dedicated to the accounting in the Športno društvo Studenci and Športno društvo Center Maribor. We presented both clubs and their accounting records. We searched for options of collective management of clubs’ finances. Among three presented possibilities: union of clubs and unified accounting, establishment of the clubs’ federation and establishment of a company, we would choose the first for the most beneficial advantages in the accounting field.

The article describes the Internet survey, conducted for public health purposes, on the sexual behaviour of men who have sex with men (MSM). It describes the usefulness of qualitative surveys for research into the sexual behaviour of MSM in the context of the HIV/aids pandemic. The article expands the description of the social situation of MSM with a discussion of the importance the Internet has for their communication and for the research into sexual behaviour. It presents the results of the author's analysis of an open-end question on respondents' ideas of the best sex life and discusses the implications for public health efforts. Prispevek opisuje internetne raziskave spolnega vedenja moških, ki imajo spolne odnose z moškimi (MSM) za javnozdravstvene namene. Opiše uporabno vrednost kvalitativnih raziskav v preučevanju spolnega vedenja MSM v kontekstu pandemije HIV-a/aidsa. Opis družbene situacije MSM v Sloveniji nadgradi s pomenom, ki jo ima internet za njihovo komunikacijo in za raziskovanje spolnega vedenja. Predstavi rezultate analiz vprašanja odprtega tipa o tem, kakšne so njihove predstave o najboljšem spolnem življenju in razpravlja o implikacijah za javnozdravstvena prizadevanja.

Experiments into the swelling and foaming of synthetic iron oxide gangue melts prove that two basic prerequisites have to be met for the occurrence of these phenomena. Firstly there must be present within the specimens relatively large volume fractions of a liquid FeO-containing phase which come into contact with carbon. This leads to heavy gas formation. Secondly, slags of this type must exhibit a certain gas retention capability. In this respect, a precipitated iron support skeleton can be helpful. Medium-basic slags swell very well and over a relatively long period. Highly basic slag melts, following a brief period of swelling, are quickly resolidified by 2CaO.SiO 2 precipitation. In the case of acidic specimens, only a small or no volume increase is observed. Pure iron oxide melts undergo virtually no swelling whatsoever

Prost pretok gensko spremenjenih živil je v EU urejen z uredbami in direktivami. Države članice imajo zelo omejene možnosti, da bi na tem področju sprejemale drugačne nacionalne predpise. Zakonodajalec EU in Sodišče EU se trudita najti občutljivo ravnotežje med zahtevami po prostem pretoku blaga in varovanjem zdravja oz. varstvom potrošnikov. Pri sprejemanju predpisov EU je potrebno zasledovati dva cilja, in sicer prost pretok gensko spremenjenih živil in upoštevanje načela previdosti. Sodna praksa kaže, da Sodišče EU izjeme na področju prostega pretoka blaga razlaga zelo ozko in da države članice nimajo veliko možnosti, da bi te izjeme uveljavile v praksi. ZUSAMMENFASSUNG Der freie Warenverkehr von gentechnisch veränderten Lebensmitteln ist an der EU-Ebene mit den Verordnungen und den Richtlinien geregelt. Den EU-Mitgliedstaaten ist nicht viel Gestaltungsspielraum gelassen, um eigene Vorschriften in diesem Bereich zu entlassen. Der Gesetzgeber der EU und der Europäische Gerichtshof sind in der Suche nach empfindlichem Gleichgewicht zwischen dem freien Warenverkehr und dem Gesundheit- bzw. Verbraucherschutz mit einer überaus anspruchsvollen Aufgabe konfrontiert. Bei der Entlassung der Vorschriften der EU werden deswegen zwei Ziele verfolgt: Der freie Verkehr von gentechnisch veränderten Lebensmitteln und die Berücksichtigung des Vorsorgeprinzips. Die Rechtsprechung des Europäischen Gerichtshofs hat sich in die Richtung entwickelt, dass die Ausnahmen von dem freien Warenverkehr sehr eng interpretiert werden und dass die Mitgliedstaaten in der Praxis nicht viele Möglichkeiten haben, diese Ausnahmen durchzusetzen.

The recycling of waste metallic materials and the use of scrap are important for the economic production of a steelworks. Here, we investigate the technology of remelting steel chips. It was confirmed that the main problems with using chips in an electric arc furnace were the chips' large specific surface and the high losses due to the chipsć oxidation. To overcome both problems the compaction and remelting of the chips were tested. The investigation revealed that a major problem for the recycling ecology of steel chips was the safe removal of cutting fluids and oils from the chips' surface. The chemical analysis of the remelted chips confirmed that stainless-steel chips can be an acceptable source of the alloying elements chromium, nickel and molybdenum. Recikliranje odpadnih kovinskih materialov in uporaba starega železa sta pomembna za ekonomiko železarne. Tehnologija proizvodnje jekla s pretaljevanjem starega železa v elektro obločni peči je primerna tudi za jeklene ostružke. Preizkušena je bila tehnologija pretaljevanja jeklenih ostružkov. Glavni ugotovljeni problemi pri uporabi ostružkov v elektro obločni peči so velika specifična površina in velike talilne izgube zaradi oksidacije ostružkov. Zato je bilo preizkušeno stiskanje ostružkov in njihovo pretaljevanje. Predstavljeni so rezultati teh preizkusov. Ti so pokazali, da je bila glavna težava pri ekološkem recikliranju jeklenih ostružkov odstranitev rezilne tekočine in olj z njihove površine brez kontaminacije zraka. Kemijska analiza pretaljenih ostružkov je potrdila, da so ostružki nerjavnega jekla koristen vir legirnih elementov, kot so krom, nikelj in molibden.

An examination of the process of selective oxidation for molten pig iron indicates the possibility of lowering the content of unwanted or harmful elements. This process makes it possible to achieve the optimum Mn content in pig iron (hot metal) without any oxidation of the other elements present, suchas carbon, etc. Several variants of oxygen blowing with the addition of a slag-forming component were checked. The final element content in the hot metal depends on the initial Mn content, the oxygen blowing and on the added slag components. The lowering of the Mn content in the hot metal to the limit solves the problems of converter processing, lowers the slag quantity, increases the yield of steel by more 4 % and improves the steel-making process. Analiza procesa selektivne oksidacije tekočega grodlja daje možnost, da odstranimo neželene in škodljive elemente. Proces omogoča, da dosežemo optimalno vsebnost mangana v surovem grodlju (vroča kovina) brez oksidacije drugih elementov, ogljika in drugih. Preizkušenih je bilo več variant vpihovanja kisika z dodatki za tvorbo žlindre. Končna vsebnost mangana v grodlju je odvisna od začetne vsebnosti, vpihovanja kisika in od dodatkov za žlindranje. Zmanjšanje vsebnosti mangana do meje rešuje probleme konvertorskega procesiranja, zmanjša količino žlindre, poveča izkoristek jekla za več od 4 % in izboljša proces izdelave jekla.

U radu su prikazani rezultati mikrostrukturne analize troske nehrđajućeg čelika. Detaljno su analizirane troske nakon procesa oksidacije i redukcije u elektrolučnoj peći (ELP) te nakon oksidacije i redukcije taline VOD postupkom. ELP-VOD tehnološkim postupkom proizvodnje nehrđajućih tj. korozijski postojanih čelika nastaje troska bogata s kromovim oksidom. Nakon faze oksidacije u ELP sadržaj kromovog oksida iznosi oko 40%. Tako visok sadržaj kromovog oksida dovodi do slabe tečljivosti troske. Kromov oksid u trosci je vezan s oksidima željeza (FeO) i mangana (MnO) koji nastaju tijekom procesa oksidacije. Također, tijekom procesa oksidacije navedeni oksidi zajedno s magnezijevim oksidom stvaraju kompleksni spoj (FeOxMnOxMgO)xCr2O3. Krom se iz troske može ponovno vratiti u metalnu talinu dodatkom reducensa (FeSi ili Al).

The report presents data on HIV infection among men who have sex with men (MSM) in Slovenia during 1999-2008. HIV surveillance was based on universal mandatory reporting of HIV/AIDS cases, monitoring HIV infection prevalence among sentinel populations of MSM and STI patients and selected behaviour indicators in a sentinel population of MSM. Among 48 newly diagnosed HIV cases reported for 2008, 34 were MSM. Since 1999, the annual reported rate of HIV diagnoses in MSM rose from 7.1 to 46.8 per million men aged 15-64 years (an increase of more than six times). During 1999-2008, the proportion of MSM diagnosed with AIDS within three months of HIV diagnosis declined from 60% to 21%, however, the corresponding rate per million men aged 15-64 increased from 4.3 to 9.6. During 1999-2008, HIV prevalence among male clients of STI outpatient services tested for syphilis (including a substantial proportion of MSM) increased from 0% to 3.4%, and it remained below 5% in a sentinel population of MSM in Ljubljana. In the same sentinel population of MSM, the proportion reporting HIV test last year increased from 29% in 2003 to 38% in 2008 while the proportion reporting condom use at last anal intercourse decreased from 81% in 2004 to 66% in 2008. The burden of HIV among MSM in Slovenia is disproportionately high and increasing fast. Promotion of safer sexual behaviour and HIV testing among MSM as well as positive prevention among MSM with diagnosed HIV infection are urgently needed.

Diplomska naloga predstavlja razlikovalno rabo samostalnika v osrednje- in vzhodnoslovenskem knjižnem jeziku. Predstavitev rabe temelji na analizi dveh prevodov Matejevega evangelija, in sicer Trubarjevega in Küzmičevega. V uvodu sta na kratko predstavljena oba slovenska protestantska pisca, Primož Trubar in Å tevan Küzmič, značilnosti njunega jezika, pisavi, ki sta jo uporabljala, pobude za nastanek Matejevega evangelija in krajÅ¡a predstavitev le-tega. Samostalniki, ki so izpisani iz Matejevega evangelija, so analizirani na oblikoslovni in glasoslovni ravni. Analiza temelji na primerjalnem izpisu strocerkvenoslovanskih samostalnikov s Trubarjevimi (1555) in Küzmičevimi (1771) oblikami ter danaÅ¡njo knjižno normo (SSKJ). Gradivo je urejeno po sistemu starocerkvenoslovanskih sklanjatev. V nalogo ni vključenega raziskovanja dvojine, saj je analiza besedila pokazala, da je primerov, kjer je samostalnik zapisan v dvojini zelo malo. Nalogi je na koncu dodan Å¡e slovarček, v katerem so zbrani samostalniki, ki so bili uporabljeni pri analizi. Slovarček kaže razlikovalno Trubarjevo in Küzmičevo rabo samostalnikov, njihove slovnične lastnosti, sklanjatev, pomen in primerjalni zapis v stari cerkveni slovanščini ter sodobnem slovenskem knjižnem jeziku. Delo je zaokroženo z zaključkom, ki podaja sklepne ugotovitve. This diploma paper presents differential usage of the noun in the central- and east-Slovenian literary language. The presentation of the usage is based on an analysis of two translations of the Gospel of Matthew, namely those of Primož Trubar and Števan Küzmič. The introduction briefly presents both Slovenian Protestant authors, i.e. Primož Trubar and Števan Küzmič, the characteristics of their language, the writing system used, the incentives for the creation of the Gospel of Matthew and a short presentation of the Gospel. Nouns, which are taken from the Gospel of Matthew, are analysed on the level of morphology and phonetics. The analysis is based on a comparative extract of the Old Church Slavonic nouns with Trubar’s (1555) and Küzmič’s (1771) forms as well as today’s literary norm (Dictionary of Slovene Literary Language). The material is sorted by the system of Old Church Slavonic declinations. The paper, however, does not include the research of the dual, as the analysis of the text showed that there are very few cases of nouns written in the dual form. At the end of the paper, there is a glossary of nouns which were used in the analysis. The glossary shows the different usage of nouns by Trubar and Küzmič, their grammatical characteristics, declinations, meanings, and a comparative written record in the Old Church Slavonic and modern Slovenian literary language. The work is round up with the conclusion, which contains the final conclusions.

During a test in a wet salt (NaCl) chamber rusty spots and elongated pits appeared on the brushed surface of a prototype casing for a household device made from AISI 304 stainless steel. The corrosion pits only formed on the brushed surface and on the deformed edges. Metallography revealed deformation-induced martensite and delta ferrite in the microstructure. In the wet salt environment the brushed surface showed a lower corrosion resistance than the non-brushed surface. The corrosion was explained as being due to damage to the protective oxide layer with brushing, insufficient re-passivation and the presence of iton particles. The corrosion propensity of the brushed surface of the casing was increased by the presence of deformation-induced martensite, delta ferrite and, probably, the remains of iron particles. The use of AISI 316 stainless steel, alloyed with molybdenum, would be more appropriate for avoiding the formation of corrosion pits due to chloride ions in a wet environment. Ohišje prototipne gospodinjske naprave je bilo izdelano iz nerjavnega jekla AISI 304. Iz dekorativnih razlogov je bila površina krtačena. Med preskusom v vlažni slani komori se je pojavila korozija v obliki rjastih madežev in podolgovatih jamic vzdolž zakrivljenega roba. Predstavljeni so rezultati metalografske preiskave in analiza korozijskih produktov. Korozijske jamice se opazi samo na predhodno krtačeni površini in po deformiranih robovih. Z metalografskimi preiskavami smo odkrili v mikrostrukturi po deformiranih robovih prisotnost deformacijskega martenzita in delta ferita. V vlažnem slanem (NaCl) okolju je krtačena površina pokazala slabšo korozijsko odpornost v primerjavi z neobdelano površino. Glavna razloga za korozijo sta med krtačenjem poškodovan oksidni sloj in slaba repasivacija po krtačenju. Dodatno so lahko k pojavu korozije prispevali še deformacijski martenzit, delta ferit in ostanki delcev železa na površini. Posledica slabše korozijske odpornosti je pojav jamičaste korozije v vlažnem, slanem okolju. Za zmanjšanje možnosti pojava jamičaste korozije bi bila bolj primerna izbira nerjavnega jekla AISI 316, ki je legirano z molibdenom in s tem bolj odporno proti pojavu jamičaste korozije.

Protective oxide and/or nitride layers on AISI 321 stainless steel were prepared by thermal treatment in air and two controlled atmospheres in a laboratory simulation of an actual technological procedure. Samples’ surface was imaged by Scanning Electron Microscopy (SEM), elemental composition of the substrates was checked by Wavelength Dispersive Spectroscopy (WDS) and depth profiles of the samples were measured by Auger Electron Spectroscopy (AES). Since protective layer thicknesses were found to be of the order of hundreds of nanometers an attempt was made to obtain some fast averaged information about layers composition by Wavelength Dispersive Spectroscopy (WDS) with appropriately adjusted primary beam energy. Electrochemical corrosion testing was also performed on samples., Zaštitne oksidne i/ili nitridne slojeve na AISI 321 nerđajućem čeliku pripremljen toplinskom obradom materijala na zraku i u 2 kontrolirana tipa atmosfera kao laboratorijsku simulaciju stvarnog tehnološkog procesa. Slike površine uzoraka dobijene tehnikom SEM, sastav substrata metodom WDS a za profilnu analizu upotrijebljena je spektroskopija Augerovih elektrona (AES). Kako je ustanovljeno da su debljine formiranih zaštitnih slojeva reda veličine nekoliko stotina nanometara pokušalo se doći do ocjene o prosječnom sastavu unutar sloja upotrijebom tehnike WDS uz odgovarajuće odabranu energiju primarnog elektronskog snopa. Na uzorcima je provjereno i korozijsko testiranje.

U radu su prikazani rezultati mikrostrukturne (SEM) i fazne (XRD) analize skrutnute troske dobivene pri proizvodnji visokolegiranih nehrđajućih čelika vakuumskim (VOD) postupkom. Detaljno je analizirana troska nastala nakon oksidacije ugljika. Tijekom perioda oksidacije ugljika dolazi do nastanka kromovog oksida Cr2O3 koji vezan s oksidom željeza stvara kromit FeO×Cr2O3. Provedenom analizom je uz FeO×Cr2O3 u trosci utvrđena prisutnost MnO×Cr2O3, MgO×Cr2O3 i kompleksnog spinela (FeO×MnO×MgO)×Cr2O3. Prosječni sadržaj Cr2O3 u trosci iznosi 25-40 %, dok u kromitu može biti Cr2O3 iznad 70 %. Zbog nastalih kromita takve troske su slabo tečljive, tj. tjestaste (kašaste). Krom se iz troske može ponovno vratiti u metalnu talinu dodatkom reducensa, najčešće ferosilicija ili aluminija.

SEM analiza provedena je na troskama dobivenim pri proizvodnji čelika legiranih s kromom (nehrđajući čelik). Za vrijeme snižavanja sadržaja ugljika (period oksidacije) nastaju kromiti koji imaju vrlo visoko talište. Budući je temperatura taline oko 1700°C uslijed visokog tališta kromita troska postaje tjestasta odnosno kašasta. SEM analiza ukazuje da je kromov oksid vjerojatno vezan s oksidom željeza i stvara kromit FeOxCr2O3. Međutim, istovremeno dolazi do oksidacije i dijela mangana koji uz prisutan magnezijev oksid stvara spojeve tipa (FeOxMnOxMgO)xCr2O3.

Izvor kontroverzi o Althusiusovoj Politici, koje traju već četristo godina, nije sámo djelo, nego prije svega, njegovo tumačenje. Autor drži da pritom nije sporno da Althusiusovo političko učenje i njegova sistematičnost pružaju iznimnu osnovu za teorijsku raspravu o našoj političkoteorijskoj i općenito kulturnoj misaonoj tradiciji. U prvom dijelu članka autor prikazuje temeljne pojmove Althusiusova političkog mišljenja, te logiku njihova izlaganja u Politici. Pokazuje se da je riječ o sustavnom, tj. metodički izloženom istraživanju politike, kao načinu na koji se ljudi udružuju u svrhu ostvarenja dobrog života putem communicatio stvari, poslova i prava. Shodno tomu, politička se znanost bavi stvarnim ili idealnim načinima tog udruživanja i rezultatima tog udruživanja. Althusius je bio prvi autor koji je eksplicitno izrekao kako samo narod kao cjelina može biti suveren te je stvorio teorijski koncept narodne suverenosti. Taj dio njegovog učenja predstavlja najveći i istodobno jedini uglavnom nekontroverzan Althusiusov doprinos političkoj misli. U drugom dijelu analitički se raspravlja i pomno vrednuje diskusija o razumijevanju “kontroverznih” osnovnih elemenata Althusiusova nauka, koji se odnose na bit ljudske zajednice i karakter njezinog političkog organiziranja. Autor zaključno obrazlaže kako Althusiusovo djelo predstavlja svojevrsno sjecište tada “poraženih”, a danas sve aktualnijih ideja: to su komunitarizam (nasuprot individualizmu) i društvena solidarnost (naspram jednostrane maksimalizacije pojedinčeve koristi), svojevrsna matrična struktura društvenog sustava (nasuprot političko-piramidalnoj), tj. autonomija njezinih dijelova (naspram monolitnosti centralističkodržavnog sustava). U osvit novog doba, elemente tih tradicija koje će uskoro biti (privremeno) poražene, Althusius je sistematski izložio u svom epohalnom djelu, čiji se unutarnji potencijal sve jasnije razaznaje kao jedno od mjerodavnih izvorišta modernoga političkog mišljenja., The source of the four centuries of controversies surrounding Althusius’ Politics is not the work itself but its interpretations. The author argues that Althusius’ political teaching is not controversial; also, its methodicalness is highly conducive to a theoretical debate about the political/theoretical and cultural tradition of thought in general. In the first part, the author identifies the fundamental concepts of Althusius’ political thought, and the logic of his exposition in Politics. He shows that Althusius’ is a systematic – methodicaly presented – study of politics; politics is a way in which people unite in order to have a good life by means of the communicatio of things, services and right. Consequently, political science deals with the real or ideal ways of this association and its results. Althusius was the first author who explicitly said that only a people as a whole may be sovereign. He also created a theoretical concept of popular sovereignty. That part of his teaching is the greatest and largely undisputed Althusius’ contribution to political thought. In the second part, the debate about the interpretation of the “controversial” fundamental tenets of Althusius’ teaching is reviewed, the tenets that refer to the essence of human community and the character of its political organization. The author concludes that Althusius’ work is a sort of a junction of the then “defeated” but today increasingly popular ideas: communitarianism (versus individualism) and social solidarity (versus the onesided maximalization of individual benefit), a kind of a matrixal structure of social system (versus political-pyramidal), i.e. the autonomy of its parts (versus the monolith centralist-state system). In the dawn of a new era, the elements of those traditions that were soon to be (temporarily) defeated, were systematically depicted in Althusius’ epochal opus, whose internal potential is increasingly recognized as one of the most relevant provenances of modern political thought.

Mechanism of the oxidation of the thermal-resistant Fe-C-Si-Al-Zr alloys was investigated at high temperatures. For the analysis three series samples: L1, L2 and L3, had been annealed at 1100 °C, were cast. After annealing the samples were investigated on the oxide thickness increase. They were observed and analysed by optical and electron microscopes. In case of the small zirconium content in the L1 sample, the graphite lamellae and only a significant amount of zirconium carbide in the ferrite matrix have been observed. At higher zirconium content (the L2 and L3 samples) graphite lamellae and particles of ZrC have been observed. During annealing an oxidation of graphite and ZrC took place. The oxidation of ZrC into ZrO2 is direct and progressive. Evolving CO gas formed the pores around ZrO2. Under sufficient amount of the dissolved oxygen the oxidation of aluminium was taking place too. Al2O3 was precipitating in the CO-ferrite interface filling up the formed pores. Finally the interaction between ZrO2 and Al2O3 were taking place and formation the compound of ZrO2·Al2O3 retarded further oxidation., Ispitivao se mehanizam oksidacije termički otpornih legura Fe-C-Si-Al-Zr na visokim temperaturama. Za analizu su izlivena tri serijska uzorka L1, L2 i L3, i žarena na 1100 °C. Nakon žarenja uzoraka ispitivana je debljina oksidnog sloja. Promatrani su i analizirani optičkim i elektronskim mikroskopom. Kad je količina cirkonija bila mala u uzorku L1 uočene su grafitne lamele i čestice ZrC. Tijekom žarenja došlo je do oksidacije grafita i ZrC. Oksidacija ZrC u ZrO2 je vanjska i progresivna. Razvija se plin CO, koji oko ZrO2 formira pore. Kad je količina rastopljenog kisika postala dovoljno velika došlo je također do oksidacije aluminija. Al2O3 se istaložio u CO-feritnom međuprostoru i popunio postojeće pore. Konačno je došlo do interakcije između ZrO2 i Al2O3 te se stvorio spoj ZrO2·Al2O3 koji je usporio daljnju oksidaciju.

The use of electromagnetic stirring (EMS) for continuous casting brings metallurgical benefits to cast billets. At the Inexa Steelwork Štore we examined the influence of electromagnetic stirring on the solidification structure of cast steel billets with a size of 180 x 180 mm. EMS was applied to improve the surface and subsurface quality as well as the internal quality of continuously cast steel by enlarging the equiaxed zone of the cast billets or blooms. In this paper a comparison of the macrostructures of stirred and non- stirred billets is presented. Uporaba elektromagnetnega mešanja (EMM) pri kontinuirnem litju prispeva k boljši kvaliteti gredic. Vpliv EMS na strukturo strjevanja smo preiskovali prilitju gredic 180 mm x 180 mm na napravi za kontinuirno litje jekla v železarni Inexa Štore. Z uporabo EMM se doseže izboljšanje kvalitete na površini, pod površino in notranji strukturi ulitega jekla s povečanjem sredinskega globulitnega področja ulitih gredic ali blumov. V prispevku je predstavljen vpliv elektromagnetnega mešanja na makrostrukturo in mikrostrukturo ulitih gredic.

An investigation conducted on two steel ploughs found at Saint Ahac above Ilirska Bistrica dating from the fourth and the sixth centuries AD are presented. The ploughs were made by forge-welding many layers of steel extracted directly from the furnace melt containing mainly slag inclusions. The ploughs were made by placing steels of higher strength and hardness where the load was greatest. Metallographic examination, chemical and microchemical analysis and hardness measurements contributed significantly to the information regarding the manufacturing process of the archeological ploughs. Possible reactions during melting and steel production are also presented. Predstavljena je raziskava dveh jeklenih ral iz najdišča Sveti Ahac nad Ilirsko Bistrico, ki izvirata iz četrtega do šestega stoletja našega štetja. Izdelana sta bila s kovaškim privarjanjem več plasti jekla, ki je bilo pridobljeno z neposrednim taljenjem v peči in je vsebovalo veliko vključkov žlindre. Ralo je bilo narejeno tako, da je bilo jeklo večje trdnosti in trdote uporabljeno na bolj obremenjenem delu. Z metalografskimi preiskavami, kemično in mikrokemično analizo ter meritvami trdot smo pridobili veliko število informacij, na osnovi katerih podajamo sliko o izdelavi zgodovinskega rala. Prikazane so tudi možne reakcije v peči pri taljenju in nastajanju jekla.

Al/SiC kompoziti predstavljajo sodobne materiale, katerih bodočnost je nesporna, zaradi mnogih dobrih lastnosti, ki so primerljive tudi z nekaterimi Ti zlitinami. Trenutno je njihova uporaba še vedno omejena na letalsko industrijo in vojaške tehnologije. Pričakuje pa se, da bo v nekaj letih razvoj in komercializacija teh materialov napredovala do te mere, da bodo pričeli ti materiali prodirati tudi na druga področja. Tu imamo v mislih vse vrste transportnih vozil in predvsem avtomobilsko industrijo. Izdelava Al/SiC kompozitov je možna na več načinov: z umešavanjem relativno grobih delcev ojačitvene faze (siC) v raztegnjeno osnovo (talino Al zlitine), z infiltracijo keramičnih preoblikovancev in postopki metalurgije prahov. V okviru temeljnega projekta, ki ga financira MZT RS, smo v preteklem letu pričeli spoznavati to vrsto materialov in osvajati postopke njihove izdelave. Izdelali smo reaktor za umešavanje delcev v talino in pričeli praktične preizkuse izdelave kompozitov. Za primerjavo tega postopka in dosegljivih lastnosti smo izdelali tudi kompozite s postopkom metalurgije prahov. Predstavljeno je opravljeno razvojno raziskovalno delo s poudarkom na doseženih rezultatih in opisu težav, na katere smo naleteli pri reševanju povečanja omočljivosti ojačitvene faze, diseganju njene enakomerne porazdelitve v kovinski osnovi ter zmanjšanju neželjenih reakcij med delci in matriksom.

Highlights of the technological scheme of manufacturing quality steels as stainless steels in the vacuum by the duplex EAF (electrical arc furnace) + VOD (vacuum oxygen decarburization) process is presented here. Special attention is given to the stage of vacuum. In short feature the VOD computer program is expalained, which enables the effective preparation of the complete technology for VOD - process from 15 to 100 tonnes. Predstavitev tehnološke sheme izdelave kvalitetnih jekel v vakuumu kot so nerjavna jekla po duplex postopku EOP (elektro-obločna peč) + VOD (vakuumsko kisikovo žilavenje). Poseben poudarek je podan na procesno stopnjo vakuumske oksidacije ogljika in kroma ter izkušnje pri uporabi vakuuma. Na kratko bo predstavljen tudi računalniški program oziroma rezultati modeliranja, ki omogočajo hitro in učinkovito pripravo kompletne tehnologije VOD procesa za peči kapacitete 15 do 100 ton.

Most of steel is made from pig iron which has high carbon content. The intention of the project was to find how model investigations can help in studying the decarbuzation processes. In the reactor model the decarbuzation reaction was simulated by using 0.1 M KOH solution and blowing of CO sup 2 and N sup 2. Such model investigation enable the understanding of the effects of the gas being blown on and through the melt, on the formation of interfase surfaces. The investigations consisted of two stages. In the first stage, gas mixture was introduced through three tuyeres, being placed in the reactor bottom in a row which did not coincide with the central line. The influence of the number of tuyeres and their arraying, and on the height/diameter ratio of the bath on the flow patternes was studied. In the second stage, the decarburization process with the lance mouth from the melt surface, a constant amount of CO sup 2 + N sup 2 gas mixure was introducted, while N sup 2 for melt stirring was blown through eight nozzles in three different concentric circles on the reactor bottom. Measurement of electrical conductivity enabled the determination of variations of initial concentrations. The described results show the possibility for model investigations of the processes, enabling its optimization towards a reduced duration of the process and an increased throughput of the reactor. Na modelih smo prikazali študij procesa razogljičenja čistih Fe-C talin z vpihavanjem kisika na površino taline in brez sodelovanja žlindrine faze. Razisakve se nanašajo na diskontiunirano delovanje reaktorja. Na modelu reaktorja smo z uporabo Co spodaj 2 in KOH raziskovali vpliv dovoda plina natalino s kopjem in skozi dno na hitrost reakcije. Premešavanje kopeli naj bo takšno, da bo ta homogena. Na hitrost kemijske reakcije pri treh ekscentrično postavljenih dovodih plinske mešanice CO spodaj 2 + N spodaj 2 in pri razmerju H:D=0.5 vpliva povečan pretok plinske mešanice linearno. Pri tem razmerju je tudi homogenejša. Na hitrost rrakcije in homogenost ima največji vpliv kombinirano premešavanje. Z vrha smo dovajali CO spodaj 2 + N spodaj 2, z dna pa premešavali z dušikom. V delu so podani grafični prikazi spremembe hitrosti reakcije pri različnih načinih dodajanja reagenta v kopel.