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1

Warunki zatarcia dla pary ciernej stal-tlenek chromu (Cr2O3)

Rusowicz Artur

Szkło i Ceramika

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2022

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R. 73, nr 1

49--53

PL

W poprzednim artykule zostały przedstawione wyniki badań dla próbek stali pokrytej warstwą węgliku wolframu (WC), dla której okazało się, że proces zatarcia przebiega podobnie jak dla par roboczych stal-stal. W niniejszym artykule przedstawione są wyniki badań dla próbek pokrytych tlenkiem chromu, dla którego pierwsze objawy zatarcia pojawiły się dla obciążeń normalnych o wartościach Pn = 0,5-1,5 kN. Po czym następowało wahanie wartości sił stycznych i wzrost temperatury próbek. Przy wartościach siły normalnej na poziomie Pn = (1,2-2,0) kN następował gwałtowny wzrost sił stycznych i dalszy wzrost temperatury próbek. Maksymalna temperatura próbek wynosiła od 82,7°C do 111°C. Powierzchnie próbek nie wykazywały istotnego zużycia ciernego.

2

Rynek surowców żelaza i stali w początkach XXI wieku

Paulo Andrzej, Krzak Mariusz

Przegląd Geologiczny

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2022

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Vol. 70, nr 3

156--171

EN

Iron and steel raw materials market evolves rapidly. Global mine production of iron ores and concentrates, metallurgical coal, pig iron and crude steel exceeded 1 billion tonnes at the turn of the 20th and 21st centuries or in the first 20years of new millennium. International trade in these fields, as well as trade of such products as coke, ferroalloys and scrap, is also huge. Demand growth rate for steel raw materials, finished and semi-finished steel, and cast iron products is currently the highest among other mineral raw materials. Almost 90% of iron ore supplies come from Australia and Brazil, and the dominant consumer - China - is responsible for almost use. A geographic evolution in the steel production and the consumption of derived products has taken place. China has grown from a secondary crude steel producer and secondary steel products user to a leader with over 50% global share of steel production and a leading exporter of finished products. The iron and steel market has concentrated in the East and South Asia due to high consumption of imported steel raw materials in Japan and South Korea, rapid demand growth in India, investment in energy-efficient scrap processing in Turkey and Iran, while simultaneous reductions in the production capacity of the steel industry in the European Union, former Soviet Union and the US. Market disruption due to Covid-19pandemic appears to be short-lived, and China has strengthened its position. In the first half of 2021, the prices of steel products increased dramatically, which immediately resulted in the change in prices of apartments and other constructions based on this most widely used metal.

3

Materiały budowlane stosowane do realizacji gazociągów przesyłowych i dystrybucyjnych

Myrczek Józef, Kosmalski Sebastian

Materiały Budowlane

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2022

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nr 10

86--89

PL

Polskie przepisy dopuszczają stosowanie do budowy gazociągów wyroby stalowe i polietylenowe. Parametry wytrzymałościowe stali przewyższają odpowiednie wartości parametrów polietylenu. Gazociągi wysokiego ciśnienia wykonywane są wyłącznie ze stali. Gazociągi niskiego i średniego ciśnienia o maksymalnym ciśnieniu roboczym do 1 MPa mogą być wykonane z polietylenu. Obiekty towarzyszące wykonuje się tylko w technologii stalowej. Wybór odpowiedniego materiału uwzględnia również wiele innych parametrów, takich jak odporność na korozję, łatwość i koszt montażu, proces spajania, odporność na wzrost naprężeń, niezawodność. W artykule opisano cechy obu materiałów w kontekście uwarunkowań formalnych i technicznych.

EN

According to polish regulations two materials can be used in gas pipeline construction, namely steel and polyethylene. The strength parameters of the steel exceed the corresponding values of polyethylene. High pressure gas pipelines are made only of steel. Low pressure and medium pressure gas pipelines with a maximum working pressure up to 1 MPa may be made of polyethylene. The accompanying facilities are made only in steel technology. The selection of the appropriate material takes into account also a number of other parameters, such as corrosion resistance, ease and cost of assembly, the bonding and welding process, resistance to crack, and reliability. The article describes the main features of the materials in relation to formal and technical requirements.

4

Kryteria doboru materiałów do wytwarzania gazociągów przesyłowych i dystrybucyjnych

Kosmalski Sebastian, Myrczek Józef

Materiały Budowlane

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2022

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nr 11

13--15

PL

W konstrukcji gazociągów można stosować stal lub polietylen. W artykule przeanalizowano czynniki wpływające na wybór preferowanego materiału konstrukcyjnego. Uwzględniono: wymagania formalne, normatywne, techniczne, ekonomiczne, środowiskowe, bezpieczeństwa, czasu realizacji, warunki operatora/zleceniodawcy oraz występujące ryzyko. Gdy możliwe jest zamienne stosowanie polietylenu i stali, preferowane jest użycie polietylenu. W przypadku wysokiego ciśnienia w gazociągu jedynym dopuszczalnym materiałem jest stal.

EN

Both steel and polyethylene can be used in the construction of gas pipelines. The articles concerns the factors determining the choice of preferred construction material. The following factors were taken into account: formal and normative requirements, technical, economic, environmental, safety, implementation time, operator’s / investor’s requirements and the risk involved. Where polyethylene and steel can be used interchangeably, polyethylene should be preferred. Steel is the only acceptable material for high pressures pipelines.

5

The Heat Transfer Process Between Two Bodies with a Large Temperature Difference

Przyłucka-Bednarska Aleksandra, Rywotycki Marcin, Sołek Krzysztof, Malinowski Zbigniew

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 3

1161--1165

EN

Heat transport when two surfaces of solids come into contact is an important phenomenon in many metallurgical processes. Determining the boundary conditions of heat transfer allows to obtain the correct solutions of the heat conduction equation. The paper presents models for determining the heat transfer coefficient between steel materials in contact. Experimental tests were carried out to measure the temperature changes of the contacting samples made of steel S235 (1.0038) and steel 15HM (1.7335) under the pressure of 10, 15 and 20 MPa. There was a large temperature difference between the samples. The results of the experiment were compared with numerically calculated temperatures and the value of the heat transfer coefficient was determined at different pressure values depending on the time.

6

The Adjustment of the Tundish Water Model of Continuous Casting

Blaško Peter, Bulko Branislav, Petrík Jozef, Demeter Peter, Socha Vladimir, Hanáková Lenka, Palfy Pavol, Solc Marek, Vasilňáková Andrea

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 1

97--104

EN

Whereas approximately 96.3% of the steel produced worldwide is made by continuous casting, great emphasis is put on the superior efficiency of this process. The water model of the tundish and mathematical modeling is often used for the simulation of the steel flow during continuous casting. The experiments were performed on a model of the tundish with two outlets, at two casting speeds (0.8 m.s-1 and 1.2 m.s-1). Eight setups of the tundish were evaluated, which differed in the design of the dams (with or without drainage holes), in their distance from the center of the tundish, and their height. The contribution of the work is the analysis of phenomena in the tundish water model in conditions of repeatability (ten repetitions). The goal is to find the setup providing the most symmetrical flow, with the minimum difference in the residence times Δτ on the two outlets. Taking into account the results obtained at both casting speeds, the most preferred is setup 2 with the 87 mm high dams placed 587 mm from the center of tundish (Δτ = 0.5). The setup 3 (Δτ = 8.25) appears to be the least appropriate. The higher the casting speed, the higher the number of unsuitable arrangements.

7

A comparison of elasto-plastic parameters of S355 steel obtained in tensile tests using an extensometer, a strain gauge and an ARAMIS 3D DIC system

Chybiński Marcin, Dębiński Janusz, Glema Adam, Grzymisławska Justyna, Jezierski Dariusz, Polus Łukasz, Szymkuć Wojciech

Archives of Civil Engineering

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2022

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Vol. 68, nr 4

199--217

EN

The paper presents a comparison of three strain measurement methods. The mechanical parameters of S355 grade steel (yield strength, tensile strength, modulus of elasticity) were determined in tensile tests. Strains were measured using high resolution measuring instruments: an extensometer, a strain gauge and an ARAMIS 3D DIC system. In this paper, these three instruments have been used simultaneously in tensile tests for the first time. The results indicate that the values of the Young’s modulus obtained using different techniques were similar when each instrument measured strain on the same side of the sample. Small differences were connected with different gauge lengths and their locations. The values of the Young’s modulus determined on the opposite sides of the samples were more varied even when the same method was used (strain gauge measurements). For this reason, it is recommended to use double-sided averaging instruments when the Young’s modulus is determined. The strain-curves obtained from the strain gauge measurements were incomplete and they came to an end at the end of the yield plateau due to the fact that they were damaged when the values of strain were relatively high. The extensometer was used up to the point where the strain reached 0.3% and then the strain was measured based on the distance between the machine clamps. The stress-strain curves obtained from the DIC system were complete because the system was able to monitor the sample until the very end of the tests.

PL

W artykule przedstawiono porównanie trzech metod pomiarowych odkształceń. Autorzy wyznaczyli parametry mechaniczne stali S355 (granicę plastyczności, wytrzymałość na rozciąganie, moduł elastyczności) w próbie rozciągania. Odkształcenie zostało wyznaczone przy użyciu przyrządów pomiarowych o wysokiej rozdzielczości: ekstensometru, tensometru oraz systemu cyfrowej korelacji obrazu ARAMIS 3D. Po raz pierwszy w próbie rozciągania wykorzystano wszystkie urządzenia pomiarowe jednocześnie. Wartości modułu Younga wyznaczone za pomocą różnych metod były zbliżone, gdy urządzenie mierzyły odkształcenie po tej samej stronie próbki. Niewielkie różnice wynikały z różnych długości pomiarowych oraz z faktu, że przyrządy nie mierzyły odkształcenia dokładnie na tej samej bazie pomiarowej. Wartości moduły Younga wyznaczone dla przeciwnych stron próbki różniły się bardziej nawet, gdy zastosowano tą samą metodę pomiarową (pomiar odkształceń za pomocą tensometrów). W związku z tym w celu wyznaczenia prawidłowej wartości modułu elastyczności zaleca się stosowanie dwóch urządzeń rozmieszonych na przeciwnych stronach próbki oraz obliczanie modułu sprężystości na podstawie średniej wartości odkształcenia. Krzywe naprężenie-odkształcenie otrzymane z pomiarów tensometrycznych były niekompletne i kończyły się zaraz po półce plastycznej, ponieważ tensometry ulegały uszkodzeniu przy większych wartościach odkształceń. Ekstensometr był wykorzystywany do momentu, w którym odkształcenia osiągnęły wartość 0,3%. Od tej wartości odkształcenia były wyznaczane na podstawie odległości między szczękami maszyny. Krzywe naprężenie-odkształcenie otrzymane na podstawie cyfrowej korelacji obrazu były kompletne, ponieważ system mógł obserwować próbkę przez całe badanie. Z tego względu, metoda cyfrowej korelacji obrazu jest skutecznym narzędziem, które może być wykorzystane do wyznaczania parametrów mechanicznych stali.

8

Studies on the Mechanical Properties of C45 Steel with Martensitic Structure after a High Tempering Process

Woźniak Waldemar, Sąsiadek Michał, Jachowicz Tomasz, Edl Milan, Zając Paweł

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 3

306--315

EN

This article describes the studies of the mechanical properties of the martensitic structure of C45 steel, obtained as a result of heat treatment. This steel was subjected to high tempering, within the temperature range of 500 ÷ 700°C (every 50°C) and for various exposure times, from 15 minutes to 23 hours. Moreover, martensitic steel was subjected to tests by quenching at a temperature of 850°C for 20 minutes and then tempering it for 1 hour, within the temperature range of 50 ÷ 800°C (every 50°C). The resulting steel samples were subjected to strength tests, that is, to tensile and hardness tests and also to tests on the micro-structure. The results of these studies are presented and discussed, in detail, in terms of their practical application.

9

Microstructure and Hardness of Cold Forged 42CrMo4 Steel Hollow Component with the Outer Flange

Szala Mirosław, Winiarski Grzegorz, Bulzak Tomasz, Wójcik Łukasz

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

201--210

EN

For decades, steel has been a crucial structural material. Mainly low-alloy steel grade ISO 42CrMo4 is utilized for manufacturing forgings. This paper investigates the microstructure and hardness development of the 42CrMo4 steel hollow component with an outer flange. The component has been formed via cold forging in combination with extrusion and upsetting technologies. Prior to forming, the workpiece was annealed to obtain hardness at the level of 181±9 HV0.3. The FEM analysis reveals the areas that undergo higher stress and strain. The flow lines macrostructure and microstructure of hollow parts were investigated using light optical microscopy (LOM) and scanning electron microscopy (SEM) equipped with EDS. Vickers hardness allows identifying the work hardening of the crucial element areas. The microstructure consists of ferrite matrix and semi-globular carbides. Laboratory studies confirm appropriate flow lines arrangement, which corresponds well to those shown by FEM computer simulations. The highest hardness at the level of 293±7 HV0.3 was identified in the flange area, where the material shows a higher distribution of effective strain revealed by FEM. Cold metal forming results in work-hardening of the steel. The work hardening ranges up to 1.62 of the initial 42CrMo4 steel hardness. The metal forming process did not affect the microstructural uniformity of the flanged hollow part. The final outer flange component presents high quality and is free from plastic deformation nonuniformities.

10

Investigation on Corrosion Inhibition of Hura Crepitans for 2101 Duplex Stainless Steel in an Acidic Environment

Temitayo Ogunmodede O., Vawe Humwapwa, Johnson Jonathan, Adewole Ezekie, Ilesanmi Osasona

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 4

56--63

EN

Corrosion is a global menace which has imparted the world economy greatly. One of the solutions proffered to these challenges is the use of inhibitors. Several natural inhibitors have been used to protect engineering materials from corroding. This research is focused on investigating the inhibitive properties of Hura crepitans seed (HCS) on Duplex Stainless Steel 2101 (DSS2101) in H2SO4. The selected plant part was subjected to characterization to determine the presence of organic anti-corrosion agents present. From the result, phytochemicals such as saponin, tannins, steroid and flavonoids were observed. The presence of the organic group accounted for the inhibitive efficiency recorded in the environment. The polarization studies revealed that generally the inhibitor produced from seed extract of Hura crepitans, improved the corrosion resistance of DSS2101 in 0.5M H2SO4. The optimum corrosion inhibitor efficiency was observed at 0.2% inhibitors in 0.5M H2SO4 for 2101DSS.

11

Projektowanie ekologicznych konstrukcji stalowych

Miczko Marek, Zamorowski Jan

Przegląd Budowlany

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2021

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R. 92, nr 11-12

81--85

PL

W artykule przedstawiono problematykę dotyczącą ekologicznego projektowania konstrukcji stalowych. O tym, czy konstrukcja może zostać uznana za ekologiczną, decydują kryteria zrównoważonego rozwoju. Przedstawiono założenia filozofii zrównoważonego rozwoju oraz narzędzie normowe umożliwiające ocenę stopnia zrównoważoności obiektu budowlanego. Jest nim metoda „oceny cyklu życia” (z ang. LCA - Life Cycle Assessment), którą można stosować w ocenie całego obiektu, jak i pojedynczych materiałów lub technologii. Coraz bardziej popularne w Polsce stają się wielokryterialne systemy oceny środowiskowej budynków. Projektując stalowy obiekt, należy mieć na uwadze cały cykl jego istnienia.

EN

The article presents the issues related to ecological design of steel structures. The criteria of sustainable development determine whether a structure can be considered ecological. The assumptions of the philosophy of sustainable development and a standard tool enabling the assessment of the degree of sustainability of a building structure were presented. It is the „Life Cycle Assessment” (LCA) method, which can be used in the assessment of the entire facility as well as individual materials or technologies. Multi-criteria environmental assessment systems for buildings are becoming more and more popular in Poland. When designing a steel object, one should take into account its entire life cycle.

12

Investigation of corrosion rate of X55CrMo14 stainless steel at 65% nitrate acid at 348 K

Lipiński Tomasz

Production Engineering Archives

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2021

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Vol. 27, Iss. 2

108--111

EN

A number of factors determine the mechanical, but also physical and chemical properties. One of the most important are the steel microstructure and its working conditions. A few corrosion processes in crevices and awkward corners can be avoided at the design stage (low roughness parameters, roundsection and other). But still the construction material is exposed to corrosion. These steels often come into contact with an aggressive environment based on nitric acid. Stainless steel is more and more often used in many sectors of industry. The purpose of this article is to investigate corrosion resistance in different time (48, 96, 144, 192, 240, 288, 336, 384 and 432 hours) using weight loss and profile roughness parameters of martensitic steel in grade X55CrMo14 in nitric acid 65% pure-basic at temperature 348 K. Corrosion tests show that the tested steel in nitric acid as a corrosive environments is characterized through continuous corrosion process whose measure may be surface roughness.

13

Materials used in the structure of rail vehicle wheels

Słowiński Marcin Stanisław

Pojazdy Szynowe

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2021

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Nr 4

14--24

EN

The subject of this text is the description of structural materials used in the structure of railway vehicle wheels. The characteristic of this structural element as well as its functional and material requirements are presented. The description of commonly used carbon steels and alternative construction materials, such as cast steel, ADI cast iron or aluminum alloys, are presented in the further part, which are supposed to limit the wear of the wheel-rail friction pair and reduce the level of noise.

PL

Przedmiotem niniejszego tekstu jest opis materiałów konstrukcyjnych stosowanych w budowie kół pojazdów szynowych. Przedstawiono charakterystykę tego elementu konstrukcyjnego, a także jego wymagania funkcjonalne oraz materiałowe. W dalszej części zaprezentowano opis powszechnie używanych stali węglowych oraz alternatywnych materiałów konstrukcyjnych, takich jak staliwa, żeliwa ADI czy stopy aluminium, które w założeniu miałyby ograniczać zużywanie pary ciernej koło-szyna oraz zmniejszać poziom emitowanego hałasu.

14

Wpływ głównych parametrów wysokociśnieniowej strugi wodno-ściernej na jakość powierzchni przeciętej stali HARDOX 500

Perec Andrzej

Obróbka Metalu

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2021

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nr 2

34--39

PL

Przedstawiono wyniki badań wpływu najważniejszych parametrów procesu przecinania wysokociśnieniową strugą wodno-ścierną stali Hardox na chropowatość powstałej powierzchni. W celu określenia najkorzystniejszych parametrów kontrolnych procesu skrawania stworzono matematyczno-statystyczny model procesu cięcia wykorzystując metodę powierzchni odpowiedzi (RSM). Wybrano równanie wielomianowe drugiego stopnia i na jego podstawie stworzono model obróbki, umożliwiający znalezienie optymalnych parametrów kontrolnych oraz predykcję wartości chropowatości powierzchni przeciętej.

EN

The results of investigations of the influence of the most important parameters of the cutting process of highpressure water jet cutting of Hardox steel on the roughness of the resulting surface are presented. A mathematical-statistical model of the cutting process based on the response surface method (RSM) was created to determine the most favorable control parameters of the cutting process. A second-degree polynomial equation was chosen and a machining model was created based on this equation to find the optimal control parameters and predict the value of the cut surface roughness.

15

The Prospects of Abrasive Treatment of Tough-To-Machine Materials

Palacz Magdalena, Ivanova Tatiana N., Kozlov Alexander M., Kaniak Wojciech

Multidisciplinary Aspects of Production Engineering

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2021

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Vol. 4, Iss. 1

166--177

EN

In current conditions, great attention is paid to the quality of parts, which is in many ways determined by finishing operations of mechanical treatment, with surface grinding being the most widespread. Grinding process efficiency, abrasive tool wear intensity, machined surface quality and other features of grinding process depend on properties of the environment, where the cutting process takes place. Forced changing of conditions of this environment is one of the ways to control and optimize the grinding process, which can be reached due to finding new technological decisions. One of the most promising directions to solve this problem is the process of face grinding with discontinuous grinding tool and supply of cooling fluid or air in the cutting zone directly. Carried analysis of features of face grinding has shown that heat density can be decreased by the usage by grooved wheels with vortex air cooling or by supply of cooling-lubricant technological fluid. Obtained dependences of temperature field of part surface during grinding establish the influence of the length of working shoulders and grooves, vortex tubes number, outflow rate, temperature and flow rate of cold vortex flow of air. These data provide conscious control over the process of discontinuous face grinding by changing wheel grain size and grinding speed.

16

Analysis the Influence of Steel Sheet Production Technology on the Quality Products in Steel Service Polska

Sitko Jacek

Multidisciplinary Aspects of Production Engineering

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2021

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Vol. 4, Iss. 1

301--308

EN

The process of production and processing and preparation for distribution of steel products is associated with the requirements of maintaining appropriate procedures. They allow, in accordance with industry standards to avoid unforeseen problems associated with the preparation, implementation and finalization of activities aimed at achieving the intended purpose, which is a finished product of adequate quality and customer satisfaction. It is not always possible in the production process to meet all the requirements and technological, organizational and human factor recommendations. The analysis of selected problems, which includes the content of the article allows to significantly determine the factors and parameters associated with the preparation and technical implementation affecting the implementation of the intended objectives of the company, i.e. achieving an appropriate level of quality and minimizing the defects in the process of steel sheet preparation. Analysis of selected parameters was made on the basis of data obtained in the company operating on the international market Company Steel Service Poland. At the request of company representatives, the name has been changed due to the production data used in the article, which may be considered as sensitive. The article contains data based on research carried out in Steel Service Poland. Selected problems are the subject of analysis of steel sheets cutting processes with the analysis of causes of customer complaints with reference to the produced steel products. Selected steel grades and factors affecting the efficiency of the technological process are presented. The analysed set of factors translates into the level of product quality and reduction of arising defects.

17

Production Line Modelling in Accordance with the Industry 4.0 Concept as an Element of Process Management in the Iron and Steel Industry

Niekurzak Mariusz, Kubińska-Jabcoń Ewa

Management and Production Engineering Review

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2021

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Vol. 14, No. 4

3--12

EN

Simulations are becoming one of the most important techniques supporting production preparation, even in those industrial sectors with atypical technological processes, such as in metallurgy, where there is a multiphase material flow. This is due to the fact that in the conditions of a market economy, enterprises have to solve more and more complex problems in a shorter time. On the basis of the existing production process and the knowledge of the flow characteristics in a given process, a model is built, which, when subjected to simulation tests, provides experimental results in the scope of the defined problem. The use of computer techniques also creates new possibilities for the rational use of the reserves inherent in each technological process. Taking into account the existing demand and the state of modern technology, the computer model can be a source of information for further analysis and decision-making processes supporting company management. At work a model of the logistic system was made on the example of a hot-rolled steel strip mill, on which simulation experiments were carried out to improve the effectiveness and efficiency of the analysis production line. The presented article aims to disseminate the idea of ??Industry 4.0 in Polish companies from the manufacturing industry sector, taking into account simulation techniques.

18

Study on removal of copper, tin and arsenic from iron ore, scrap and steel in the light of the latest state of metallurgical technology

Zdonek Bogdan, Różański Piotr, Borecki Mariusz, Stecko Janusz, Szypuła Ireneusz

Journal of Metallic Materials

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2021

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Vol. 73, no. 1

16--21

EN

The study investigates the ability to remove copper, tin and arsenic from iron ore, scrap and liquid steel based on the literature and thermodynamic calculations using the FactSage 7.2 software. Methods of removing Cu, Sn and As from iron-bearing materials, feasible in industrial conditions in the near term, were selected. Simulation tests with the use of the FactSage 7.2 software showed that under reduced pressure conditions Cu and Sn can be removed from the steel bath, while As evaporation is not possible. Laboratory tests were carried out, including the removal of Sn and Cu in the process of degassing of liquid steel in a deep vacuum in a vacuum induction furnace and the removal of Sn from iron ore in the sintering process. Under conditions of deep vacuum (below 40 Pa), high temperature (1670°C) and a correspondingly long vacuum treatment time (over 30 minutes), the efficiency of removing the copper and tin contents from the liquid steel of approximately 14 and 17% respectively was obtained. The iron ore sintering test with a high Sn content showed the effectiveness of reducing the Sn content during this process, amounting to approx. 30%.

PL

Zbadano możliwości usuwania miedzi, cyny i arsenu z rudy żelaza, złomu i ciekłej stali na podstawie literatury oraz termodynamicznych obliczeń za pomocą oprogramowania FactSage 7.2. Wybrano sposoby usuwania Cu, Sn i As z materiałów żelazonośnych możliwe do realizacji w warunkach przemysłowych w najbliższej perspektywie czasowej. Badania symulacyjne z zastosowaniem oprogramowania FactSage 7.2 wykazały, że w warunkach obniżonego ciśnienia można usunąć Cu i Sn z kąpieli stalowej, natomiast nie jest możliwe odparowanie As. Przeprowadzono próby laboratoryjne, obejmujące usuwanie Sn i Cu w procesie odgazowania ciekłej stali w głębokiej próżni w próżniowym piecu indukcyjnym oraz usuwanie Sn z rudy żelaza w procesie spiekania. W warunkach głębokiej próżni (poniżej 40 Pa), wysokiej temperatury (1670°C) i odpowiednio długiego czasu obróbki próżniowej (powyżej 30 minut) uzyskano skuteczności usunięcia zawartości miedzi i cyny w ciekłej stali, wynoszące odpowiednio około 14 i 17%. Próba spiekania rudy żelaza z wysoką zawartością Sn wykazała skuteczność zmniejszenia zawartości Sn w czasie tego procesu, wynoszącą ok. 30%.

19

Corrosion testing of kinematic connection details from the jet engine in a seawater environment

Bogucki Karol

Journal of KONBiN

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2021

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Vol. 51, iss. 1

173--193

EN

Corrosion is a worldwide problem, posing a threat to the safe operation of machinery and equipment. In this article has been analyzed the problem of corrosion on selected elements of the aircraft engine. At the beginning, are discussed the types of corrosion, as well as the materials from which were made the examined parts. The sensitive kinematic vapor from the jet engine was examined in three different galvanic coatings and in the state without any anti-corrosion coating in order to check the effectiveness of galvanic coatings. The results of the NSS tests were then illustrated and discussed. On the basis of the obtained test results, were formulated final conclusions.

PL

Korozja jest problemem ogólnoświatowym, stwarzającym zagrożenie bezpiecznej eksploatacji maszyn i urządzeń. W niniejszym artykule problem korozji przeanalizowano na wybranych elementach silnika lotniczego. Na początku omówiono rodzaje korozji, a także materiały, z których zostały wykonane badane detale. Zbadana została newralgiczna para kinematyczna z silnika odrzutowego w trzech różnych pokryciach galwanicznych oraz w stanie bez żadnego pokrycia antykorozyjnego w celu sprawdzenia skuteczności pokryć galwanicznych. Następnie zobrazowano i omówiono wyniki badań metodą NSS. Na podstawie uzyskanych wyników badań sformułowano wnioski końcowe.

20

Scaling Behaviour of Si-alloyed Steel Slabs under Reheating Conditions

Mikl Gregor, Höfler Thomas, Gierl-Mayer Christian, Danninger Herbert, Linder Bernhard, Angeli Gerhard

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 4

71--74

EN

Reheating of steel slabs for further processing such as hot rolling usually takes place in gas-fired pusher furnaces. Temperatures well above 1000°C, combined with an atmosphere containing H2O, CO2, and O2, lead to substantial oxidation of most steel grades. Newly developed advanced steels often contain significant amounts of Si. This element plays a dominant role in the scaling behaviour near the steel-scale-interface, since fayalite (Fe2SiO4) forms a eutectic with wuestite (Fe1–xO) that melts as low as 1177°C. To better understand the high temperature oxidation behaviour, lab-scale trials were performed with different steel grades containing up to 3 wt.% Si. Possible interactions of Si with other alloying elements present in the samples such as Cr, Mn and Al were also of interest. The atmosphere contained 20% H2O, 7% CO2, and 3% O2, resembling reheating conditions in pusher furnaces, and temperatures ranged from 1100 to 1240°C. For metallographic investigation, the oxidised samples were cold mounted under vacuum using taper section angles. After preparation, the sections were examined through light microscopy, SEM/EDS, XRD, and TEM. The local distribution of the alloying elements could be mapped efficiently, and phase identification was successful in most parts. Under the applied experimental conditions, the elements of interest were present in their oxidic form either as pure or as mixed oxides. Higher Si-contents led to an increased build-up of eutectic melting phase at the steel-scale-interface at temperatures above 1177°C, which in turn further accelerated the oxidation.