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1

Analysis of the linear expansion coefficient of S355J2 and C45 steel specimens welded by MIG, MMA and TIG techniques

Kud Bartłomiej, Fejkiel Romuald

Advances in Mechanical and Materials Engineering

|

2026

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Vol. 43, nr 1

179--189

EN

Knowledge of the linear expansion coefficient of steel is crucial for ensuring the safety, durability, and proper functioning of welded structures. The aim of this study is to investigate the coefficient of linear expansion of S355J2 structural steel and C45 carbon steel, welded using various techniques: metal inert gas welding, tungsten inert gas welding and manual metal arc welding. Linear expansion tests of steel samples were conducted using a dilatometer. The results allowed for an assessment of the effect of the welding technique and the chemical composition (carbon content) of the steel on the thermal properties of the test materials. The reference samples (materials in as-received state) achieved the highest level of thermal expansion. All welding techniques reduced the temperature-induced elongation, with the magnitude of this effect dependent on the welding technique used. The results have practical implications for the design of structural components exposed to variable temperature conditions. Understanding the effect of individual welding techniques on the properties of S355J2 and C45 steels can support the selection of material welding technologies where dimensional stability is an important quality parameter.

PL

Znajomość wartości współczynnika rozszerzalności liniowej stali ma kluczowe znaczenie w zapewnieniu bezpieczeństwa, trwałości i poprawnego działania konstrukcji spawanych. Celem niniejszej pracy jest zbadanie współczynnika rozszerzalności liniowej stali konstrukcyjnej S355J2 oraz stali węglowej C45, spawanych różnymi metodami: elektrodą topliwą w osłonie gazów obojętnych, nietopliwą elektrodą wolframową w osłonie gazów obojętnych oraz metodą łukowego spawania elektrodą otuloną. Badania rozszerzalności liniowej przeprowadzono z wykorzystaniem dylatometru. Wyniki pozwoliły na ocenę wpływu metody spawania oraz składu chemicznego (zawartości węgla) stali na właściwości termiczne badanych materiałów. Próbka referencyjna (materiał w stanie dostawy) osiągnęła najwyższy poziom rozszerzalności cieplnej. Wszystkie zastosowane metody spawalnicze prowadziły do zmniejszenia wydłużenia wywołanego zmiana temperatury, przy czym skala tego efektu była uzależniona od użytej techniki spawania. Uzyskane wyniki mają praktyczne znaczenie w kontekście projektowania elementów konstrukcyjnych narażonych na zmienne warunki temperaturowe. Zrozumienie wpływu poszczególnych metod spawania na właściwości stali S355J2 i C45 może wspomagać wybór technologii łączenia materiałów tam, gdzie stabilność wymiarowa jest ważnym parametrem jakościowym.

2

Influence of corrosion on the fatigue resistance of a carbon steel with Ti and Cr nitrides based coatings

Vicen Martin, Zatkalíková Viera, Bokůvka Otakar, Nový František, Belan Juraj, Nikolic Ružica

System Safety : Human - Technical Facility - Environment

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2025

|

Vol. 7, iss. 1

295--304

EN

The quality of components and structures is directly related to degradation processes such as corrosion and fatigue that are concomitant phenomena during their operation. One of the options for increasing the quality of components and structures is the use of appropriate surface coating. In this paper is presented an experimental investigation of the corrosion influence on the fatigue resistance of the carbon steel with coatings based on Ti and Cr nitrides. The experimental work included determination of the chemical composition of the base material, heat treatment, microstructure evaluation, mechanical properties measurement, coating depositions, corrosion test and the fatigue tests by rotation bending of the deposited layers. The corrosion and fatigue tests have shown that the coating provides improvement of the corrosion resistance and that there was no reduction of the fatigue resistance.

3

Macrosegregation of Carbon in Heavy Steel Casting

Pernica Vítězslav, Záděra Antonin, Kaňa Václav, Krutiš Vladimír

Archives of Metallurgy and Materials

|

2025

|

Vol. 70, iss. 1

285--290

EN

Segregation of elements during solidification of massive steel castings and ingots is caused by their different solubility in the melt and in the newly formed solid phase. The macrosegregation of elements significantly affects the structure in terms of microstructure and macrostructure of the casting as well as on its mechanical and operational properties. This paper deals with the evaluation of macrosegregation of selected elements on a real cross-section of a heavy experimental carbon steel casting. Macrosegregation of elements was determined by spectral analysis at selected locations and compared with the ProCAST software and its results of casting solidification simulation. The macrosegregation was analysed along the height and width of a cross-section of the casting, which measured approximately 1800×600×100 mm. Over 300 points were analysed in this area of the casting. The results present mainly carbon segregation. The carbon segregation is compared to the solidification conditions expressed by the cooling rate and the time between the liquidus and solidus temperatures (mushy zone). The aim of this paper was also to verify the measured results with those calculated using commercial software. In conclusion, the measured macrosegregation of the carbon in the casting is different from the simulated macrosegregation, this fact is not negligible. The difference in measured carbon content is influenced by solidification kinetics and will significantly affect the material properties.

4

Structure and mechanical properties of cermet Ni-Al/MSZ thick coating prepared by flame spraying technique

Saleh Mahmood M., Khemakhem Hamadi, Jassim Ismel K., Al-Saqa Read Hashim

Ochrona przed Korozją

|

2024

|

nr 1

9--14

EN

The aim of this study was to obtain a thick protective cermet coating on API 5L (carbon steel) pipes, used in the oil industry. A new method involving flame spray coating has been selected to produce thick ceramic-metal coatings of Ni-Al/MgO-ZrO2 under optimal spraying parameters. Structural properties were measured by X-ray diffraction (XRD). Morphology was determined by means of scanning electron microscopy (SEM). The elemental composition in the cermet coating was confirmed by energy dispersive spectroscopy (EDS). Deposition efficiency was found to be an important factor as demonstrated by adhesion force results obtained using the pull-out tensile test. The results show that the best spray distance is 20 cm, as it ensures good interaction between the layers, a high adhesion force value of 8.4 MPa, a uniform microstructure, low porosity, a hardness of 166.4 HV, and a coating thickness of approximately 1.85 mm. X-ray results clearly show that the cermet coating consists of numerous phases, such as tetragonal (T), monoclinic, and face center cubic (FCC). SEM images revealed that the typical particle-containing microstructures consisted of spherical shapes with elongated agglomerations. Finally, based on the results obtained, it can be concluded that flame spray coating provides a significant improvement in performance.

PL

Celem pracy było uzyskanie grubej ochronnej powłoki cermetalowej na rurach API 5L (ze stali węglowej), stosowanych w przemyśle naftowym. Wybrano nową metodę natryskiwania płomieniowego w celu wytworzenia grubych powłok ceramiczno-metalowych Ni-Al/MgO-ZrO2 przy optymalnych parametrach natryskiwania. Właściwości strukturalne zostały zmierzone za pomocą dyfrakcji rentgenowskiej (XRD). Morfologię określono za pomocą skaningowej mikroskopii elektronowej (SEM). Skład pierwiastkowy powłoki cermetalowej ustalono, używając spektroskopii dyspersji energii (EDS). Stwierdzono, że wydajność osadzania jest ważnym czynnikiem, o czym świadczą wyniki pomiaru siły adhezji uzyskane w próbie rozciągania. Z badań wynika, że najlepsza odległość natryskiwania wynosi 20 cm – zapewniona jest wówczas dobra interakcja między warstwami, wysoka wartość siły adhezji: 8,4 MPa, jednolita mikrostruktura, niska porowatość, twardość wynosi 166,4 HV, a grubość powłoki ok. 1,85 mm. Badania rentgenowskie pozwoliły ustalić, że powłoka cermetalowa składa się z wielu faz: tetragonalnej (T), jednoskośnej i FCC. Obrazy SEM ujawniły, że typowe mikrostruktury zawierające cząstki składały się z kulistych struktur tworzących wydłużone aglomeracje. Na podstawie uzyskanych wyników można stwierdzić, że zastosowana metoda natryskiwania płomieniowego zapewnia znaczną poprawę właściwości ochronnych.

5

Study on the microstructure and technological properties of clad plates made of steels S235jR and X20Cr13 and S235jR and X5CrNi18-10 after hot rolling

Walnik Bartłomiej, Woźniak Dariusz, Adamczyk Mariusz, Palus Rafał, Bagińska Aleksandra

Materials Science and Welding Technologies / Technologie Materiałowe i Spawalnicze

|

2024

|

Vol. 68, No. 3

art. no. 1

EN

The article presents the results of physical experiments consisting in the rolling of layered plates (clad plates). The experiments involved two types of two-layered flat bars, i.e. S235JR and X20Cr13 as well as S235JR and X5CrNi18-10. The experiment resulted in the development of a technology for the fabrication of layered flat bars made of structural steel S235JR, corrosion-resistant steel X20Cr13 and austenitic acid-resistant steel X5CrNi18-10. Microstructural observations were performed using a light microscope (LM) and a scanning electron microscope (SEM). The observations revealed the possibility of obtaining permanent joints through hot rolling and the possibility of applying steel grades S235JR, X20Cr13 and X5CrNi18 in the fabrication of layered plates.

PL

W artykule omówiono wyniki fizycznych eksperymentów walcowania blach warstwowych. Eksperymenty wykonano na dwóch rodzajach płaskowników dwuwarstwowych S235JR – X20Cr13 i S235JR – X5CrNi18-10. Wynikiem eksperymentów było opracowanie technologii wytwarzania płaskowników o budowie warstwowej, złożonych ze stali konstrukcyjnej S235JR oraz ze stali odpornej na korozję X20Cr13 i stali kwasoodpornej austenitycznej X5CrNi18-10. Badania mikrostruktury przeprowadzono przy użyciu techniki mikroskopii świetlnej i skaningowej mikroskopii elektronowej, SEM. Wyniki pracy wskazują, że dobrane parametry walcowania na gorąco pozwoliły na wytworzenie trwałego połączenia pomiędzy blachami w wyniku ich walcowania na gorąco i na możliwość zastosowania stali z gatunków S235JR, X20Cr13 i X5CrNi18 na blachy warstwowe.

6

Study on Corrosion Behavior of Sour Water Stripper in Ammonium Chloride by Electrochemical Techniques

Jin Shi, Chen Guanyu, Huang Xin, Ou Guofu

Archives of Metallurgy and Materials

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2024

|

Vol. 69, iss. 2

507--513

EN

The corrosion features of 20# carbon steel, the base material of sour water stripper, in NH4Cl solution were examined in this research. The anatomical samples of the corroded parts were characterized by an X-ray diffractometer and other analytical tools. It was found to be a localized perforation caused by pitting, and the corrosion product was FeCl2. 20# steel was subjected to electrochemical testing using Tafel polarization and Electrochemical impedance spectroscopy. The studies showed that the 20# steel’s cathodic depolarization reaction rate speeds as density rises, and that the concentration polarization gets more marked as temperature rises. The corrosion rate of 20# steel is the fastest when temperature hits its highest point of 80°C, measuring 4.7142 mm/a. When density rose from 5 to 20%, corrosion rate grew from 1.6378 to 7.2430 mm/a.

7

Optimization of mechanical performance in arc and TIG welding joints via advanced thermal treatment techniques

Ali Aenas L., Obaid Zuhair H.

Archives of Engineering Knowledge

|

2024

|

T. 10, Nr 1

109--113

EN

Welding is one of the most important industrial processes, and many techniques have been developed to achieve efficient and low cost welding of various metals. This research aims to compare two common welding methods, conventional arc welding (Arc Welding) and shielding gas arc welding (TIG Welding), when applied to low carbon steel. Mechanical tests were conducted, including tensile testing and hardness measurement, in addition to microstructure analysis through photographic documentation. The results showed that the maximum tensile strength of the arc-welded sample was 25.5% higher than that of the unwelded metal, while the tensile strength of the TIG-welded sample was 9.5% lower. In terms of hardness, the highest value of TIG welding was about 300 HV, compared to 250 HV for conventional arc welding, indicating that TIG welding produces a microstructure with higher hardness but at the expense of tensile strength. It was also found that post-welding heat treatment improved the mechanical properties of both methods, enhancing their strength and operational characteristics. These results provide important guidance for selecting the appropriate welding method based on mechanical requirements, with arc welding being preferred when high tensile strength is required, while TIG welding is more suitable for applications requiring higher hardness and greater corrosion resistance.

8

Effects of incorporation of nanotitania in magnesium phosphate cement for the protection of carbon steel in harsh environments

Sujitha V. S., Ramesh B., Xavier Joseph Raj

Archives of Civil and Mechanical Engineering

|

2024

|

Vol. 24, no. 2

art. no. e79, 2024

EN

Corrosion is a major challenge to ensuring the durability and structural integrity of steel structures, particularly under harsh environmental conditions. In this work, we explored the possibility of incorporating nanotitania (TiO2) into magnesium phosphate cement (MPC) coatings to improve the corrosion resistance of low-carbon steel (LCS). Magnesium phosphate cement (MPC) has great potential to replace conventional organic coatings because of its corrosion resistance and sustainability. Titanium dioxide (TiO2) nanoparticles are included in the MPC coating to protect steel structures from corrosion because of their effectiveness in preventing them from decreasing the lifespan of steel. The material characterization of the MPC/TiO2 coatings was conducted using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) methods. Tafel polarization and electrochemical impedance spectroscopy (EIS) were used to assess the corrosion resistance of the coated and uncoated samples in a 3.5% NaCl solution. EIS measurements revealed that the MPC/TiO2 coatings, particularly those containing 10% TiO2, exhibited superior anti-corrosion properties. The resistance (Rcoat) measured for this coating was 1.22E10 Ω cm2, and the charge transfer resistance (Rct) reached 1.50E12 Ω cm2, demonstrating remarkable corrosion protection. The accelerated corrosion test proves that the inclusion of 10% nanotitania in the MPC controls the delamination of the coating. Additionally, the adhesion strength of 18.1 MPa for the MPC/10TiO2 coating confirms the durability of the coating. Only a small percentage of weight loss and adhesion loss were observed after 28 days of immersion in a corrosive NaCl environment, demonstrating the long-term durability of the MPC/TiO2 coatings. The findings of this study indicate that adding 10% TiO2 to MPC coatings has enormous potential for improving the corrosion resistance of LCSs. This cementitious coating material offers an effective way to reduce early oxidation in steel buildings, making it a useful tool in construction projects intended to ensure the prolonged lifespan of LCS components.

9

Application of regression models on the prediction of corrosion degradation of a crude oil distillation unit

Varbai Balázs, Wéber Richárd, Farkas Balázs, Danyi Péter, Krójer Antal, Locskai Roland, Bohács György, Hős Csaba

Advances in Materials Science

|

2024

|

Vol. 24, nr 1(79)

72--85

EN

The crude distillation unit is the most critical elements in the refining process. Moreover, most of the equipment in the distillation unit are made of general carbon steels. Data analysis models, machine learning techniques can predict corrosion degradation rates. We used Pearson’s correlation coefficient and multiple linear regression, to predict the impact of process parameters. Altogether, we have analysed 84 channels of technological parameters, and 22 different types of crude oils. Among the corrosion agents, the chloride content strongly affected the weight loss of coupons, where the highest coefficient was 0.68. The most influential parameter is found to be the pH value. Thus, an estimation method of the pH value is set up to predict the corrosion degradation rate. The regression correlation for estimating the pH value is 0.53 if the corrosion agents are not used, which can be improved to 0.76 if the corrosion agents are also used in the regression analysis.

10

Influence hot plastic deformation on the structure and properties of carbon steel of the railway wheel

Vakulenko Igor, Plitchenko Sergey, Bolotova Dariy, Asgarov Khangardash

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2023

|

z. 121

257--266

EN

The study is devoted to the explanation of the influence of hot plastic deformation on the properties of railway wheels. The shape of individual elements of the wheel provides for a different degree of hot compression, which determines the mechanism for the development of the recrystallization at austenite. With a decrease in the degree of the hot deformation, a certain proportion of grains with a low energy of linear stretching are formed in austenite. As a result, of the low mobility of such boundaries, the likelihood of preservation of part of the substructural state of the austenite increases, which should affect the formation of a colony of perlite during the cooling of the carbon steel. Against background preservation and a dependence of strength properties on the dispersion of the pearlite colony, the appearance in austenite of grain boundaries with a low energy of linear tension leads to a qualitative change in the plastic properties of railway wheel steel. The increase in plasticity of carbon steel with an increase in dispersion of the pearlite colony is due to a decrease in the effect of solid solution hardening and an increase in the role of the ferrite-cementite interface in the development processes of strain hardening carbon steel. The results obtained can be useful for improving the technology of manufacturing all-rolled railway wheels.

11

XRD and STA Characterization of Phosphate Layers Deposited on the Carbon Steel Surface

Burduhos-Nergis Diana Petronela, Bejinariu Costica, Cazac Alin Marian, Sandu Andrei Victor, Vizureanu Petrica

Archives of Metallurgy and Materials

|

2023

|

Vol. 68, iss. 3

955--960

EN

Carbon steel is one of the most widely used alloys in many industries, however, its use is limited by its low corrosion resistance. Depositing a layer of phosphate on its surface improves the corrosion resistance as well as other properties, such as wear resistance, adhesion etc. Accordingly, preliminary studies demonstrated that carbon steel coated with phosphate layers can be used in the manufacture of carabiners for various fields: civil engineering, oil industry etc. Whereas, to demonstrate their capacity to operate in severe conditions related to fire rescue and extinguishing operations, it is necessary to evaluate the thermal behaviour of these materials. Thus, the main goal of this paper is to study the behaviour at high temperatures of three different types of phosphate layers deposited on carbon steel surface, by STA analysis. Also, the paper aims to study the formation of different phosphate layers by determining the types of compounds formed after the completion of the phosphating process, by XRD analysis.

12

Microstructure and Mechanical Properties of AISI 1106 /AISI 1045 Steels Drawn Arc Stud Welded Joints

Algodi Samer Jasim, Salman Abdulhakeem Amer, Al-Helli Ali H.

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 5

48--55

EN

Arc stud welding process was used to join a fully threaded low carbon steel AISI 1106 stud to medium carbon steel AISI 1045 plate, the effects of welding current 200, 400 A and the welding time 0.1 to 0.6 step 0.1 s on the microstructure and mechanical properties were investigated, additional parameters of adding 0.1, 1 g SiC powder and applying nano carbon layer to the welding area also included. The results demonstrate that the preferred stud welding process parameters for this system was 400 A with 0.4 s welding current and time, respectively, which has a maximum tensile strength of 583 MPa. The joints fabricated with ash and nano carbon coated at preferred welding parameters showed a slight reduction in tensile strength. The fracture of the tensile test specimen consists of three failure modes including of interface fracture between stud and plate surface due to incomplete melting at low processing parameter, pullout fracture which is featured by a hole in the plate surface and fracture at the stud shank instead of the weldment interface or heat affected zone. The microstructure of the stud and plate are characterized by equiaxed grain of ferrite and pearlite with small amount of ferrite, respectively. The fusion zone consists of fine grain of ferrite and perlite. The hardness of the fusion zone was recording 132 HV which it slightly higher than the stud hardness 128 HV and lower than that of plate of 164 HV.

13

Influence structure on the plasticity of carbon steel of the railway wheel rim in operation

Vakulenko Igor Alex, Vakulenko Leonid, Bolotova Dariy, Kurt Bulent, Asgarov Hangardash, Çölova Ömer

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2022

|

z. 115

183--192

EN

When simulating the operating conditions of the rim of a railway wheel, an analysis of change in the structural state from the possible degree of plastic deformation and the heating temperature of steel near the rolling surface was carried out. The development processes of spheroidization and coalescence of cementite during heating of the cold-worked steel change its ability to strain hardening. Substructure changes during heating to temperatures of 500-550°C deformed steel are accompanied by a simultaneous decrease in its ability to strain hardening and the level of plasticity. When heated above 500-550°C, the development of ferrite recrystallization processes provides a gradual transition of the metal from substructure hardening to hardening from grain boundaries with large angles of disorientation. It is shown that regardless of the nature of the main structural element, the ability of steel to strain hardening and the level of plasticity after heating are related by a proportional relationship.

14

Influence of Adhesive Compound Viscosity on the Strength Properties of 1.0503 Steel Sheets Adhesive Joints

Miturska-Barańska Izabela, Rudawska Anna

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no. 2

196-205

EN

The presented study concerned the comparison of the adhesive joints strengths of 1.0503 carbon steel sheets of higher quality, which were made using adhesive compounds characterized by different viscosity index of the components. Three types of commercial epoxy resins were used: Epidian 5, Epidian 53 and Epidian 57, as well as two types of curing agents: polyamide (PAC) and amine (Z-1). The surfaces of the test specimens were subjected to a pre-treatment operation in the process of a mechanical machining with an abrasive coated tool of P320 gradation. The surface roughness measurements were carried out as a control. The single-lap adhesive joints were the subject of the strength testing. The strength tests carried out on a Zwick/Roell Z150 testing machine concerned the comparison of the strength of the adhesive joints loaded in shear. Statistical analysis was performed on the results obtained. It was observed, among others, that the adhesive joints prepared with the epoxy adhesive compounds containing the polyamide curing agent showed much higher the shear strength than the adhesive joints made with the epoxy adhesive compounds containing the amine curing agent. Moreover, the use of the polyamide curing agent in the adhesive compounds with the epoxy resins resulted in formation of a more elastic adhesive layer, for which higher elongation was observed than in the case of the epoxy compound with the amine curing agent.

15

Effect of addition of non-functionalized graphene oxide in a commercial epoxy resin used as coating

Varela Caselis Jenaro Leocadio, Santamaría Juárez Juana Deisy, Galicia Aguilar José Alberto, Domínguez Alcalá María Fernanda, Rubio Rosas Efraín, Mendoza Hernández José Carlos, Sánchez Cantú Manuel

Materials Science Poland

|

2021

|

Vol. 39, No. 4

467--477

EN

The paper studies the effect of incorporating graphene oxide (GO) without surface functionalization on a commercial epoxy resin. GO was dispersed in a commercial epoxy resin at concentrations of 0 wt.%, 0.1 wt.%, 0.5 wt.%, 1 wt.%, and 3 wt.%. The resultant materials were deposited on carbon steel substrates, followed by the use of a 5 wt.% aqueous NaCl electrolyte, to evaluate the effectiveness of their anticorrosive coating function. Scanning electron microscopy (SEM) analysis showed that the GO was homogenously dispersed in the polymer matrix, resulting in flat and smooth surfaces. The X-ray diffraction (XRD) results showed that although GO was highly dispersed in the polymer matrix, multilayer graphene was also obtained after curing. The anticorrosive properties were evaluated by electrochemical impedance spectroscopy (EIS) at various exposure periods. Analysis of the prepared samples indicated that the best anticorrosion performance among them was available with the 0.5 wt.% GO coating. The obtained results indicate that GO–polymer matrix composites provide improved corrosion protection properties even after 500 h exposure to the NaCl solution.

16

Model wymiany ciepła w procesie ciągłego odlewania stali z uwzględnieniem lokalnego warunku brzegowego

Rywotycki Marcin, Hadała Beata, Malinowski Zbigniew

Hutnik, Wiadomości Hutnicze

|

2021

|

Vol. 88, nr 3-4

19--22

PL

W pracy przedstawiono obliczenia symulacyjne pola temperatury wykonane dla wlewka płaskiego ze stali węglowej. Modelowano proces ciągłego odlewania pasma o szerokości 1500 mm i wysokości 225 mm. W symulacjach numerycznych założono trzy warianty warunku brzegowego wymiany ciepła. W pierwszym wariancie współczynnik wymiany ciepła w każdej strefie chłodzenia zależał od temperatury powierzchni i gęstość strumienia wody bez uwzględnienia istnienia rolek. Drugi model warunku brzegowego definiował współczynnik wymiany ciepła wokół każdej dyszy natryskowej również bez uwzględnienia wymiany ciepła z rolkami. Ostatnim wariantem obliczeń był model, w którym uwzględniono lokalny współczynnik wymiany ciepła wynikający z zastosowanego układu chłodzenia oraz kontaktu z rolkami podtrzymującymi i ciągnącymi. Analizie poddano pole temperatury otrzymane w wyniku obliczeń dla trzech przyjętych wariantów warunków brzegowych. Warunek brzegowy, który uwzględnia ułożenie dysz oraz rolek pozwolił uzyskać bardziej nierównomierne, bliższe rzeczywistemu pole temperatury. Zastosowanie modelu najbardziej rozbudowanego pozwala z dużą dokładnością wyznaczyć pole temperatury na powierzchni krzepnącego pasma w maszynie COS.

EN

The calculations of ingot temperature field, which was made for carbon steel slabs were presented. The dimension of the ingot was 1500 mm wide and 225 mm high. In the numerical simulations, three models of the boundary condition of the heat transfer were used. In the first one, the heat transfer coefficient in the secondary cooling zones was calculated as a function of surface temperature and water jet density. In the second model the heat transfer coefficient is defined around each spray nozzle. In the first and second model contact with the rolls was neglected. The last variant of the calculations has been done for local heat transfer coefficient (model 2) and the contact with rolls was included. The simu-lation results for three models have been analysed. Model with the boundary condition, which takes into account the position of nozzles and rolls, has given the most accurate results of temperature fields in the continuous casting process. The calculations have been performed using self-developed software which uses the inverse method and FEM.

17

Wear-Fatigue Study of Carbon Steels

Hejwowski Tadeusz, Szala Mirosław

Advances in Science and Technology. Research Journal

|

2021

|

Vol. 15, no. 3

179--190

EN

The process of conjoined stress cycling and abrasive or erosive wear is encountered in industry. However, very scant attention has been paid till now to this issue. The paper presents two test rigs designed and built to cope with this experimental problem. Tests were carried out on the range of pure iron (Armco), carbon steels namely S235JR, C45, C70U, C80U, C110U and unalloyed cast steels (L40III, L45III and L50III). Tested iron-based alloys differ in chemical composition, microstructure and Brinell hardness ranging from 80HB to 350HB. Stress cycling caused strain hardening of ferrite in hypoeutectoid steels and thus reduced their abrasive wear loss. In the hypereutectoid steel stress cycling impaired integrity of the microstructure thus increasing abrasive wear loss. Alternating stresses enhanced ploughing and cutting micromechanisms of erosion. Tensile stress in the tested cast steel had a stronger effect on wear loss than the prior stress history.

18

Electrochemical and Quantum Chemical Investigation on Adsorption of Nifedipine as Corrosion Inhibitor at API 5L X-52 Steel / HCl Acid Interface

Ikpi M. E., Abeng F. E.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 1

125--131

EN

Nifedipine, a pyridine derivative was investigated as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution by potentiodynamic polarization, electrochemical impedance spectroscopy and quantum chemical calculations. Statistical tools were used to compare results of the experimental methods. The results showed that nifedipine is capable of inhibiting the corrosion of API 5L X-52 steel in 2 M HCl solution. Potentiodynamic polarization results reveal that nifedipine functions as a mixed-type inhibitor and presents an inhibition efficiency of about 78% at 500 ppm. Impedance data reveal an increasing charge transfer resistance with increasing inhibitor concentration and also shows comparable inhibition efficiency of about 89-94% at 500 ppm. Thermodynamic parameters imply that nifedipine is adsorbed on the steel surface by a physiochemical process and obeys Langmuir adsorption isotherm. The calculated molecular properties namely the highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy, chemical hardness, energy gap, dipole moment, electronegativity and global nucleophilicity index all show a positive relationship to the observed corrosion inhibition efficiency.

19

Corrosion Inhibition of API 5L X52 Carbon Steel by 1-Ethyl-3-methylimidazolium-methanesulphonate and 1-Ethyl-3-methylimidazolium Acetate Ionic Liquids in Hydrochloric Acid

Ikpi Magdalene Edet, Obono Okama Ebri

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 1

295--304

EN

The corrosion inhibition behaviour of 1-Ethyl-3-methylimidazolium-methanesulphonate (EMIM[MS]) and 1-Ethyl-3-methylimidazolium acetate (EMIM[Ac]) on API 5LX-52 carbon steel in 2 M HCl was investigated using weight loss, potentiodynamic polarization and electrochemical impedance methods. The corrosion rates of carbon steel decreased in the presence of these ionic liquids. The inhibition efficiencies of the compounds increased with concentration and showed a marginal decrease with a 10°C increase in temperature. Polarization studies showed the compounds to be mixed type inhibitors with stronger anodic character. The adsorption mechanism of both compounds on the metal surface was via physical adsorption and the process obeyed the El-Awardy kinetic-thermodynamic model. The associated activation energy of corrosion and other thermodynamic parameters were calculated to elaborate on the thermodynamics and mechanism of the corrosion inhibition process. EMIM[MS] was found to inhibit the corrosion of carbon steel better than EMIM[Ac] and is attributed to the presence of the highly electronegative sulphur atom in its structure and its larger molecular size.

20

Insights into factors of damage of surface rolling of railway wheels during operation

Aaskerov Hangardas, Vakulenko Igor, Grischenko Nikolaji

Zeszyty Naukowe. Transport / Politechnika Śląska

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2019

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z. 105

27--33

EN

The systematization results of microstructure studies of carbon steel has made it possible to explain the mechanism of formation of certain damages to the rolling surface of railway wheels during operation. The evaluation ability of metal to strain hardening was used to explain the nature of the influence compactly located non-deformable dispersed particles on the strength properties steel during cold plastic deformation. In the process of the interaction of a railway wheel with a rail, successively occurring heterogeneities in the distribution of the plastic flow metal are one of the main reasons for the formation of defects on the rolling surface of the wheel.