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1

Effect of Post-Heat Treatment on the Impact Toughness and Crack Propagation Mechanism of AISI D2 Tool Steel Manufactured by Direct Energy Deposition

Park Jun-Hyung, Kim Kyu-Sik, Koo Yong-Mo, Kim Jin-Young, Kim Min-Chul, Lee Kee-Ahn

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

119--122

EN

This study investigated the effect of heat treatment on the microstructure and impact toughness property of AISI D2 manufactured with direct energy deposition (DED) and compared the results with conventional wrought material. The fracture crack propagation behavior was examined in connection with microstructures through fracture surface analysis. AISI D2 manufactured with DED had a eutectic structure that turned into a net-type carbide after heat treatment, and Cr-rich needle-type secondary carbide was observed. Impact toughness of DED AISI D2 measured 2.0 J/cm2 in the as-built sample and 1.1 J/cm2 in the heat-treated sample. Compared to a wrought heat-treated AISI D2, DED AISI D2 had relatively low impact toughness. DED AISI D2 and wrought material had different crack propagation mechanisms. In DED AISI D2, the eutectic structure and net-type carbide boundary were identified as the major microstructural factor decreasing impact toughness.

2

Properties and characteristics of alkali treated Calotropis gigantea fiber-reinforced particle-filled epoxy composites

Jeyapragash R., Sathiyamurthy S., Srinivasan V., Prithivirajan R., Swaminathan G.

Composites Theory and Practice

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2022

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R. 22, nr 2

99--105

EN

The presence of particles and fibers as reinforcement in a polymer matrix greatly enhances the mechanical properties. Agricultural residues and natural fibers are commonly used nowadays due to the fact that they easily decompose even after a longer period and they are eco-friendly in nature. f Fiber that was extracted from stem of Calotropis gigantea was selected as reinforcement in the present investigation. Initially the fiber was treated with a sodium hydroxide solution and CG fiber-epoxy composites were prepared. The properties of alkaline treated CG fiber-reinforced epoxy composites were further improved by the addition of particles such as chitosan, red mud and rice husk. Properties such as the tensile strength, flexural strength, impact toughness, hardness, water absorption, thickness swelling behaviour, specific wear rate and coefficient of friction were evaluated and compared. The XRD pattern of the chemically treated CG fiber-reinforced parrticle-filled epoxy composites was presented in the present study.

3

Analyzing mechanical behavior of ABS-SiO2 polymer-based nanocomposite based on ANOVA method

Afzali Mohammad, Asghari Vahid

Composites Theory and Practice

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2021

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R. 21, nr 3

61--69

EN

The fabrication of polymer-based nanocomposites by means of twin extruders is a typical method for manufacturing lightweight and high-strength structures. However, selection of the optimal parameters for this process to study the material characteristics is important. The primary aim of the present study was to ascertain the optimum extruder temperature and nanosilica content in an acrylonitrile-butadiene-styrene matrix composite. The response surface methodology was based on two factors and three levels. The identification of the effect of the parameters on the fatigue behavior of the fabricated composite was comprehensively analyzed. The results were analyzed using scanning electron microscopy (SEM). The obtained results revealed that up to 4% nano-SiO2 improves tensile strength and reduces the impact toughness. On the other hand, an increase in the extrusion temperature yields a higher impact toughness and lower tensile strength. The optimization results showed that 2.5% nanosilica and the extrusion temperature of 225°C result in the maximum tensile strength of 41 MPa, and impact toughness of 30 KJ/m2.

4

Influence of Al, Cu and Ni Additions on Mechanical Properties of Hot-Rolled Fe-9Mn-0.2C Medium-Manganese Steels

Yoon Young-Chul, Kim Sang-Gyu, Lee Sang-Hyeok, Hwang Byoungchul

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1007--1011

EN

The microstructure and mechanical properties of hot-rolled Fe-9Mn-0.2C medium-manganese steels with different Al, Cu, and Ni contents were investigated in this study. Based on the SEM, XRD, and EBSD analysis results, the microstructure was composed of martensite, band-type delta ferrite, and retained austenite phases depending on the Al, Cu, and Ni additions. The tensile and Charpy impact test results showed that the sole addition of Al reduced significantly impact toughness by the presence of delta-ferrite and the decrease of austenite stability although it increased yield strength. However, the combined addition of Al and Cu or Ni provided the best combination of high yield strength and good impact toughness because of solid solution strengthening and increased austenite stability.

5

Mikrostruktura i wybrane własności materiału zastosowanego na dyfuzor silnika samolotu odrzutowego

Dąbrowski Robert, Baran Krzysztof

Hutnik, Wiadomości Hutnicze

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2020

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Vol. 87, nr 7-8

188--195

PL

W artykule zaprezentowano wyniki badań mikrostruktury, wybranych własności mechanicznych (twardość, odporność na pękanie w warunkach dynamicznych), użytkowych (odporność na ścieranie) i fizycznych (współczynnik rozszerzalności liniowej) próbek pobranych z dyfuzora kompresora silnika samolotu, wykonanego ze stali martenzytycznej odpornej na korozję. Postawowe wskaźniki własności mechanicznych stali, z której wykonano dyfuzor kompresora wynoszą: HRC = 48, KV = 15,7 J (dla przekroju 0,4 cm2), współczynnik tarcia w zakresie 0,38 ÷ 0,57 (zależnie od czasu trwania próby), średni współczynnik rozszerzalności liniowej 14,7 ∙ 10-6 K-1 (dla zakresu przed przemianą fazową) i 22,8 ∙ 10-6 K-1 (dla zakresu po przemianie). Mikrostrukturę elementu dyfuzora w stanie obrobionym cieplnie stanowi martenzyt odpuszczony. Obserwacje fraktograficzne wskazują na mieszany charakter przełomów próbek dyfuzora użytych do badań odporności na pękanie, tj. charakter quasi - kuchy z przewagą przełomu transkrystalicznego i pewnym udziałem przełomu międzykrystalicznego.

EN

The results of microstructural studies, mechanical examinations (hardness, impact toughness), utility (resistance to wear) as well as physical (coefficient of linear thermal expansion) properties of samples taken from jet engine diffuser are presented in this paper. The diffuser was made of martensitic corrosion resistant steel. The steel is characterised by the following mechanical and physical parameters: HRC = 48, KV = 15.7 J (for cross-section of 0.4 cm2), friction coefficient 0.38 - 0.57 (depending of a test duration), average coefficient of linear thermal expansion 14.7 · 10-6 K-1and 22.8 · 10-6 K-1 for temperatures below and above phase transformation, respectively. The microstructure of the heat treated part consists of a tempered martensite. Fractographic studies has proved that a fracture of the specimen has a mixed, quasi-brittle character where transcrystalline fracture dominates over intercrystalline one.

6

Właściwości inżynierskich kompozytów cementowych zawierających granulowany żużel wielkopiecowy

Arivusudar N., Suresh Babu S.

Cement Wapno Beton

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2020

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R. 25, nr 2

95--103

PL

Inżynierskie kompozyty cementowe [IKC] n z dodatkiem włókien należą do grupy wysokowartościowych fibrokompozytów. Zawierają one drobnoziarniste składniki: cement, drobny piasek i popiół lotny, natomiast nie zawierają kruszywa grubego. Zawartość cementu w typowym inżynierskim kompozycie cementowym wynosi około 1000 kg/m3, co sprawia, że jest to materiał niezgodny z koncepcją zrównoważonego rozwoju. Popiół lotny w mieszankach IKC poprawia właściwości mechaniczne i trwałość, a optymalna ilość popiołu zastępującego cement mieści się w granicach od 30% do 40%. W przeprowadzonych badaniach podjęto próbę dodania do IKC granulowanego żużla wielkopiecowego zastępującego cement, wraz z popiołem lotnym. Przygotowano pięć mieszanek, jedną kontrolną i cztery o różnej zawartości żużla od 10% do 50%, w odstępach co 10%. Zawartość granulowanego żużla wielkopiecowego w takiej zaprawie ma korzystny wpływ na właściwości mechaniczne oraz odporność na udar.

EN

Engineered Cementitious Composites are belonging to the ultrahigh performance fiber reinforced composites. Engineered Cementitious Composites are composed of fine grained ingredients like cement, fine sand, fly ash, but don’t coarse aggregate. Presence of cement in the typical Engineered Cementitious Composites mix is nearly 1000 kilograms per cubic meter, which make this material to keep far from the sustainability. The content of fly ash in the mix improves the performance of mechanical properties and durability, however, the percentage of replacement of cement has the optimum up to 30 to 40 %. In this study, an attempt is made to add granulated blast furnace slag to Engineered Cementitious Composites mix replacing the cement, along with fly ash. Five different mix proportions are used in this investigation, from 10%, to 50%, at 10% intervals of the granulated blastfurnace slag, replacing cement. The content of granulated blast-furnace slag exhibit remarkable achievement in the mechanical parameters and impact toughness.

7

The Combined Influence of Molybdenum and Nickel in Steel Welds

Szczucka-Lasota B., Węgrzyn T., Kurc-Lisiecka A., Piwnik J.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 3

1087-1091

EN

Weld metal deposit (WMD) was carried out for standard MMA welding process. This welding method is still promising mainly due to the high amount of AF (acicular ferrite) and low amount of MAC (self-tempered martensite, retained austenite, carbide) phases in WMD. That structure corresponds with good impact toughness of welds at low temperature. Separate effect of these elements on the mechanical properties of welds is well known, but the combined effect of these alloy additions has not been analyzed so far. It was decided to check the total influence of nickel with a content between 1% to 3% and molybdenum with content from 0.1% up to 0.5%.

8

Mathemathical Equations of the Influence of Molybdenum and Nitrogen in Welds

Węgrzyn T., Kamińska J., Piwnik J., Stanik Z.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

83--86

EN

The paper offers mathematical equations of the influence of micro-jet cooling on structure and impact toughness properties of metal weld deposit. Weld metal deposit (WMD) was carried out for standard MIG welding and for MIG welding with micro-jet cooling. This new method is very promising mainly due to the high amount of AF (acicular ferrite) and low amount of MAC (selftempered martensite, retained austenite, carbide) phases in WMD. That structure corresponds with very good mechanical properties ie. good impact toughness of welds at low temperature. Micro-jet cooling after welding can find serious application in automotive industry very soon. Until that moment only argon, helium, nitrogen and gas mixtures of argon were tested for micro-jet cooling after welding. The best results of mechanical properties of WMD in presented welding method correspond with micro-jet argon cooling.

9

Influence of Rare Earth Metals on Microstructure and Mechanical Properties of G20Mn5 Cast Steel

Kasińska J.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

37--42

EN

The paper describes influence of rare earth metals (REMs) on G20Mn5 cast steel microstructure and mechanical properties. The cerium mixture of the following composition was used to modify cast steel: 49.8% Ce, 21.8% La, 17.1% Nd, 5,5% Pr and 5.35% of REMs. Cast steel was melted in industrial conditions. Two melts of non-modified and modified cast steel were made. Test ingots were subject to heat treatment by hardening (920°C/water) and tempering (720°C/air). Heat treatment processes were also performed in industrial conditions. After cutting flashes off samples of cast steel were collected with purpose to analyze chemical composition, a tensile test and impact toughness tests were conducted and microstructure was subject to observations. Modification with use of mischmetal did not cause significant changes in cast steel tensile strength and yield strength, while higher values were detected for fractures in the Charpy impact test, as they were twice as high as values for the data included in the PN-EN 10213:2008 standard. Observations performed by means of light and scanning microscopy proved occurrence of significant differences in grain dimensions and morphology of non-metallic inclusions. Adding REMs resulted in grain fragmentation and transformed inclusion shapes to rounded ones. Chemical composition analyses indicated that round inclusions in modified cast steel were generally oxysulphides containing cerium and lanthanum. In the paper the author proved positive influence of modification on G20Mn5 cast steel mechanical properties.

10

Spawanie wielkogabarytowych konstrukcji stalowych z wykorzystaniem chłodzenia mikrojetowego

Szczucka-Lasota B., Węgrzyn T., Krzysztoforski M., Fryc M.

Stal, Metale & Nowe Technologie

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2017

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nr 5-6

102--104

PL

W artykule przedstawiono nową technologię spawania stalowych konstrukcji z wykorzystaniem chłodzenia mikrojetowego. Podwyż- szono własności użytkowe spawanych konstrukcji, w tym udarność złączy spawanych w ujemnej temperaturze. Istotną zaletą spawalniczego procesu z chłodzeniem mikrojetowym jest zmniejszenie spawalniczych naprężeń cieplnych w przestrzennych konstrukcjach stalowych i pomniejszenie w nich strzałki ugięcia.

EN

A new technology of steel structures welding using microjet cooling has been presented. The usability of welded structures has increased, including the impact toughness of welded joints at negative temperatures. An important advantage of the micro-jet cooling process is the reduction of welding stresses in spatial steel structures and the reduction of their deflection.

11

Gas mixtures based on Ar-He for micro-jet cooling after MAG welding

Szczucka-Lasota B., Gajdzik B., Krzysztoforski M., Węgrzyn T., Hadryś D., Wszołek Ł.

Hutnik, Wiadomości Hutnicze

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2017

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Vol. 84, nr 7

262--265

EN

The material selected for this investigation was low alloy weld metal deposit after MAG welding with micro-jet cooling. The present investigation was aimed as the following tasks: obtained WMD with various amount of acicular ferrite in WMD in terms of helium percentage in micro-jet gas mixture. Paper focuses on low alloy steel weld properties after innovate welding method with micro-jet cooling. Weld metal deposit (WMD) for micrograph analyses and impact toughness was carried out for MAG. Until that moment only argon, helium and nitrogen were seriously tested as micro-jet gases. In that paper various gas mixtures (Ar-He) were tested for micro-jet cooling after welding. The influence of oxygen and nitrogen included in gas mixtures based on Ar-He couple on properties of WMD was also tested.

PL

Materiałem wybranym do tego badania było stopiwo uzyskane po spawaniu niestopowej stali procesem MAG z chłodzeniem mikro-jetowym. Badanie miało na celu: otrzymanie stopiwa z różną ilością drobnoziarnistego ferrytu (acicular ferrite) w zależności od zawartości helu w mieszance z argonem stosowanej do schładzania mikro-jetowego. W artykule skoncentrowano się na właściwościach złącza ze stali niestopowej po wprowadzeniu innowacyjnej metody spawania z wykorzystaniem chłodzenia mikro-jetowego. Stopiwo do badań mikrostruktury i udarności było uzyskane po spawaniu procesem MAG. Do tej pory do schładzania mikro-jetowego były dokładnie testowane tylko takie gazy jak argon, hel i azot. W tym artykule badano różne mieszanki gazowe (Ar-He) jako gazy mikro-jetowe. Na własności stopiwa badano również dodatkowy wpływ tlenu i azotu zawartego w mieszankach gazowych opartych na Ar-He.

12

Low Alloy Steel Structures After Welding with Micro-Jet Cooling

Węgrzyn T., Piwnik J., Hadryś D., Wszołek Ł.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

115--118

EN

The paper focuses on low alloy steel after innovate welding method with micro-jet cooling. Weld metal deposit (WMD) was carried out for welding and for MIG and MAG welding with micro-jet cooling. This method is very promising mainly due to the high amount of AF (acicular ferrite) and low amount of MAC (self-tempered martensite, retained austenite, carbide) phases in WMD. That structure corresponds with very good mechanical properties, ie. high impact toughness of welds at low temperature. Micro-jet cooling after welding can find serious application in automotive industry very soon. Until that moment only argon, helium and nitrogen were tested as micro-jet gases. In that paper first time various gas mixtures (gas mixtures Ar-CO2) were tested for micro-jet cooling after welding.

13

Impact Toughness of Steel WMD after TIG Welding

Węgrzyn T., Piwnik J., Stanik Z., Węgrzyn D., Sieteski D.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 3

1647--1650

EN

The material selected for this investigation was low alloy weld metal deposit after TIG welding with various amount of oxygen in weld metal deposit (WMD). After TIG process it is difficult to get proper amount of oxygen in WMD on the level much lower than 350 ppm. The highest impact toughness of low alloy WMD corresponds with the amount of oxygen in WMD above 350 ppm. In the paper focuses on low alloy steel after innovate welding method with micro-jet cooling that could be treated as a chance on rising amount of oxygen in weld. Weld metal deposit (WMD) was carried out for TIG welding with micro-jet cooling with various amount of oxygen in WMD. In that paper various gas mixtures (gas mixtures Ar-O2 and Ar-CO2) were tested for micro-jet cooling after TIG welding. An important role in the interpretation of the results can give methods of artificial intelligence.

14

Effect of Heat Treatment on Microstructure and Impact Toughness of Ti-6Al-4V Manufactured by Selective Laser Melting Process

Lee K.-A., Kim Y.-K., Yu J.-H., Park S.-H., Kim M.-C.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2B

1341--1346

EN

This study manufactured Ti-6Al-4V alloy using one of the powder bed fusion 3D-printing processes, selective laser melting, and investigated the effect of heat treatment (650°C/3hrs) on microstructure and impact toughness of the material. Initial microstructural observation identified prior-β grain along the building direction before and after heat treatment. In addition, the material formed a fully martensite structure before heat treatment, and after heat treatment, α and β phase were formed simultaneously. Charpy impact tests were conducted. The average impact energy measured as 6.0 J before heat treatment, and after heat treatment, the average impact energy increased by approximately 20% to 7.3 J. Fracture surface observation after the impact test showed that both alloys had brittle characteristics on macro levels, but showed ductile fracture characteristics and dimples at micro levels.

15

Effect of Different Inoculants on Impact Toughness in High Chromium Cast Iron

Siekaniec D., Kopyciński D., Guzik E., Tyrała E., Nowak A.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 2

85--88

EN

The present work, presented the study of effect of different inoculants on impact toughness in High Chromium Cast Iron. The molds were pouring in industrial conditions and samples were tested in laboratory in Faculty of Foundry Engineering at AGH. Seven samples were tested - one reference sample, three with different addition of Fe-Ti, and three with different addition of Al. The samples were subjected to impact toughness on Charpy hammer and the hardness test. The presented investigations indicate that for the each inoculant there is an optimal addition at which the sample obtained the highest value of impact toughness. For the Fe-Ti it is 0.66% and for Al is 0.17%. Of all the examined inoculants best results were obtained at a dose of 0.66% Fe-Ti. Titanium is a well-known as a good modifier but very interesting results gives the aluminum. Comparing the results obtained for the Fe-Ti and Al can be seen that in the case of aluminum hardness is more stable. The hardness of all samples is around 40-45 HRC, which is not high for this type of cast iron. Therefore, in future studies it is planned to carry out the heat treatment procedure that may improves hardness.

16

The use of compressed air for micro-jet cooling after MIG welding

Hadryś D., Węgrzyn T., Piwnik J., Stanik Z., Tarasiuk W.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 3

1405--1408

EN

The material selected for this investigation was low alloy steel weld metal deposit (WMD) after MIG welding with micro-jet cooling. The present investigation w*as aimed as the following tasks: obtained WMD with various amount of acicular ferrite and further analyze impact toughness of WMD in terms of acicular ferrite amount in it. Weld metal deposit (WMD) was first time carried out for MIG welding with micro-jet cooling of compressed air and gas mixture of argon and air. Until that moment only argon, helium and nitrogen were tested as micro-jet gases for MIG/MAG processes. An important role in the interpretation of the results can give methods of artificial intelligence.

17

Compressive Strength of Steel Frames after Welding with Micro-Jet Cooling

Hadryś D., Węgrzyn T., Piwnik J., Wszołek Ł., Węgrzyn D.

Archives of Metallurgy and Materials

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2016

|

Vol. 61, iss. 1

123--126

EN

Low carbon steel weld structures generally exhibit a very linear stress-strain relationship. In the study of strength of materials, the compressive strength is the capacity of a material or structure to withstand loads tending to reduce size of structure. It is mainly measured by plotting applied force against deformation in a testing machine. Compressive strength is a main key value for design of welded structures.The main goal of that paper was analysing of plastic properties of frame welds which were made with various parameters of micro-jet cooling. New technology of micro-jet welding could be regarded as a new way to improve plastic properties of welds. It allows to obtain welds with better mechanical properties in comparison to ordinary welding method. Furthermore it is possible to steering of weld structure and properties of the weld. There were given main information about influence of various micro-jet gases on metallographic and properties of structure steel welds.

18

Micro-jet Cooling by Compressed Air after MAG Welding

Węgrzyn T., Piwnik J., Tarasiuk W., Stanik Z., Gabrylewski M.

Archives of Foundry Engineering

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2016

|

Vol. 16, iss. 2

111--114

EN

The material selected for this investigation was low alloy steel weld metal deposit (WMD) after MAG welding with micro-jet cooling. The present investigation was aimed as the following tasks: analyze impact toughness of WMD in terms of micro-jet cooling parameters. Weld metal deposit (WMD) was first time carried out for MAG welding with micro-jet cooling of compressed air and gas mixture of argon and air. Until that moment only argon, helium and nitrogen and its gas mixture were tested for micro-jet cooling.

19

Enhancing the properties of friction stir welded stainless steel joints via multi-criteria optimization

Lakshminarayanan A. K.

Archives of Civil and Mechanical Engineering

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2016

|

Vol. 16, no. 4

605--617

EN

An attempt is made to establish empirical relationships to predict the properties of friction stir welded stainless steel joints. The process parameters namely, rotational speed, welding speed and shoulder diameter and the properties such as tensile strength, notch tensile strength, impact toughness and degree of sensitization are considered. The investigated properties are correlated with the macrostructure and microstructural characteristics of different zones of FSW joints to understand the influence of process parameters. Multi-criteria optimization is used to obtain optimum welding conditions that can yield enhanced properties of FSW joints. The optimized results indicated that, the properties can be enhanced with the use of rotational speed of 441 rpm, welding speed of 118 mm/min, and shoulder diameter of 17.5 mm. This is mainly due to very fine stir zone grain structure in the order of 5.5 μm and the presence of thin layer of banded structure at the advancing side of fabricated joints under optimum parameters.

20

Deformation and energy parameters of fracture of steel of the main gas pipeline

Maruschak P, Panin S, Polyvana U, Vuherer T., Guzanová A., Brezinová J.

Advances in Science and Technology. Research Journal

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2015

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Vol. 9, nr 28

40--46

EN

By example of steel 17G1S, the regularities in the impact fracture of Charpy specimens at normal and low temperatures are described. The relationship between the energy parameters of fracture (impact toughness) and the deformation response of the material (the height of shear lips) of the specimens from the pipe steel is established. The micromechanisms of impact fracture of the material are described. At 20 °C and –30 °C, focal splitting of the material was observed on the fracture surface of specimens; at –60 °C, the material failed in a brittle manner by the mechanism of cleavage.