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1

Characterization of galvanized steel-low alloy steel arc stud welded joint

Abbas S. J., Alali M., Abbas M. H., Abbas W. S.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 117, nr 2

79--85

EN

Purpose This paper investigates the possibility of successfully welding a Low Alloy Steel (LAS) stud to Galvanized Steel (GS) plate. Design/methodology/approach Arc Stud Welding (ASW) was performed on joining LAS studs to GS plates. Welding parameters were selected based on weld trails. The first tests of the welded joints were based on visual inspection for welding defects such as lack of fusion and undercut welding defects. The good quality should be free of these defects and have full weld reinforcement. Other weld qualifications included torque strength test, microhardness test, and microstructure examination. Findings The LAS studs have been successfully welded to a galvanized steel plate using the arc stud welding process. Higher welding current with adjusted welding time (800 A, 0.3 s) gave full weld reinforcement, the best joint appearance, and strength. Martensite phase was detected in the weld area and heat affected zone (HAZ), affecting the joint mechanical properties. Hardness property varied across the welded joint, and maximum hardness was recorded at the HAZ at the stud side. Hardness increased with the increasing welding current. At 800 A, welding current hardness was 10% higher than at 400 and 600 A. Torque strength was affected by weld reinforcement, and 800 A gave the best weld reinforcement that produced the highest torque strength. Research limitations/implications The main research limitation is the difficulty of welding LAS studs and GS plates. In conventional welding methods, such as gas metal arc welding, it is hard to get full weld penetration due to the geometry restrictions of the joint, which results in partial weld penetration between the studs and the plates. Furthermore, the issue of zinc evaporation during welding can be reduced by the advantage of the very high welding speed (in milliseconds) of ASW that overcomes the problem of continuous welding that usually results in the formation of harmful porosities and poor weldability. Originality/value In this research, galvanized steel plates were successfully welded to LAS studs using the ASW process. The welding parameters for this dissimilar welding joint were carefully selected. Microstructure changing due to the welding process was investigated. The joint mechanical properties were evaluated.

2

Butt welding of thin sheets of S960MC steel

Mičian Miloš, Frátrik Martin, Trško Libor, Gucwa Marek, Winczek Jerzy, Skroński Łukasz

Welding Technology Review

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2021

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R. 93, nr 2

5--12

EN

The paper presents the application of MAG welding to TMCP steels (thermo-mechanically controlled processed) grade S960MC and 3 mm thick. In the analyzed joints, the research focused on their mechanical properties and changes in the heat-affected zone (HAZ) that occur in this type of steels. The hardness and tensile strength tests carried out showed a significant decrease in the properties of the joint compared to the declared values of the base material and the filler material used in the tests. In the case of hardness, it was a decrease of 34% in HAZ and by 15-21% in relation to the strength limit. Changes in HAZ properties of a joint correlate with changes in its structure.

PL

W artykule przedstawiono zastosowanie spawania metodą MAG do stali z grupy TMCP (walcowanych termomechanicznie) o oznaczeniu S960MC i grubości 3 mm. W analizowanych złączach skupiono się na badaniach ich właściwości mechanicznych oraz zmian w strefie wpływu ciepła (SWC) jakie zachodzą w tego typu stalach. Przeprowadzone badania twardości i wytrzymałości na rozciąganie wykazały znaczny spadek właściwości w złączu w porównaniu z deklarowanymi wartościami materiału podstawowego oraz dodatkowym jakie zostały użyte w badaniach. W przypadku twardości był to spadek o 34% w SWC oraz o 15-21% w odniesieniu do granicy wytrzymałości. Zmiany właściwości w SWC złącza korelują ze zmianami zachodzącymi w jego strukturze.

3

Hard from edge to edge : innowacyjna metoda poprawy żywotności części roboczych maszyn i urządzeń

Fedoryszyn Tomasz, Sobieraj Marek

Surowce i Maszyny Budowlane

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2021

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nr 4

44--48

PL

W artykule przedstawiono, w oparciu o badania własne zlecone zewnętrznym jednostkom naukowym, wpływ strefy wpływu ciepła oraz zastosowanie technologii Miilux "Hard from Edge to Edge" jako realnej i skutecznej metody wydłużenia żywotności produkowanych elementów i części maszyn. Poprzez odwrócenie procesu technologicznego i w efekcie całkowitą eliminację strefy wpływu ciepła, osiągnięto jednolite parametry twardości, a w efekcie wydłużenie trwałości produkowanych elementów.

4

Microstructure, toughness and hardness of a simulated HAZ in steel S1100QL and of the HAZ of an actual MAG-welded joint made using a metallic flux-cored wire

Łomozik Mirosław

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2021

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Vol. 65, No. 5

47--65

EN

Simulation tests discussed in the article involved structural steel S1100QL having a yield point of more than 900 MPa. The simulations included single (Tmax = 1250°C) and double welding thermal cycle (Tmax = 1250°C + 600°C, Tmax = 1250°C + 760°C and Tmax = 1250°C + 900°C) as well as cooling times t8/5 = 3, 5 and 10 s. Specimens with the simulated heat affected zone (HAZ) were subjected to impact strength tests performed at a temperature of -40°C and +20°C, Vickers hardness tests (HV10) and microscopic metallographic tests (involving light microscopy). Test results were presented in diagrams and photographs. Related comparisons included results of the structural, hardness and toughness tests of simulated HAZs with analogous results obtained during the actual repair welding of a MAG-welded joint made of steel S1100QL. The final part of the article contains discussion concerning the test results and the statement concerning the obtainment of the significant conformity of the phase composition and the morphology of the microstructure as well as the average hardness values of the HAZ areas obtained in the simulations and those of the HAZ area obtained in the actual welded joint. In relation to all tested simulation variants, the impact energy of the simulated HAZ area of steel S1100QL satisfied the minimum criterion of KV = 27 J both in relation to a test temperature of -40°C and that of +20°C. The number of repeated (1 through 4) thermal cycles having preset parameters did not trigger explicitly noticeable changes in impact energy values as regards the simulated HAZ of steel S1100QL.

PL

Przedmiotem badań symulacyjnych opisanych w artykule była stal konstrukcyjna o granicy plastyczności powyżej 900 MPa typu S1100QL. Zostały przeprowadzone symulacje dla pojedynczego (Tmax= 1250°C) i podwójnego cyklu cieplnego spawania (Tmax= 1250°C + 600°C, Tmax 1250°C + 760°C oraz Tmax= 1250°C + 900°C), dla czasów chłodzenia t8/5= 3, 5 i 10 s. Próbki z zasymulowanymi obszarami SWC poddano badaniom udarności w temperaturach -40°C oraz +20°C, pomiarom twardości sposobem Vickersa HV10 oraz badaniom metalograficznym mikroskopowym przy użyciu mikroskopii świetlnej. Wyniki badań zestawiono na wykresach i na zdjęciach fotograficznych. Porównano uzyskane wyniki badań: strukturalnych, twardości oraz udarności symulowanych obszarów SWC z analogicznymi wynikami badań rzeczywistego naprawczego złącza spawanego stali S1100QL, wykonanego metodą MAG. Na zakończenie omówiono wyniki badań i stwierdzono m.in. że uzyskano dużą zgodność składu fazowego i morfologii mikrostruktury oraz średnich wartości twardości obszarów SWC otrzymanych w wyniku symulacji i obszaru SWC w naprawczym złączu spawanym. Ponadto praca łamania symulowanego obszaru SWC stali S1100QL, dla wszystkich badanych wariantów symulacji, spełniała kryterium minimalnego KV = 27 J zarówno przy temperaturze badania -40°C, jak i +20°C. Krotność powtórzeń cyklu cieplnego o zadanych parametrach w zakresie od jednokrotnego do czterokrotnego nagrzewania nie powodowała jednoznacznej tendencji zmian wartości pracy łamania symulowanych obszarów SWC stali S1100QL.

5

Analysis of selected properties of induction welded seamed tubes

Techmański Zbigniew, Stępień Mariusz, Stępień Jacek

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2021

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Vol. 65, No. 5

31--36

EN

The article discusses research work concerning an innovative welding technology enabling the continuous joining of steel tubes using the high-frequency induction heating process. The article focuses primarily on issues related to weld formation, particularly as regards the formation of the heat affected zone (HAZ), enabling the obtainment of the proper angle of a material flow line (referred to as the upsetting line), appropriate proportions of the HAZ and the ferritic line. The proper performance of the technological process enables the obtainment of a high-quality joint (tube seam) superior to that obtained using previous solutions and satisfying safety-related requirements concerning pipelines used in the transport of liquids and gases characterised by low operating pressure. The results presented in the article were obtained in metallographic tests of the joints. The test results revealed the obtainment of joints characterised by required quality.

PL

Artykuł poświęcony jest pracom nad innowacyjną technologią zgrzewania rur stalowych w sposób ciągły w procesie nagrzewania indukcyjnego wysokiej częstotliwości. Artykuł, w główniej mierze, odnosi się do zagadnień związanych z procesem powstawania zgrzeiny, a w szczególności do sposobu kształtowania strefy wpływu ciepła SWC pozwalającego na uzyskanie właściwego kąta linii płynięcia materiału – tzw. linii spęczania – właściwych proporcji SWC i linii ferrytycznej. Przeprowadzenie procesu technologiczno-technicznego we właściwy sposób pozwala na uzyskanie wysokiej jakości połączenia (szwu rury) przewyższającego dotychczasowe rozwiązania i tym samym spełniającego wymogi bezpieczeństwa dla rurociągów transportowych cieczy i gazów o niskich ciśnieniach roboczych. Zamieszczone w artykule wyniki odnoszą się do badań metalograficznych wykonanych na połączeniach testowych. Badania te wykazały uzyskanie oczekiwanych właściwości połączeń.

6

Microstructural evaluation of the high-frequency induction welded joints of low carbon steel pipes

Bunsch Adam, Krawczyk Janusz, Matusiewicz Piotr

Advances in Materials Science

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2021

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Vol. 21, nr 4(70)

19--33

EN

The work presents the results of research on the structure of welded joints in the area of heat affected zone (HAZ). Based on precisely performed metallographic tests, the contribution of individual structural components in the area of welds of pipes welded with the induction method was assessed. The volume fraction of individual structural components in various areas of the heat affected zone, the size of the grain formed in the welding process, as well as its shape coefficients were determined. On the basis of metallographic observations, an attempt was made to describe the course of the pressure induction welding process, taking into account the structural changes, phase changes and the recovering and recrystallization processes taking place in this process.

7

Analiza warunków technologicznych wytwarzania matryc kuziennych

Figna Anna, Figna-Zientz Ewa, Góral Jan, Górecki Artur, Rozpondek Maciej

Hutnik, Wiadomości Hutnicze

|

2020

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Vol. 87, nr 11-12

264--267

PL

Przedstawiono parametry procesu technologicznego wytwarzania matryc kuziennych. Przeanalizowano wpływ czynników oddziaływujących bezpośrednio na trwałość matryc. Scharakteryzowano kryteria doboru materiałów na podłoże matrycy (rdzeń) i napoinę w aspekcie dostępności rynkowej w celu wykonania badań weryfikujących ich parametry technologiczne. W oparciu o teorię podobieństwa określono wartości strumieni cieplnych zapewniających stabilizację temperatury matrycy podczas procesu napawania.

EN

Parameters of the technological process of manufacturing forging closed - dies are presented. The influence of factors directly affecting the durability of the closed - dies was analyzed. The criteria for the selection of materials for the closed - dies substrate (core) and the padding weld were characterized in terms of market availability, in order to perform tests verifying their technological parameters. Based on the theory of similarity, the values of thermal fluxes ensuring the stabilization of the closed - dies temperature during the padding process were determined.

8

Heat affected zone analysis of Ti6Al4V after WEDM

Poroś Dariusz, Zaborski Stanisław, Karolczak Paweł

Mechanik

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2019

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R. 92, nr 12

833--835

EN

Perspectives of applications WEDM for cutting titanium alloys are presented. There is space to explore how application of proper time parameters and the material of wire electrode for WEDM of titanium alloys affects the surface roughness, structure, the stress and the chemical composition of the formed surface layer.

PL

Przedstawiono problematykę obróbki elektroerozyjnej tytanu z uwzględnieniem doboru parametrów czasowych oraz materiału elektrody drutowej. Podjęto także temat analizy geometrii obrobionej powierzchni i strefy wpływu ciepła.

9

Laser treatment with 625 Inconel powder of hot work tool steel using fibre laser YLS-4000

Dobrzański L. A., Jonda E., Pakieła W., Dziekońska M.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 91, nr 2

60--67

EN

Purpose: The purpose of this investigation was to determine the changes in the surface layer (Inconel 625), obtained during the laser treatment of tool-steel alloy for hot work by the use high-power fibre laser. Design/methodology/approach: Observations of the layer structure, HAZ, and substrate material were made using light and scanning microscopy. The composition of elements and a detailed analysis of the chemical composition in micro-areas was made using the EDS X-ray detector. The thickness of the resulting welds, heat affected zone (HAZ) and the contribution of the base material in the layers was determined. Findings: As a result of laser cladding, using Inconel 625 powder, in the weld overlay microstructure characteristic zones are formed: at the penetration boundary, in the middle of weld overlay and in its top layer. It was found that the height of weld overlay, depth of penetration, width of weld overlay and depth of the heat affected zone grows together with the increasing laser power. Practical implications: Laser cladding is one of the most modern repair processes for eliminating losses, voids, porosity, and cracks on the surface of various metals, including tool alloys for hot work. Laser techniques allow to make layers of materials on the repaired surface, that can significantly differ in chemical composition from the based material (substrate material) or are the same. Originality/value: A significant, dynamic development in materials engineering as well as welding technologies provides the possibility to reduce the cost of production and operation of machinery and equipment, among others by designing parts from materials with special properties (both mechanical and tribological) and the possibility of regeneration of each consumed element with one of the selected welding technologies.

10

About weldability and welding of Al alloys: case study and problem solving

Fracchia E., Gobber F., Rosso M.

Journal of Achievements in Materials and Manufacturing Engineering

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2017

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Vol. 85, nr 2

67--74

EN

Purpose: Among many disciplines within engineering, welding is probably one of the most inexact – rather more of an art than a science. As weldment is meant the complete joint comprising the weld metal, heat affected zones (HAZ) and the adjacent parent metal and should have the same properties as the parent metal. This paper aims provides a basic understanding of the metallurgical principles involved in how aluminium alloys achieve their strength and how welding can affect these properties. The most important and applied welding processes to Al alloys are here shortly introduced, as well as the preparation of parent metals prior to welding and good welding practice to avoid and/or keep under control defects and failures. Some case studies with possible failures will be introduced together with actions and suggestions to solve the observed problems. Design/methodology/approach: Two sheets of the EN AW 5454 (AlMg3Mn) alloy were weld with resistance welding process and after a mechanical processing of lamination was observed the presence of the defect. The microstructure of the defect as well as the welded part were evaluated with stereomicroscope (LEICA MS5), optical microscope (LEICA MEF4M), and with SEM analysis (LEO 1540 VP equipped with an energy dispersive X-ray spectroscope Oxford Link Pentafet). Findings: The well welded part was analysed with optical microscopy and electronic microscopy resulting with the attended mechanical properties. Micro-hardness indentations on the joint demonstrated the good mechanical properties of the joint while with the microscopic observations were identified the orientation and presence of precipitates typical of this alloy. In the defect, microscopically observations showed the presence of oxide inclusions. Research limitations/implications: There are a number of problems associated with the welding of aluminium and its alloys that make it difficult to achieve this ideal. The features and defects that may contribute to the loss of properties comprise the following: gas porosity, oxide inclusions and oxide filming, solidification (hot) cracking or hot tearing, reduced strength in the weld and HAZ, lack of fusion, reduced corrosion resistance and reduced electrical resistance. Originality/value: This case study illustrated clearly the importance of the cleaning on the surfaces to obtain a well welded joint ensuring the desired mechanical properties.

11

Fatigue crack growth resistance of welded joints simulating the weld-repaired railway wheels metal

Ostash O. P., Kulyk V. V., Poznyakov V. D., Haivorons’kyi O. A., Markashova L. I., Vira V. V., Duriagina Z. A., Tepla T. L.

Archives of Materials Science and Engineering

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2017

|

Vol. 86, nr 2

49--55

EN

Purpose: The aim of the paper is to study the structure and fatigue crack growth resistance characteristics of weld metal (WM), and heat affected zone (HAZ) under cyclic loadings for the development of railway wheels weld-repairing technology. Design/methodology/approach: WM and HAZ of the welded joint were investigated. The welded joint of 65G steel (0.65 mass.% C; 0.19 Si; 0,91 Mn), which is a model material for high-strength railway wheels, was received by welding Sv-08HM wire per linear welding energy of 10 kJ/cm. Regimes of welding were selected so that the cooling rate of the metal in the temperature range 500-600°C was 5°C/s. As a result, the bainite structure in WM and bainite-martensite one in HAZ are formed. To eliminate the residual stresses generated after the weld cooling, heat treatment was proposed: holding at 100°C for 2 hour after cooling under temperature below then that at the beginning of martensite transformation. Fracture resistance under cyclic loading was estimated by fatigue crack growth rates diagrams (da/dN vs. ΔK) according to standard method for compact tension samples testing. The microstructure and fracture surface were investigated using an optical, and electronic scanning and transmission microscope. Findings: Microstructure parameters and fatigue crack growth resistance characteristics of WM and HAZ after the proposed heat treatment, and also residual stresses of the second kind and local strains in the bulk of bainite and martensite are obtained. Research limitations/implications: Investigations were conducted on samples that simulate the structure and properties of real renovated railway wheels made of steel with high content (0.65%) of carbon. Practical implications: Service durability and safety of weld-repaired railway wheels under high service loadings is increased. Originality/value: HAZ is the most dangerous zone in terms of fatigue cracks initiation and propagation in elements repaired by surfacing method. The positive result on the proposed heat treatment influence is received since the fatigue crack growth resistance characteristics of HAZ metal with bainite-martensite structure raise to the level of weld metal.

12

The Influence of Different Assist Gases on Ductile Cast Iron Cutting by CO2 Laser

Meško J., Nigrovič R., Zrak A.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

109--114

EN

This article deals with the technology and principles of the laser cutting of ductile cast iron. The properties of the CO2 laser beam, input parameters of the laser cutting, assist gases, the interaction of cut material and the stability of cutting process are described. The commonly used material (nodular cast iron - share of about 25% of all castings on the market) and the method of the laser cutting of that material, including the technological parameters that influence the cutting edge, are characterized. Next, the application and use of this method in mechanical engineering practice is described, focusing on fixing and renovation of mechanical components such as removing the inflow gate from castings with the desired quality of the cut, without the further using of the chip machining technology. Experimental samples from the nodular cast iron were created by using different technological parameters of laser cutting. The heat affected zone (HAZ), its width, microstructure and roughness parameter Pt was monitored on the experimental samples (of thickness t = 13 mm). The technological parameters that were varied during the experiments included the type of assist gases (N2 and O2), to be more specific the ratio of gases, and the cutting speed, which ranged from 1.6 m/min to 0.32 m/min. Both parameters were changed until the desired properties were achieved.

13

Wpływ parametrów cięcia laserowego na jakość powierzchni cięcia. Cz. 1

Mazurkiewicz A.

Stal, Metale & Nowe Technologie

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2016

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nr 9-10

112--118

PL

W artykule określono podstawowe parametry wpływające na jakość powierzchni cięcia laserowego. Zwrócono uwagę na wpływ cię- cia laserowego na zmiany w warstwie wierzchniej oraz dokładność wycinanego kształtu, a w tym m.in. na: znaczenia ogniska wiązki laserowej, chropowatość powierzchni cięcia, prostopadłość powierzchni bocznej, wielkość szczeliny cięcia. Porównano właściwości technologiczne cięcia różnych gatunków materiałów o różnej grubości: stali węglowej, stali wysokostopowej i stopu aluminium.

EN

The article set out basic parameters affecting the surface quality of laser cutting. Special attention is paid to the impact of laser cutting on the changes in the surface layer and the accuracy of shape, including, inter alia, the importance of the laser focus, surface roughness, perpendicularity of the surface and the size of the cutting kerf. The technological properties of the cutting of various types of materials of different thicknesses, such as: carbon steel, high-alloy steel, and an aluminum alloy, have been compared.

14

Wpływ parametrów cięcia laserowego na jakość powierzchni cięcia. Cz. 2

Mazurkiewicz A.

Stal, Metale & Nowe Technologie

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2016

|

nr 11-12

25--30

PL

W artykule określono podstawowe parametry wpływające na jakość powierzchni cięcia laserowego. Zwrócono uwagę na wpływ cię- cia laserowego na zmiany w warstwie wierzchniej oraz dokładność wycinanego kształtu, a w tym m.in. na: znaczenia ogniska wiązki laserowej, chropowatość powierzchni cięcia, prostopadłość powierzchni bocznej, wielkość szczeliny cięcia. Porównano właściwości technologiczne cięcia różnych gatunków materiałów o różnej grubości: stali węglowej, stali wysokostopowej i stopu aluminium.

EN

The article set out basic parameters affecting the surface quality of laser cutting. Special attention is paid to the impact of laser cutting on the changes in the surface layer and the accuracy of shape, including, inter alia, the importance of the laser focus, surface roughness, perpendicularity of the surface and the size of the cutting kerf. The technological properties of the cutting of various types of materials of different thicknesses, such as: carbon steel, high-alloy steel, and an aluminum alloy, have been compared.

15

Wymiar fraktalny wybranych struktur złączy spawanych ze stali 15HM

Grześ J.

Przegląd Spawalnictwa

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2016

|

R. 88, nr 6

38--44

PL

Przedmiotem przedstawionych badań były struktury złącza spawanego ze stali 15HM. Głównym celem badań było określenie wymiaru fraktalnego wybranych struktur spoiny i strefy wpływu ciepła. W tym celu zastosowano cyfrowe przetwarzanie i analizę obrazu. Dla badanych struktur określono wymiar fraktalny pudełkowy i liniowy, wykorzystując odpowiednio metodę ”Box Counting Dimension” (BCD) oraz jej modyfikację „Line Counting Dimension” (LCD).

EN

The paper presents the results of fractal dimension measurements. The selected cross-sections structures of 15HM steel welded joint have been the subject of investigations. The computer image processing techniques have been applied to prepare images of structures for measurements. Both box (BCD) and line (LCD) counting dimension algorithms have been used to obtain the fractal dimension of analyzed structures.

16

Spawanie metodą CMT (Cold Metal Transfer) w porównaniu z klasyczną metodą MAG w przemyśle motoryzacyjnym

Mirski Z., Pękala P.

Przegląd Spawalnictwa

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2016

|

R. 88, nr 2

15--20

PL

Obecnie jednym z wielu kierunków rozwoju zrobotyzowanych metod spawania jest łączenie cienkich blach z materiałów o jednakowych i różnorodnych właściwościach. Potrzeby przemysłu i łatwość zrobotyzowania metody MIG/MAG doprowadziły do szybkiego wdrożenia metody Cold Metal Transfer (CMT). W artykule przedstawiono analizę metody CMT w odniesieniu do klasycznej metody MAG na przykładzie zrobotyzowanego spawania w przemyśle motoryzacyjnym. Do wykonania złączy próbnych zastosowano blachy ze stali S355MC o grubości 3 mm, które stanowią elementy składowe spawanej konstrukcji oparcia fotela samochodowego. Wykonane połączenia próbne, przy zróżnicowanej energii liniowej spawania, poddano badaniom makrostrukturalnym oraz pomiarom twardości. Wyniki pomiarów obrazują wpływ energii liniowej spawania oraz prędkości podawania spoiwa na geometrię spoin i szerokość strefy wpływu ciepła [1].

EN

Nowadays combining thin steel sheet with the same and different materials properties is one of the main routes robotized of welding. The needs of industry and ease of robotized MIG/MAG led to the rapid implementation Cold Metal Transfer method (CMT). The article presented the analysis CMT method in comparison to classical method of MAG based on robotized welding in the automotive industry. Welded test joints are made of sheet steel S355MC thickness of 3 mm, this material is used as a component for car seats. Welding connections were investigated in macrostructure test and hardness with differentiated the Welding Energy Input. The measurement results reflect the impact of Welding Energy Input and wire-feed speed on the geometry of the welds and heat affected zone width [1].

17

The influence of the heat source model selection on mapping of heat affected zones during surfacing by welding

Winczek J.

Journal of Applied Mathematics and Computational Mechanics

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2016

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Vol. 15, nr 3

167--178

EN

The paper compares forms and dimensions of heat affected zones determined on the basis of analytical descriptions of temperature fields caused by different models of heat source. In the first case, a single-distributed volumetric heat source model reflecting only the impact of an electric arc was assumed. In further considerations, bimodal heat source models were applied. The first one consists of a volumetric heat source model of weld reinforcement (of melted electrode material) and a surface model of an electric arc. In the second one a bimodal source is the sum of volumetric heat source models of weld reinforcement and an electric arc. Calculations are based on the example of submerged arc welding of a rectangular S355 steel element. The results of numerical simulations were verified experimentally, confirming the argument that it is necessary to include the bimodal heat source in temperature field modelling, which takes into account the temperature rises caused by the heat of melted electrode material.

18

Influence of the welding process on martensitic high strength steel

Hanus P., Konecny M.

Production Engineering Archives

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2014

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Vol. 3, No. 2

31--34

EN

The subject of the study is martensitic 22MnB5 steels, which are used in the automotive industry. The main purpose of the performed analyses is a study of strength differences in heat affected zones of the spot welding. For the needs of the strength decrease assessment, the critical layer of the heat affected area was experimentally simulated. The aim of the work is to determine the most suitable methodology for evaluating the local changes of the elastic-plastic material response. The aim of this work is to determine the optimal methods for the determination of the yield strength and to find a firming trend in these zones.

19

Modelowanie strefy wpływu ciepła podczas jednościegowego napawania z wykorzystaniem dwurozkładowego modelu źródła ciepła

Winczek J.

Modelowanie Inżynierskie

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2014

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T. 19, nr 50

69--76

PL

Przyjmowane w opisach pola temperatury podczas napawania jednorozkładowe modele źródła nie pozwalają na odtworzenia nieregularnych kształtów izoterm (w tym linii wtopienia), dlatego też zaproponowano model dwurozkładowy, znajdując uzasadnienie w sposobie przekazywania do napawanego przedmiotu ciepła wydzielonego przez łuk elektryczny. Wykonano obliczenia pola temperatury dla przykładu jednościegowego napawania płyty ze stali S235. Uzyskano potwierdzenie wymiarów i kształtu linii wtopienia uzyskanej doświadczalnie przez innych badaczy, używając w obliczeniach parametrów napawania przyjętych w eksperymencie. Wartości maksymalnej temperatury umożliwiły wyznaczenie charakterystycznych stref wpływu ciepła. Obliczono udziały objętościowe poszczególnych składników strukturalnych (ferrytu, perlitu i bainitu).

EN

Single-distributed heat source models accepted in the descriptions of the temperature field during surfacing by welding, do not allow for restoration of irregular isotherms shapes (including the fusion line), therefore a bimodal model is proposed, finding justification in the way of transmitting heat generated by an electric arc to the surfaced object. Calculations of the temperature field were performed for a single-pass surfaced S235 steel plate. The size and shape of the fusion line, experimentally obtained by other investigators, was confirmed, using in the calculations the welding parameters adopted in the experiment. The maximum temperature allowed for the determination of specific heat affected zones. The volume fractions of particular structural components (ferrite, pearlite and bainite) were calculated.

20

CrMoV steel welding in the narrow gap using of SAW technology

Holub L., Dunovský J., Suchánek J.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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Vol. 62, nr 1

31--37

EN

Purpose: of this paper is the verification of multi-layer SAW welding the raw material “1.6946” by different welding consumables (TOPCORE 838 B, Thermatit MTS 616) in the „ultra” narrow gap using the prescribed temperature cycle and subsequent heat treatment. Design/methodology/approach: An evaluation of the mechanical properties of the test for both types welding consumables. The measured values of yield strength and the tensile strength exhibit comparable properties to the RAW material “Inspection Certificate” for welding consumable “TOPCORE 838 B”. Findings: Thermatit MTS 616” was found falling below the specified values of impact energy, ductility. The welding consumable TOPCORE 838 B shows less susceptibility to the brittleness. Based on the results will be verified by the existence of internal structures arising using the microstructure analysis & ARA diagram of the base material 1.6496. Research limitations/implications: Obtained results will be subsequently verified the existence of internal generated microstructures using the ARA chart of the base material (W Nr. 1.6496) for the future design of the new temperature cycles in all phases of the production. Originality/value: The welding consumable “TOPCORE 838 B” showed the low tendency to embrittlement in the heat-affected zone using the defined heat treatment. On the basic of the examination the welding consumable “TOPCORE 838 B” can be recommended to be used for the welding process, thermal cycle and heat treatment.