Temat: HAZ - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Effect of Grit Blasting and Thermal Spraying on Microstructure Evolution of P91 Weldment
Autorzy:: Thakare, J. G.
Pandey, C.
Mulik, R. S.
Mahapatra, M. M.
Narang, H. K.
Tematy:: P91
HAZ
IC-HAZ
deformation zone; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/947576.pdf Link otwiera się w nowym oknie
Opis:: In the present work, studies have been carried out on the variations in the microstructure and hardness of P91 base-metal and welded joint. This variations result from the grit blasting and thermal cycle experienced during the thermal spraying process. The microstructural effects have been analyzed in terms of the depth of the deformation zone. Scanning Electron Microscopy and Xray diffraction were used as characterization techniques. The grit blasting carried out prior to thermal spraying has resulted in the highest change in sub-surface hardness of the heat affected zone (HAZ). However, flame treatment further reduced the subsurface hardness of the heat affected zone. The depth of deformation zone was highest for inter-critical heat affected zone (IC-HAZ). The overall coating process resulted in an increase in subsurface hardness of various regions of HAZ and fusion zone (FZ). The base metal showed a 7% increase in subsurface hardness due to the overall coating process. The IC-HAZ showed maximum variation with 36% increase in subsurface hardness. The coarse grained heat affected zone (CG-HAZ) and FZ did not show any change in subsurface hardness. As a whole, the hardness and microstructure of the welded joint was observed to be more sensitive to the thermal spray coating process as compared to the base metal.
Dostawca treści:: Biblioteka Nauki

Artykuł

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Skocz do pozycji: 2.

Tytuł:: Investigations of polypropylene foil cutting process using fiber Nb: YAG and Diode Nd:YVO4 lasers
Autorzy:: Kukiełka, Leon
Patyk, Radosław
Bohdal, Łukasz
Napadłek, Wojciech
Gryglicki, Rafał
Kasprzak, Piotr
Tematy:: laser
cutting
polypropylene foil
HAZ; Pokaż więcej
Wydawca:: Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Powiązania:: https://bibliotekanauki.pl/articles/387021.pdf Link otwiera się w nowym oknie
Opis:: Lasers are widely used in a variety of manufacturing processes including: depaneling, drilling, cutting, repair, trimming, micromachining. Polypropylene foils are intensively investigated as materials with great number of potential applications. Laser cutting is a major operation used in forming these materials and preparing the final workpieces. At the moment, the main challenge when cutting polypropylene is to obtain high quality products characterized by optimum sheared edge condition, minimum surface damage, freedom from burrs, slivers, edge wave, distortion, residual stresses and to obtain minimum width of HAZ zone. The amount of adjusTab. process parameters and the fact that the influence of these parameters on the process is not fully understood makes it difficult to control the cutting process. In practice, the right setup for the lasers is mostly found by trial and error combined with experience. Therefore, the final product frequently has serious defects. The paper presents the possibility of using fiber and diode lasers for forming of workpieces from polypropylene multilayer foil using cutting technology. The effect of selected process parameters and conditions on quality of sheared edge and material degradation is discussed.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Determination of Ranges of Components of Heat Affected Zone Including Changes of Structure
Określenie zakresów składowych strefy wpływu ciepła uwzględniając zmiany struktury
Autorzy:: Śloderbach, Z.
Pająk, J.
Tematy:: welding
heat-affected zone
weld
length of components of HAZ
pipelines
spawanie
strefy wpływu ciepła
spoina
HAZ
rurociągi; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/353514.pdf Link otwiera się w nowym oknie
Opis:: A simplified analytical method to determine the range of the heat affected zone and its components during welding is presented. Heat affected zone (HAZ) is an area formed during welding in which, as the result of temperature, some structural changes in the welded material occured. Knowledge of the area and sub-areas of HA Z is important from practical point of view, since the area of the fine-grained HAZ is a critical place in terms of creep strength and thermal fatigue. Heat affected zone is often the cause of future damage of many devices in which welding technology was used for their repair.
Przedstawiono uproszczoną analityczną metodę służącą do określenia zakresu wpływu strefy ciepła i zakresów jej stref składowych podczas spawania. Obszar (strefa) wpływu ciepła (HA Z) to obszar, w którym podczas procesu spawania w wyniku działania wysokiej temperatury zaszły strukturalne zmiany w spawanym materiale. Wiedza na temat obszaru i podobszarów HA Z jest ważna z praktycznego punktu widzenia, ponieważ np. strefa drobno-ziarnistego HA Z jest krytycznym obszarem wytrzymałości na pełzanie oraz zmęczenia cieplnego. HA Z (strefa wpływu ciepła) jest często miejscem i przyczyną późniejszego uszkodzenia wielu urządzeń, które naprawiano techniką spawania.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Weldability of Thermomechanically Treated Steels Having a High Yield Point
Spawalność stali obrabianej termomechanicznie o wysokiej granicy plastyczności
Autorzy:: Górka, J.
Tematy:: weldability
TMCP steel
HAZ
spawalność
stal TMCP; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/353588.pdf Link otwiera się w nowym oknie
Opis:: The article concerns the issue of weldability of S700MC steel, treated thermo-mechanically, with high yield point. The weakest area of welded joints of this steel is a high - temperature coarse heat affected zone (HAZ) in which due to the nucleation effect of the dissolved phases, strengthening the matrix and their subsequent uncontrolled separation precipitation in the form of finely disperse and rapid decrease impact strength is observed. Performed arc welding tests here have shown that in order to ensure high quality of welded joints, it is necessary to limit the welding linear heat input. During the welding process of S700MC steel, it is not recommended to use pre heating before the welding process and heat treatment after welding, and the number of repairs should be kept to a minimum, because it leads to a reduction of strength and plastic properties in the HAZ area, as a result of aging processes, dissolution of strengthening phases in the matrix and their subsequent uncontrolled precipitation during cooling.
W pracy przedstawiono problematykę spawalności stali obrabianej termomechanicznie S700MC o wysokiej granicy plastyczności. Najsłabsze miejsce złącza spawanego tej stali stanowi wysokotemperaturowy, gruboziarnisty obszar strefy wpływu ciepła (SWC), w którym na skutek zarodkowania rozpuszczonych faz umacniających w osnowie i ich ponownego, niekontrolowanego wydzielenia w postaci drobnodyspersyjnej, następuje gwałtowny spadek udarności. Przeprowadzone próby spawania łukowego wykazały, że w celu zapewnienia wysokiej jakości złączy spawanych należy ograniczyć energię liniową spawania. Podczas spawania stali S700MC nie zaleca się stosowania podgrzewania wstępnego przed spawaniem oraz obróbki cieplnej po spawaniu, a liczbę napraw należy ograniczyć do minimum, gdyż prowadzi to do obniżenia własności wytrzymałościowych i plastycznych w obszarze SWC, na skutek procesów o charakterze starzeniowym, rozpuszczania faz umacniających w osnowie i ich ponownego, niekontrolowanego wydzielania w czasie chłodzenia.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Welding thermal cycle-triggered precipitation processes in steel S700MC subjected to the thermo-mechanical control processing
Autorzy:: Górka, J.
Tematy:: hardening phases
precipitation processes
TMCP steel
weld
HAZ; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/355934.pdf Link otwiera się w nowym oknie
Opis:: This study presents tests concerned with welding thermal process-induced precipitation processes taking place in 10 mm thick steel S700MC subjected to the Thermo-Mechanical Control Process (TMCP) with accelerated cooling. The thermomechanical processing of steel S700MC leads to its refinement, structural defects and solutioning with hardening constituents. Tests of thin foils performed using a transmission electron microscope revealed that the hardening of steel S700MC was primarily caused by dispersive (Ti,Nb)(C,N) precipitates (being between several and less than twenty nanometers in size). In arc welding, depending on a welding method and linear energy, an increase in the base material in the weld is accompanied by the increased concentration of hardening microagents in the weld. The longer the time when the base material remains in the liquid state, the greater the amount of microagents dissolved in the matrix. During cooling, such microagents can precipitate again or remain in the solution. An increase in welding linear energy is accompanied by an increase in the content of hardening phases dissolved in the matrix and, during cooling, by their another uncontrolled precipitation in the form of numerous fine-dispersive (Ti,Nb)(C,N) precipitates of several nm in size, leading to a dislocation density increase triggered by type 2 internal stresses.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Processing of printed circuit boards using a 532 nm green laser
Autorzy:: Ciszewski, Piotr
Sochacki, Mariusz
Tematy:: laser cutting
flexible printed circuits
heat affected zone
HAZ; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/1818232.pdf Link otwiera się w nowym oknie
Opis:: The paper describes a research on assessing the quality of edges resulting from the interaction of laser pulses with a material of rigid and flexible printed circuits. A modern Nd:YVO4 crystal diode-pumped solid-state laser generating a 532 nm wavelength radiation with a nanosecond pulse time was used for the research. Influence of laser parameters such as beam power and pulse repetition frequency on a heat affected zone and carbonization was investigated. Quality and morphology of laser-cut substrates were analyzed by optical microscopy. High quality laser cutting of printed circuit board substrates was obtained without delamination and surface damage, with a minimal carbonization and heat affected zone. The developed process was implemented on the printed circuit assembly line.
Dostawca treści:: Biblioteka Nauki

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na półce

Skocz do pozycji: 7.

Tytuł:: Residual Stresses Measurement in the Weld Seam of X70 Steel, Analyzed by XRD
Autorzy:: Hamdi, M.
Benhorma, H.
Hadjaj, A.
Benchatti, A.
Tematy:: welding
residual-stresses
HAZ
steel-X70
sinψ²; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1031509.pdf Link otwiera się w nowym oknie
Opis:: Determination of residual stresses in the welded areas of metal structures is a very important operation in the mechanical construction and other fields, for the reliability and sustainability of these metal structures [J.B. Ju, S.K. Lee, J. Jang, W.S. Kim, D. Kwon, Int. J. Press. Vessels Piping 80, 641 (2003)]. Over the past few years, a significant number of studies have been carried out in order to understand the influence of residual stresses on the assembly by welding, from the standpoint of mechanical properties and corrosion resistance [E. Macherauch, K.H. Kloos, Residual Stresses in Science and Technology, DGM Inform. Verlag, 1987, p. 3; P.J. Withers, H.K.D.H. Bhadeshia, Master Sci. Technol. 17, 366 (2001)]. Several studies have been carried out for the purpose of finding non-destructive methods for the evaluation of the residual stress [H. Nasri, Mesure De Contraintes Résiduelles Dues Au Soudage Et Au Soudage-Martelage Par Micro-Profil De Surface, Ecole De Technologie Supérieure Université Du Québec, 2007; C. Balasingh, A.K. Singh, Metals Materials Proc. 12, 269 (2000)]. One of the methods that proved important, it is that of sinψ². In this work we have applied this method in the assessment of the residual stress in the welded X70 steel.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Processing of printed circuit boards using a 532 nm green laser
Autorzy:: Ciszewski, Piotr
Sochacki, Mariusz
Tematy:: laser cutting
flexible printed circuits
heat affected zone
HAZ; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Elektryków Polskich
Powiązania:: https://bibliotekanauki.pl/articles/1818234.pdf Link otwiera się w nowym oknie
Opis:: The paper describes a research on assessing the quality of edges resulting from the interaction of laser pulses with a material of rigid and flexible printed circuits. A modern Nd:YVO4 crystal diode-pumped solid-state laser generating a 532 nm wavelength radiation with a nanosecond pulse time was used for the research. Influence of laser parameters such as beam power and pulse repetition frequency on a heat affected zone and carbonization was investigated. Quality and morphology of laser-cut substrates were analyzed by optical microscopy. High quality laser cutting of printed circuit board substrates was obtained without delamination and surface damage, with a minimal carbonization and heat affected zone. The developed process was implemented on the printed circuit assembly line.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: The influence of manual metal arc multiple repair welding of long operated waterwall on the structure and hardness of the heat affected zone of welded joints
Autorzy:: Pikuła, J.
Łomozik, M.
Pfeifer, T.
Tematy:: repair welding
waterwall
manual metal arc welding
power engineering
HAZ; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/353851.pdf Link otwiera się w nowym oknie
Opis:: Welded installations failures of power plants, which are often result from a high degree of wear, requires suitable repairs. In the case of cracks formed in the weld bead of waterwall, weld bead is removed and new welded joint is prepared. However, it is associated with consecutive thermal cycles, which affect properties of heat affected zone of welded joint. This study presents the influence of multiple manual metal arc welding associated with repair activities of long operated waterwall of boiler steel on properties of repair welded joints. The work contains the results of macro and microscopic metallographic examination as well as the results of hardness measurements.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Pulse frequency density modulation full bridge for induction preheating application of stainless-steel welding
Autorzy:: Chakkuchan, P.
Chudjuarjeen, S.
Phankong, N.
Tematy:: stainless steel
arc welding
induction heating (IH)
heat-affected zone (HAZ)
power electronics
inverter voltage-source
stal nierdzewna
spawanie łukowe
nagrzewanie indukcyjne (IH)
strefa wpływu ciepła (HAZ)
elektronika mocy
falownik źródła napięcia; Pokaż więcej
Wydawca:: Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Powiązania:: https://bibliotekanauki.pl/articles/59116111.pdf Link otwiera się w nowym oknie
Opis:: Purpose: The paper shows the problem of surface cracks from welding (TIG welding) to welding stainless steel pipe (heat-affected zone: HAZ). The study is an experiment of preparing welding with non-heating workpieces and preheating the workpiece using the principle of induction, heating with a fluid inverter circuit that can adjust power by frequency control, pulse frequency density modulation (PFDM) to maintain temperature for industrial. Design/methodology/approach: The control circuit is responsible for regulating the functioning of different devices and the speed of operation of the switch device. It divides the control into two closed loops: phase-angle feedback and current feedback. The phase-angle feedback loop ensures frequency tracking during the phase check angle, enabling the inverter to operate at frequencies higher than the resonant frequency throughout its operation. The process of arc welding was employed in the fusion of stainless-steel materials. Preheating is a crucial step in the welding process, as it serves to uphold the integrity of the weld and mitigate the occurrence of undesirable outcomes such as cracking and the subsequent requirement for rework. The Welding Process Specification (WPS) about the task at hand will delineate the lower and upper limits of preheating temperatures and the requisite period for preheating. High-quality products should be devoid of these imperfections and possess comprehensive welding reinforcement. Additional welding certifications encompassed a tensile testing procedure, a microhardness testing procedure, and a comprehensive microstructure analysis. Findings: Applying an alternating voltage to an induction coil generates an alternating current (AC) within the coil circuit. The induced currents exhibit a frequency identical to that of the coil current, although they possess an opposite direction to the coil current. These currents facilitate heat generation through the phenomenon known as the Joule effect. The temperature range of 250°C-400°C can be effectively regulated for preheating stainless steel by using high-frequency electric process heating in induction welding, hence achieving the desired welding preheat. There are two primary classifications for inverters: voltage-source inverters and current-source inverters. Research limitations/implications: The main research limitation is comparing preheat and non-preheat. The size of the heat-affected zones is influenced by the rate of heating and cooling brought on by machining processes. By influencing the microstructural changes in that area, precise control of the variables can impact the integrity of the weld zones. The microstructural characteristics of the metal are different from the rest of the subject because welding heats the metal. The topic is heated up beforehand to ensure smooth welding and structural integrity. Because there is less of a temperature difference between the weld zone and the base material, preheating during welding results in less shrinkage stress. Distortions and crack flaws might result from higher shrinkage stress. Practical implications: NDT, or non-destructive testing, is a weld integrity test to find defects that occur in the weld without damaging that welding line and continuing to use it safely. For the welding line to be strong according to the design of that welding line (conformance to design), the test will use the principles of physical properties, such as light, X or gamma rays, magnetic fields, and high-frequency sound waves. Originality/value: In the research, stainless steel was successfully welded to preheat using induction heating (IH).
Dostawca treści:: Biblioteka Nauki

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