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EN
Effect of annealing treatment on deep drawing behavior of hot-rolled Q235 carbon steel/410/304 stainless steel three-layer composite plate was investigated. Deep drawability of the unannealed composite plates exhibits a sharp difference for various contact surfaces with the die. The limit drawing ratio (LDR) of the composite plate with the carbon steel contacting the die is 1.75, while it is 1.83 with the stainless steel contacting the die due to the different mechanical responses to the tensile stress at the corner of the die. After annealing at 900°C for 2 h, however, the deep drawabilities of the composite plates both for various contact surfaces with the die are significantly improved and becomes almost identical, which are attributed to the stress relief, the enhanced ductility and the improved interface bonding strength of the hot-rolled component plates during annealing.
PL
W artykule omówiono na podstawie literatury przemiany fazowe w azotkach żelaza wytworzonych na proszkach żelaza i na próbkach litych. Przedstawiono przemiany fazowe podczas wyżarzania w atmosferze NH3/H2 oraz w atmosferach obojętnych. Wskazano podobieństwo przemian fazowych w różnych atmosferach zastosowanych podczas wyżarzania. Opisano warunki przemian fazowych w azotkach żelaza podczas wyżarzania w atmosferze NH3/H2, w argonie oraz próżni. Przemiany fazowe zachodzące podczas wyżarzania w atmosferze NH3/H2 są odwracalne, występuje w nich zjawisko histerezy. Podczas przemiany fazowej ɛ→γ’ w atmosferze NH3/H2 do momentu zakończenia przemiany ma miejsce emisja azotu do atmosfery. Natomiast niezbędnym warunkiem przebiegu przemiany γ’→ɛ jest strumień azotu z atmosfery do powierzchni. Przemiany fazowe podczas wygrzewania w próżni i argonie są nieodwracalne. Podczas ciągłego ogrzewania azotowanych proszków żelaza z szybkością 30 K/min w próżni i argonie mogą wystąpić dwie przemiany fazowe, którym nie towarzyszy ubytek masy. Pierwsza, (α+γ’)→γN w zakresie temperatur 540÷550°C w próżni i 620÷630°C w argonie oraz druga, (γ+γ’)→ɛ w zakresie 610÷620°C w próżni i 690÷710°C w argonie. W przypadku nagrzewania w argonie początek ubytku masy rejestrowano w temperaturze ok. 860°C, natomiast w próżni kończy się w tej temperaturze odazotowanie austenitu azotowego γN. Podczas wyżarzania w temperaturze 360ºC przemianie fazowej ɛ→γ’ w warstwie ɛ/γ’ towarzyszy wzrost grubości fazy γ’, który odbywa się kosztem grubości strefy ɛ, przy czym całkowita grubość warstwy po przemianie jest taka sama, jak jej grubość w stanie wyjściowym. W temperaturze 420ºC po zakończonej przemianie ɛ→γ’, utworzona monofazowa warstwa γ’ jest grubsza od warstw ɛ/γ’ w stanie wyjściowym.
EN
In the article, based on the literature, the phase changes in iron nitrides on iron powders and on solid samples were discussed. Phase transformations in NH3/H2 atmosphere and in inert atmospheres are discussed. The similarity of phase transformations in different atmospheres used during annealing were indicated. The conditions of phase transformations in iron nitrides during annealing in NH3/H2 atmosphere, argon and vacuum were discussed. Phase transformations occurring during annealing in the NH3/H2 atmosphere are reversible and there is a hysteresis phenomenon. During the phase transformation ɛ→γ' in the NH3/H2 atmosphere until the transformation is completed, nitrogen emission to the atmosphere takes place. On the other hand, the condition for the course of the transformation of γ'→ɛ is the nitrogen flow from the atmosphere to the surface. Phase changes during heating in vacuum and argon are irreversible. During continuous heating at a rate of 30 K / min in vacuum and argon, nitrided iron powders, two phase transformations may occur, which are not accompanied by weight loss, the first (α+γ') →γN in the temperature range 540÷550°C in a vacuum and 620÷630°C in argon and the second (γ+γ') →ɛ in the range of 610÷620°C in vacuum and 690÷710°C in argon. In the case of heating in argon, the onset of weight loss was recorded at a temperature of about 860°C. Whereas in vacuum the denitration of nitrogen austenite γN ends at this temperature. During annealing at the temperature of 360°C, the phase change ɛ→γ′ in the ɛ/γ′ layer is accompanied by an increase in the thickness of the γ′ phase, which is at the expense of the thickness of the ɛ zone, while the total thickness of the layer after the transformation is the same as its initial thickness. At the temperature of 420°C, after the completion of the γ′ transformation, the formed monophasic layer γ′ is thicker than the ɛ/γ′ layers in the initial state.
EN
Bioceramic materials, such as hydroxyapatite (HAp), are characterized by high biocompatibility in the presence of tissues and body fluids without causing toxic or allergic reactions. Hydroxyapatite, due to its similarity to structures found in bones, is used both in the form of powders, e.g. as additives to bone cements, and implants coatings. However, this material is not characterized by antimicrobial properties, therefore attempts are made to improve its properties by introducing additional elements into the hydroxyapatite structure. Thanks to HAp’s high ion-exchange ability, silver can be introduced into its structure. The calcium ions present in the HAp structure can be easily replaced by silver ions to create a material endowed with high biocompatibility and antibacterial properties. The presented study is based on the analysis of the morphology of the modified powders via scanning electron microscopy (SEM), their chemical composition via X-ray energy dispersive spectroscopy (EDS) and chemical structure via X-ray diffraction (XRD) and Raman spectroscopy. The powders obtained through the ion exchange were mixtures of silver phosphates Ag3PO4 and HAp. The highest silver content was found in the sample modified with a 1M concentration of AgNO3 in the aqueous solution. It was also determined that the annealing of the obtained powders under vacuum at 800°C resulted in the formation of metallic silver and a change in the structure of HAp to β-TCP.
EN
The four-layer stack accumulative roll bonding (ARB) process using AA1050, AA5052 and AA6061 alloy sheets is performed up to 2 cycles without a lubricant at room temperature. The sample fabricated by the ARB is a multi-layer complex aluminum alloy sheet in which the AA1050, AA5052 and AA6061 alloys are alternately stacked to each other. The changes of microstructure and mechanical properties with annealing for the-ARBed aluminum sheet are investigated in detail. The as-ARBed sheet shows an ultrafine grained structure, however the grain diameter is some different depending on the kind of aluminum alloys. The complex aluminum alloy still shows ultrafine structure up to annealing temperature of 250℃, but above 275℃ it exhibits a heterogeneous structure containing both the ultrafine grains and the coarse grains due to an occurrence of discontinuous recrystallization. This change in microstructure with annealing also has an effect on the change of the mechanical properties of the sample. Especially, the specimen annealed at 300℃ represents abnormal values for the strength coefficient K and work hardening exponent n value.
5
EN
The article presents studies of phase transformations taking place in surface layers of nitrided steels as a result of their annealing at 520 °C for 5 and 10 h. Two steel grades were tested, the unalloyed AISI 1085 and the low-alloy AISI 52100. As a result of glow discharge nitriding, at 570 °C/5 h and 540 °C/12 h, respectively, nitrided layers were produced on the steels, consisting of a surface layer of iron nitrides with the structure of ε + γ′ and γ′ and of similar thickness 25. The study showed that during 5 h of annealing at 520 °C, the iron nitride layer already decomposed, which was documented by the analysis of chemical composition and X-ray analysis of the surface layers of steel. Comparative studies on the hardness distribution of surface layers of nitrided as well as nitrided and subsequently annealed AISI 52100 steels showed that after both 5 and 10 h of annealing, the hardness depth profiles were very similar and the effective thickness of the diffusion layer did not change. The results obtained enabled the demonstration that the emission of nitrogen into the atmosphere during annealing of nitrided steels is not accompanied by diffusion of nitrogen into the base layer. This proves that the iron nitride layer is not a source of nitrogen for the diffusion layer during annealing at reduced pressure.
EN
Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (tc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a tc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.
EN
Nanocrystalline zinc sulfide (ZnS) thin films are prepared on glass substrates by chemical bath deposition (CBD) method using aqueous solutions of zinc chloride, thiourea ammonium hydroxide along with non-toxic complexing agent tri-sodium citrate in alkaline medium at 80 °C. The deposition time and annealing effects on the optical and morphological properties are studied. The morphological, compositional, and optical properties of the films are investigated by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDAX) and UV-Vis spectroscopy. SEM micrographs exhibit uniform surface coverage. UV-Vis (300 nm to 800 nm) spectrophotometric measurements show transparency of the films (transmittance ranging from 69 % to 81 %), with a direct allowed energy band gap in the range of 3.87 eV to 4.03 eV. After thermal annealing at 500 °C for 120 min, the transmittance increases up to 87 %.
EN
In this paper, electrochemical properties of the as-formed and thermally treated titanium dioxide (TiO2) nanotubes with diameter in the range of 20–100 nm and height in the range of 100–1000 nm were presented. In addition, the effects of annealing temperature (450–550 °C) on the electrochemical characteristics of these structures, as well as the influence of diameter and height of TiO2 nanotubes on these properties were examined. The results were referred to a compact TiO2 layer (100 nm thick). Methods: The electrochemical test included open circuit potential, impedance spectroscopy and cyclic voltammetry measurements. The scanning electron microscope with energy dispersive spectroscopy analyser, x-ray photoelectron spectroscopy, and x-ray diffraction analysers were used for surface morphology characterisation as well as elemental, phase and chemical composition of TiO2 layers. Results: It was found that nanotubes with the diameter of 50 and 75 nm (height of 1000 nm) annealed at 550 °C exhibit the lowest impedance and phase angle values. However, the voltammetric detection of potassium ferricyanide indicated that the closest to 1 Ipc /Ipa ratio were shown by nanotubes with a diameter of 50 and 75 nm annealed at 450 °C. Conclusions: On the basis of performed analysis, it can be stated that the TiO2 layer with nanotubes of 50 nm in diameter and of 1000 nm in height, annealed in 450 °C may be indicated as the ones having the most favourable sensing and biosensing properties.
EN
Nanocrystalline zinc sulfide thin films were prepared on glass substrates by chemical bath deposition method using aqueous solutions of zinc chloride, thiourea ammonium hydroxide along with non-toxic complexing agent trisodium citrate in alkaline medium at 80 °C. The effect of deposition time and annealing on the properties of ZnS thin films was investigated by X-ray diffraction, scanning electron microscopy, optical transmittance spectroscopy and four-point probe method. The X-ray diffraction analysis showed that the samples exhibited cubic sphalerite structure with preferential orientation along 〈2 0 0〉 direction. Scanning electron microscopy micrographs revealed uniform surface coverage, UV-Vis (300 nm to 800 nm) spectrophotometric measurements showed transparency of the films (transmittance ranging from 69 % to 81 %), with a direct allowed energy band gap in the range of 3.87 eV to 4.03 eV. After thermal annealing at 500 °C for 120 min, the transmittance increased up to 87 %. Moreover, the electrical conductivity of the deposited films increased with increasing of the deposition time from 0.35 × 10−4 Ω·cm−1 to 2.7 × 10−4 Ω·cm−1.
EN
Microstructures and mechanical properties of as-cast Al-6.5Mg-1.5Zn-0.5Fe alloys newly alloy-designed for the parts of automobile were investigated in detail. The aluminum (Al) sheets of 4 mm thickness, 30 mm width and 100 mm length were reduced to a thickness of 1 mm by multi-pass rolling at ambient temperature and subsequently annealed for 1h at 200~500°C. The as-cast Al sheet was deformed without a formation of so large cracks even at huge rolling reduction of 75%. The recrystallization begun to occur at 250°C, it finished at 350°C. The as-rolled material showed tensile strength of 430 MPa and tensile elongation of 4.7%, however the specimen after annealing at 500°C showed the strength of 305 MPa and the elongation of 32%. The fraction of high angle grain boundaries above 15 degree increased greatly after annealing at high temperatures. These characteristics of the specimens after annealing were discussed in detail.
EN
Purpose: This paper aims to assess microstructures and mechanical properties of annealed and un-annealed Al-Li alloys (AA8090) and provide valid information regarding influence of anisotropy on tensile properties, fatigue lives. Design/methodology/approach: The methodology included investigating the influence of annealing on grain size, tensile strength and fatigue lives of AA8090. Optical microscope, scanning electron microscope and X-ray diffraction were utilized to analyse the crystallographic texture. Findings: The results showed that the un-annealed alloy exhibited much finer grain structure in three directions, namely longitudinal (L) rolling direction, L-45° and Long transverse (LT) combined with stronger crystallographic texture. Regarding to mechanical properties, un-annealed alloy presented superior tensile strength with strong anisotropic behaviour. L and LT grains direction showed highest tensile strength value of 550 MPa and L-45° showed lowest tensile strength value of 420 MPa. Results of fatigue test revealed that annealed Al-Li alloy has lower fatigue lives with high influence of test direction on fatigue properties. Higher variation in fatigue life to failure links with un-annealed alloy over annealed alloy. Examination of fractured surface showed that the morphology of fractured surface is a mixture of ductile and brittle fractures in both annealed and un-annealed alloys with more brittle behaviour in un-annealed alloy. Research limitations/implications: The main challenge of this work is the determination of the test direction (test angle in respect to rolling direction), which is necessary to provide correct information regarding mechanical properties. Further study of low cycle fatigue can be done in future, which will be an excellent indication to mechanical properties of this alloy since it provides more understanding to the behaviour of the material and better comprehend crack propagation and strain stress concentration. Practical implications: AA8090 alloy is an important candidate for aerospace and aircraft industries. Influence of annealing heat treatment and rolling direction on mechanical properties of AA8090 alloy provides more accurate information to the manufacturers who deal with this alloy. Originality/value: This study is affording a significant information regarding the effect of annealing and anisotropic behaviour on mechanical properties of AA8090. To our knowledge, there are few reports that study this combination of factors on AA8090 alloy.
EN
An analysis has been carried out of the influence of annealing time at the preheating temperature of 650 °C on the change in hardness and alloy structure of lamellar graphite cast iron in the working as well as in the laboratory conditions. This preheat temperature is common during reclaiming welding of castings with complex shapes. The changes in unalloyed cast iron EN-GJL 200 to EN-GJL 300 according to ISO 1690 standard and cast iron with low amount of elements such as Sn, Cu, Cr, and Mo and their combinations were assessed. It was found that the cast iron of higher strength grades has better hardness and structural stability. Cast iron alloyed with chromium or its combinations has the highest stability. In unalloyed cast iron, a partial degradation of pearlite occurs; in alloyed cast iron the structural changes are not conclusive.
EN
The temperature of annealed steel coils is a determining variable of the future steel sheets quality. This variable also determines the energy consumption in operation. Unfortunately, the monitoring of coil inner temperature is problematic due to the furnace environment with high temperature, coil structure, and annealing principle. Currently, there are no measuring principles that can measure the temperature inside the heat-treated product in a non-destructive manner. In this paper, the soft sensing of inner temperature based on the theory of non-stationary heat conduction and approach based on Support Vector Regression (SVR) was presented. The results showed that a black-box approach based on the SVR could replace an analytic approach, though with lesser performance. Several annealing experiments were performed to create a training data set and model performance improvement in the estimation of inner coil temperatures. The proposed software based on non-stationary heat conduction can calculate the behavior of inner coil temperature from the measured boundary temperatures that are measured by thermocouples. The soft-sensing principles presented in this paper were verified under laboratory conditions and on the data obtained from a real annealing plant.
PL
W przeglądowej formie przedstawiono wyniki dotychczasowych badań szybkokrystalizowanych stopów aluminium, które wykonano w latach 1999–2016 w ramach współpracy naukowo-badawczej Wydziału Metali Nieżelaznych AGH i Nihon University w Tokio. Zastosowanie rozpylania ciekłego stopu na powierzchnię intensywnie chłodzonego walca miedzianego pozwoliło uzyskać cienkie płatki metaliczne, które następnie konsolidowano mechanicznie w procesie prasowania, odgazowania próżniowego i wyciskania. Badano materiały zawierające dodatki stopowe takie, jak Si, Mn, Fe, Ni, Co oraz typowy skład dla wybranych stopów serii 7000 (Mezo10 i Mezo20). Wyróżniono trzy grupy materiałów różniących się trwałością efektu rozdrobnienia składników strukturalnych po szybkiej rekrystalizacji. W warunkach wyżarzania w podwyższonej temperaturze najbardziej stabilne wydzielenia (Si) stwierdzono w stopach RS Al-Si. Stopy RS zawierające metale przejściowe takie, jak Fe, Ni, Mn, Co charakteryzują się umiarkowanie stabilną morfologią wydzieleń, które ulegają bardzo powolnej koagulacji w wysokiej temperaturze, lecz nie osiągają rozmiarów typowych dla materiałów wytwarzanych w technologiach przemysłowych. Stwierdzono, że szybka krystalizacja wymienionych stopów znacząco zwiększa nie tylko własności wytrzymałościowe, ale również plastyczność powyższych stopów. Do trzeciej grupy szybko-krystalizowanych materiałów należą wyroby ze stopów serii 2000, 6000, 7000, które w technologiach przemysłowych poddaje się umocnieniu w procesie starzenia. Pokazano przy-kłady badań strukturalnych i mechanicznych stopów Mezo10 i Mezo20 (seria 7000). Materiały RS wykonane z tych stopów charakteryzują się obecnością wydzieleń o wymiarach 0,5–1,5 µm zawierających podstawowe dodatki stopowe Zn, Mg, Mn. Obecność tych wydzieleń wynika z procesu szybkiej krystalizacji, który nadaje cechy struktury odmienne od przewidywanych zgodnie z wykresem równowagi termodynamicznej.
EN
This review presents the results of studies on rapidly-solidified (RS) aluminum alloys that have been performed during the years 1999-2016 as part of scientific and research cooperation program between the Faculty of Non-ferrous Metals at AGH and Nihon University in Tokyo. The application of liquid alloy spraying onto the intensively cooled and rotating copper cylinder made it possible to obtain thin metallic flakes, which were then consolidated mechanically in the process of pressing, vacuum degasification and extrusion. Materials containing alloying elements such as Si, Mn, Fe, Ni, Co, and selected AA7000series alloys (Mezo10 and Mezo20) were studied. Three groups of materials were distinguished, differing in the persistence of the refinement effect on structural components following rapid recrystallization. Under annealing conditions at elevated temperature, the most stable precipitates (Si) were observed in RS Al-Si alloys. RS alloys containing transitional metals such as Fe, Ni, Mn and Co are characterized by a moderately stable morphology of precipitates, which undergo very slow coarsening at high temperature but do not reach the sizes typical for materials manufactured by industrial technologies. It was found that rapid crystallization of the aforementioned alloys significantly in-creases not only their strength properties but also their plasticity. The third group of rapidly-solidified materials include products made of 2000-, 6000- and 7000-series alloys, which are usually hardened by means of aging process in industrial technologies. Examples of structural and mechanical tests conducted on the Mezo10 and Mezo20 (7000-serie alloys) are shown. RS materials made from these alloys are characterized by the presence of precipitates with sizes of 0.5-1.5 µm, containing basic alloying elements, i.e. Zn, Mg, Mn. The presence of these precipitates arises from the rapid crystallization process, which bestows structural features different from those expected according to the thermo-dynamic equilibrium (phase) diagram.
EN
Our research focused on Inconel 625 weld overlays on 16Mo3 steel boiler pipes. The investigation focused on the characterization of changes in the microstructure and chemical composition after annealing. The annealing was performed for ten hours at temperatures from 600 to 1000°C. Changes in the microstructure were observed with a scanning and transmission electron microscope (SEM and TEM). The investigation was supplemented by hardness measurements.
PL
Badania przeprowadzono na napoinach ze stopu Inconel 625 na stali kotłowej 16Mo3. Skoncentrowano się na charakterystyce mikrostruktury i składu chemicznego zmian po wyżarzaniu. Obróbkę cieplną przeprowadzono w temperaturze od 600 do 1000°C przez 10 godzin. Zmiany mikrostruktury obserwowano przy użyciu skaningowej i transmisyjnej mikroskopii elektronowej (SEM i TEM). Badania zostały uzupełnione o pomiary twardości.
EN
This paper reports on the development of an oven with a special purpose electronic board and specialist materials such as basalt fiber and nichrome. It is designed for optical resonators which are temperature controlled during their annealing process to increase their quality factor for the purpose of photonics applications.
EN
In this paper, we report the complex crystallization kinetics of phase transition happening in Ti-Cu-based bulk metallic glasses (BMGs), which play significant roles in the glass formation with respect to their low reduced glass transition temperatures, Trg. The first exothermic event just occurs when annealing the BMG samples in the supercooled liquid region, leading to the Avrami exponent deviating from conventional modes affected by the residual amorphous phase. For Ti43Cu43Ni7Zr7 BMG, the plasticity can be improved by pre-annealing at a sub-Tg temperature of 623K (≈50K below Tg) for 0.5 hour, however, deteriorated by 1 hour annealing, which could be related to the change in stability of this BMG against crystallization with different pre-annealing times.
EN
This paper shows results of researches of a structure and mechanical properties of metal sheets of IF steels subjected to recrystallization annealing. The annealing was held in the scope of the temperature of 600-900°C over 25 min time. The impact of heat treatment on changes of properties and structure of the researches steel has been analysed. During annealing typical processes of rebuilding of the structure deformed as a result of cold deformation in the form of forming new recrystallized grains and their growth were observed. As the temperature of annealing increases the hardness of the material gradually decreases.
PL
Prowadzenie procesu odprężania szkła nie jest proste w sytuacji, gdy w zakładzie wytwarzane są przedmioty o różnorodnym kształcie i wielkości, ze szkła dmuchanego i szkła pełnego, w małych seriach. Taka produkcja wymaga zoptymalizowania procesu obróbki cieplnej (odprężania), ponieważ wyroby z pełnego szkła – takie jak galanteria szklana – przy zbyt wysokiej górnej temperaturze odprężania mogą ulegać deformacjom (są jeszcze plastyczne). Z kolei zbyt niska temperatura procesu nie pozwala na eliminację naprężeń wewnętrznych. W artykule przedstawiono, w jaki sposób wyniki badań naprężeń wewnętrznych przeprowadzonych dla kilku reprezentatywnych wyrobów produkowanych w krakowskim Oddziale Instytutu Ceramiki i Materiałów Budowlanych wpłynęły na zmianę prowadzenia procesu odprężania szkła.
EN
Conducting of the glass annealing process is not an easy one in a situation when in a factory artefacts of different shapes and sizes are produced, from blown and from thick glass, in short series. This kind of production requires the optimization of annealing process because the artefacts from thick glass – glass animals, flowers, paperweights can be distorted due to too high upper annealing temperature. Excessively low upper annealing temperature, by contrast, precludes the release of interior stresses. The paper presents the results of interior stresses tests conducted for several representative artefacts produced in Kraków Division of Institute of Ceramics and Building Materials and shows how they influenced the conducting of the glass annealing process.
PL
Artykuł dotyczy badań zrealizowanych na stopach AZ31 i AZ61. Materiały te zostały wytworzone w IMN OML Skawina w postaci wlewków o średnicach 102 mm. Następnie w procesie przeciwbieżnego wyciskania wytworzono z nich rury. Określono strukturę wyjściową i własności mechaniczne w podstawowych stanach obróbki cieplnej. Kolejnym etapem było poddanie wyrobów wyciskanych wyżarzaniu w temperaturach od 100 do 450°C, w celu określenia możliwości podniesienia plastyczności badanych stopów, aby umożliwić ich kształtowanie na zimno. W wyniku wyżarzania obniżono twardość stopów z ~60HB do ~40HB. Do końcowych badań wytypowano temperaturę wyżarzania 400°C, dla której przy nieznacznym spadku własności wytrzymałościowych, uzyskano dla badanych stopów wzrost wydłużenia A10 z ok. 10 do 20%. Pozwoliło to na kształtowanie rur ze stopów magnezu na zimno w procesie gięcia, uzyskując kąt gięcia powyżej 90°.
EN
The paper presents investigations conducted on AZ31 and AZ61 magnesium alloys. Material for test were casted Ø102 mm billets made IMN OML Skawina. From those billets tubes were extruded in indirect mode. After extrusion process both structural and mechanical tests have been done. Next step was heat treatment of extruded tubes in the range of 100–450°C to determine the possibility to improve their workability in cold bending process. As a result the hardness of the material decreased from ~60HB to ~40HB. For final tests annealing temperature has been set to 400°C what has resulted in significant increase of plastic elongation (from A10 = 10% to more than A10 = 20%) with inconsiderable decrease of mechanical properties. Consequently the possibility of tubes cold bending has been achieved with bending angle above 90°.
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