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Wire-feed assisted A-TIG welding of dissimilar steels

Sharma Pratishtha, Dwivedi Dheerendra Kumar

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 2

672--691

EN

This study investigates the activated flux-tungsten inert gas welding (A-TIG) welding of dissimilar P92 steel-304H ASS using ‘wire feed’ (patent pending) in terms of weld pool mixing behavior, microstructure and mechanical properties of the weld joint. ErNiCrMo-3 wire was fed during welding and three-wire feeding configurations were analyzed in view of filler wire melting and weld pool mixing behavior. The metal from filler wire is transferred into the weld pool in the form of ‘interrupted liquid bridge’ and ‘uninterrupted liquid bridge.’ The ‘uninterrupted liquid bridge’ melting resulted in homogeneous mixing of filler wire into the weld pool. The weld joint produced using the best wire feeding configuration was characterized and compared with the weld joint developed without wire feed. Microstructure alterations were realized with the use of wire feed. The weld zone with wire feed exhibited a fully austenitic structure, whereas; the completely martensitic structure was obtained using A-TIG welding without wire feed. The microstructural transformation led to the improvement of ductility and impact toughness of weld joint without substantial loss of tensile strength. The total elongation and impact toughness of the A-TIG weld joint with wire feed was 45.9% and (89 ± 2) J, respectively, which were significantly higher in contrast to the A-TIG weld joint without wire feed [total elongation: 37.4% and impact toughness: (30 ± 2) J].

2

Badanie zróżnicowania składu chemicznego Cr spineli w obrębie masywu skał ultramaficznych na przykładzie SE Kosowa : zastosowanie w poszukiwaniach i wzbogacaniu rud chromu

Ożóg Magdalena, Pieczonka Jadwiga, Piestrzyński Adam, Ćwiertnia Tomasz

Przegląd Geologiczny

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2019

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Vol. 67, nr 3

186--188

EN

New data on chemistry of Cr spinels hosted within the ultramafic massif located in SE Kosovo show variations in their primary composition, which depends on ore and rock types. Spinels form disseminated and vein type ores and accessory spinels in peridotites are characterized by lower Cr and higher Fe concentrations in comparison to spinels making up massive ores. Concentrations of these metals increase in altered spinels both in ores and peridotites. Contents ofMn and Zn tend to be higher in accessory spinels than in spinels occurring in ores. The lower Cr:Fe ratio for Cr-rich spinels in disseminated ores in relations to chromite in massive ores may have an influence on their industrial usefulness. The use of EPMA-WDS technique for detrital spinels should be considered as an effective tool for chromium deposit exploration, especially in greenfield projects, to assess an ultramafic massifpotential for hosting rich ores. Chemical analyses of spinels are recommended in planning a beneficiation process for the low-grade chromite ores, in order to obtain high quality concentrates.

3

Determination of chemical composition of (Pb,La)(Zr,Ti)O3 type ferroelectric ceramics by WD-XRF and ED-EPMA

Sitko R., Zawisza B., Płońska M., Malicka E.

Chemia Analityczna

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2008

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Vol. 53, No. 1

123-131

EN

The stoichiometry determination of lanthanum doped lead zirconate titanate (PLZT) by the wavelength-dispersive X-ray fluorescence spectrometry (WD-XRF) and energy-dis-persive-electron-probe microanalysis (ED-EPMA) is presented. For WD-XRF measurements the analyzed materia! was mixed with boric acid in the ratio 1:20 and pressed into pellets. The multielement standard samples were prepared by mixing appropriate amounts of analyte oxides (PbO, TiO2, ZrO2 and La2O3,) with boric acid. The obtained results were compared with the analysis of PLZT performed by ED-EPMA. The matrix effects were corrected using threoretical influence algorithm for intermediate-thickness samples (WD-XRF) and ZAP method (ED-EPMA).

PL

Przedstawiono metodę oznaczania stechiometrii tytanianu i cyrkonianu ołowiu domieszkowanego lantanem (PLZT) z wykorzystaniem rentgenowskiej spektrometrii fluorescencyjnej z dyspersją długości fali (WD-XRF) i mikroanal izy rentgenowskiej zdyspersjąenergii (ED-EPMA). Do pomiarów WD-XRF analizowany materiał był mieszany z kwasem borowym w stosunku l :20 i prasowany w pastylkę. Wielopierwiastkowe próbki wzorcowe były przygotowane przez zmieszanie odpowiednich ilości tlenków analitów (PbO, TiO2ZrO2 i La2O3) z kwasem borowym. Uzyskane rezultaty porównano z wynikami ED-EPMA. Efekty matrycy korygowano za pomocą algorytmu teoretycznych współczynników wpływów dla próbek o grubości pośredniej (WD-XRF) oraz metodą ZAF (ED-EPMA).

4

New results about the Al-Cr binary phase diagram

Mahdouk K., Gachon J.

Archives of Metallurgy

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2001

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Vol. 46, iss. 3

233-238

EN

The Al-Cr phase diagram has been revisited, in the composition range from 6 to 46 at.% Al, by means of differential thermal analysis (DTA). X-ray diffraction (XRD) and electron probe microanalysis (EPMA). The intcrmetallic compounds of this system and the Cr solid solution were investigated by direct reaction calorimetry at high temperatures. The experimental enthalpies of formation were compared with available literature data. Partial enthalpies of dissolution of Cr in liquid Al were determined at 1001 and 1106°C.

PL

Metodami różnicowej analizy termicznej (DTA). dyfrakcji rentgenowskiej (XRD) oraz mikroanalizy elektronowej (EPMA) poddano weryfikacji układ Al-Cr w zakresie stężeń pomiędzy 6 a 46% atomowych Al. Za pomocą kalorymetru przebadano w wysokich temperaturach fazy międzymetaliczne tego układu oraz roztwór stały (Cr). Uzyskane doświadczalne wartości ciepła tworzenia porównano z dostępnymi danymi z literatury. Określono cząstkowe ciepła rozpuszczania Cr w ciekłym Al w przedziale temperatur 1001 do 1106°C.