Wyniki wyszukiwania - Biblioteka Nauki

1

Effect of Forge Application on Microstructural and Mechanical Properties of AISI 316 Using Direct Drive Friction Welding Process

100%

Hassan J. A. , Boukharouba T. , Miroud D.

Archives of Metallurgy and Materials

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2022

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tom Vol. 67, iss. 3

987--992

EN

Present study introduces effect of forge application and elimination on microstructural and mechanical properties of AISI 316 during friction welding. Temperature measurements, microstructure, micro-hardness, tensile test, scanning electron microscopy and X-ray diffraction were evaluated. Maximum temperature recorded was 819°C while forge was applied between 357°C-237°C. Thermo-mechanically affected zone and highly plastically deformed zone were created at the interface at elimination and application of forge respectively. Ultimate tensile strength decreased and ductility increased when forge elimination compared to forge application. Tensile fracture was occurred adjacent to the welding interface for both cases, though, after forge application, ductile fracture mode and cleavage features through the fingerprints were observed in the fracture morphology. Redistribution and concentration of gamma iron in 111 level after forge application and heat treated of AISI 316.

2

Evolution and Characterization of Zirconium 702 alloy at various temperatures

86%

Lade J. , Dharavath B. , Badrish A. , Kosaraju S. , Singh S. K. , Saxena K. K.

Archives of Metallurgy and Materials

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2023

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tom Vol. 68, iss. 2

807--812

EN

The Zirconium 702 alloy effectively used in nuclear industry at various critical conditions like high temperature and high pressure. This survey is an assessment of insights into the mechanical properties of the metal when exposed to different temperatures along the rolling direction.The main objective of this work is to characterize the tensile properties, and fracture study of broken tensile test samples at various temperatures.The tensile samples tested in our current work are 100°C, 150°C, and 200°C temperatures in different directions (0°, 45°, 90°) along with the rolling direction of the sheet. It is evident from the experimental results that temperatures significantly affect material properties. Temperature increases cause % elongation to increase, and strength decreases. ANOVA analysis revealed that temperature significantly influenced ultimate tensile strength (UTS), and yield strength (YS), as well as % elongation.The temperature contribution for UTS, YS, and % elongation is 41.90%, 31.60%, and 77.80% respectively. SEM fractured images showing the ductile type of behavior for all the temperatures.

3

Investigation and optimization of friction stir welding process parameters of stir cast AA6082/ZrO2/B4C composites

86%

Umar M. J. , Palaniappan P. K. , Maran P. , Pandiyarajan R.

Materials Science Poland

|

2020

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tom Vol. 38, No. 4

715--730

EN

In the present investigation, aluminium-based alloy (AA6082) is stir-casted with 3 % ZrO2 and 5 % B4C reinforcement particulates to fabricate Aluminium Metal Matrix Hybrid Composites (AMMHCs) which are further friction-stir welded at different welding conditions to develop a welded joint with optimum ultimate tensile strength (UTS) and microhardness. This newly developed AMMHC will find its specific application as bulkhead partitions in the hull of a ship due to its excellent properties, such as lower weight, higher specific strength, superior resistance to wear, and lower thermal expansion coefficient than that of AA6061 and AA5083 composites. The friction-welded butt joints performance of AA6082/3%ZrO2/5%B4C is generally determined by varying the FSW process parameters such as tool rotational speed (TRS), welding speed (WS), axial load (AL), tool tilt angle (TTA), tool pin profile (TPP), shoulder diameter (SD), etc. In the present work, the empirical relationships are established between parameters highly influencing FSW process (TRS, WS, and AL) and their responses (UTS and weld nugget microhardness (WNH)). The desirability approach is employed for predicting the optimal UTS and WNH. The corresponding values of input process parameters are TRS of 1030.95 rpm, WS of 38.5 mm/min, and AL of 5.88 kN. The calculated UTS and WNH for the present investigation are 239.98 MPa and 94.2 HV, respectively, and these values are consistent with the results of validation experiments.

4

Highsilicone Austempered Ductile Iron

86%

Kochański A. , Krzyńska A. , Radziszewski T.

Archives of Foundry Engineering

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2014

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tom Vol. 14, iss. 1

55--58

EN

Ductile iron casts with a higher silicone content were produced. The austempering process of high silicone ductile iron involving different austempering times was studied and the results presented. The results of metallographical observations and tensile strength tests were offered. The obtained results point to the fact that the silicone content which is considered as acceptable in the literature may in fact be exceeded. The issue is viewed as requiring further research.

5

Experimental and numerical small punch tests of the 14cr ods ferritic steel

86%

Nowik K. , Oksiuta Z.

Acta Mechanica et Automatica

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2022

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tom Vol. 16, no. 3

225--232

EN

Nowadays, various small specimen test techniques have gained wide popularity and appreciation among researchers as they offer undoubtful benefits in terms of structural material characterisation. This paper focuses on small punch tests (SPTs) performed on small-sized disc specimens to assess the mechanical properties of 14Cr oxide dispersion strengthened (ODS) steel. A numerical model was established to support experimental data and gain deeper insight into complex strain states developing in a deformed specimen. Modern evaluation procedures were discussed for obtaining mechanical properties from the small punch force-deflection response and were compared with the literature. Applicability and universality of those relations at different test conditions were also studied. It appeared that different ball diameters used had negligible influence on yield point but strongly affected ultimate strength estimation. It was found that friction belongs to decisive factors determining strain distribution in samples, as dry conditions increase the peak strain and move its location farther from the punch pole.

6

Influence CuAl10Fe3Mn2 Additive on Ultimate Tensile Strength and WEAR of Al-9%SiMg Alloy

72%

Lipiński T.

Tribologia

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2018

|

tom nr 3

83--89

EN

One of the most common castings applied in industrial production is aluminium-silicon alloy (ca. 9% Si with Mg). The Al-SiMg alloys have high corrosion resistance, high strength to weight ratio with modifications, very good castability, a low thermal-expansion coefficient, and relatively good wear resistance. These properties make it possible to widely apply the foundry Al-9% SiMg alloy to number of aviation, automotive, and others materials working on tribological applications. Similar to silumins, the aluminium bronze CuAl10Fe3Mn2 is characterized by good mechanical properties and wear and corrosion resistance. This paper presents the research on the treatment of Al-9%SiMg alloy with a composition of CuAl10Fe3Mn2 in different mass ranges. The experiments were conducted by a factor plan 23 for three independent variables. The main additions were strontium, Al-9%SiMg, aluminium bronze, as well as pure or melted with raw silumin. The effect of the tested additions on the microstructure and tensile strength of the Al-9%SiMg alloy was presented in figures. All analysed parameters (mechanical and tribological) of the hypo-eutectic Al-9%SiMg alloy with tested bronze additions are improved. Based on the analysis of the study results, it was found that the microstructure and tensile strength of the tested alloy are determined through the contents introduced of CuAl10Fe3Mn2 to the alloy.

PL

Jednym z najczęściej stosowanych w produkcji przemysłowej stopów odlewniczych jest stop aluminium--krzem (ok. 9% Si z dodatkiem Mg). Stopy Al-SiMg charakteryzują się wysoką odpornością na korozję, w stanie zmodyfikowanym wysokim stosunkiem wytrzymałości do wagi odlewu, bardzo dobrą lejnością, niskim współczynnikiem rozszerzalności cieplnej, względnie dobrą odpornością na zużycie. Te właściwości umożliwiają szerokie zastosowanie odlewniczego stopu Al-9% SiMg do wielu materiałów lotniczych, motoryzacyjnych i innych pracujących również w zastosowaniach tribologicznych. Podobnie jak w przypadku siluminu brąz aluminiowy CuAl10Fe3Mn2 charakteryzuje się dobrymi właściwościami mechanicznymi, zużyciem i odpornością na korozję. W artykule przedstawiono badania dotyczące obróbki stopu Al-9% SiMg składnikiem CuAl10Fe3Mn2 w różnych zakresach masowych. Eksperymenty przeprowadzono za pomocą planu czynnikowego 23 dla trzech niezależnych zmiennych. Głównym dodatkiem były: stront Al-9%SiMg, brąz aluminiowy, zarówno czysty, jak i stopiony z surowym siluminem. Wpływ badanych dodatków na mikrostrukturę i wytrzymałość na rozciąganie stopu Al-9% SiMg przedstawiono na rysunkach. Wszystkie analizowane parametry (mechaniczne i tribologiczne) stopu podeutektycznego Al-9% SiMg z badanym dodatkiem brązu zostały poprawione. Na podstawie analizy wyników badań stwierdzono, że mikrostruktura i właściwości mechaniczne badanego stopu są określone przez zawartość CuAl10Fe3Mn2 wprowadzoną do stopu.

7

A comparison of the breaking strength of samples of parts made from pure and regrind polypropylene

72%

Jałbrzykowski M. , Obidziński S.

Journal of Research and Applications in Agricultural Engineering

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2017

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tom Vol. 62, nr 1

55--58

EN

This paper presents the results of tests of selected mechanical properties of parts made from injection molded polypropylene (PP). Parts made from primary (pure) 100 [%] PP as well as parts made from 100 [%] regrind were used for the tests. Discussed was the problem of using reground material in injection molding. Attention was paid to the apparent lack of adverse influence of regrind on the assessed mechanical properties of injection molded polypropylene parts.

PL

W pracy przedstawiono wyniki wybranych właściwości mechanicznych detali wykonanych z polipropylenu (PP) metodą wtrysku. Do badań wykorzystano detale wykonane w 100% z pierwotnego (czystego) PP oraz detale wykonane w 100% z przemiału. Poruszono problem możliwości wykorzystania tworzywa wtórnie mielonego w produkcji wtryskowej. Zwrócono uwagę na brak wyraźnego negatywnego wpływu przemiału na oceniane właściwości mechaniczne wtryskiwanych detali tworzywowych.

8

Properties and Structure of High-Silicone Austempered Ductile Iron

72%

Krzyńska A. , Kochański A.

Archives of Foundry Engineering

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2014

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tom Vol. 14, iss. 2

91--94

EN

The results presented in this paper are a continuation of the previously published studies. The results of hest treatment of ductile iron with content 3,66% Si and 3,80% Si were produced. The experimental castings were subjected to austempering process for time 30, 60 and 90 minutes at temperature 300oC. The mechanical properties of heat treated specimens were studied using tensile testing and hardness measurement, while microstructures were evaluated with conventional metallographic observations. It was again stated that austempering of high silicone ferritic matrix ductile iron allowed producing ADI-type cast iron with mechanical properties comparable with standard ADI.

9

Influence of gating system design on tensile properties of AlSi7Mg0.3 alloy

72%

Kasala J. , Pernis R. , Čaplovič L.

Archives of Foundry Engineering

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2010

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tom Vol. 10, iss. 1 spec.

117--120

EN

Aluminium-silicon castings are typically produced by gravity casting. Bottom gated systems are usually required if surface turbulence is to be eliminated. Latest research has demonstrated, that for every liquid metal there is critical velocity above which the surface will fold over and entrain itself in the bulk of the metal. Therefore the strength properties the aluminium castings are largely determined by microstructural defects, particularly pores and oxide films which are created by surface turbulence. The purpose of this paper is to investigate tensile properties and microstructure of aluminium alloy in a casted state two different designs of gating system. The first is the usual bottom gating system and the second is novel design of gating system named a vortex-gate introduced by Campbell [1]. The results of the mechanical tests revealed that there is a small improvement in ultimate tensile strength for vortex-gate design of pouring system. The oxide film defects were observed in microstructure of a sample taken from poured casting by using the bottom gated system.

10

Określanie parametrów wytrzymałościowych stali w istniejących konstrukcjach

72%

Szumigała M. , Chybiński M. , Polus Ł.

Materiały Budowlane

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2016

|

tom nr 11

78--79

PL

W artykule omówiono problemy dotyczące ustalenia podstawowych właściwości wytrzymałościowych stali, z których wykonano elementy konstrukcyjne, w przypadku, gdy nie zachowała się żadna dokumentacja projektowa. Przedstawiono wybrane metody służące ocenie parametrów wytrzymałościowych stali oraz przykłady, w których te metody zostały zastosowane.

EN

The paper presents the problems with evaluation of basic strength parameters of steel structural elements. There are no documentations of these elements. The authors show selected methods to evaluate ultimate tensile strength. These methods were used in examples presented in this paper.

11

Effect of novel grain refiner and Ni alloying additions on microstructure and mechanical properties of Al-Si9.8-Cu3.4 HPDC castings – optimization using Multi Criteria Decision making approach

72%

Apparao K. C. , Bannaravuri P. K. , Pulisheru K. S. , Francis E. D. , Sunny K. A. , Babu R. G. , Daniel P. F. , Kumar Birru A.

Materials Science Poland

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2022

|

tom Vol. 40, No. 1

9--24

EN

Studies dealing with process improvement of aluminum alloys and their grain structure refinement are the current area of interest in casting companies and foundries, the aim being to enhance the properties of the base metal. In this study, the microstructural and mechanical properties of commercial Al-Si9.8-Cu3.4 alloy die castings influenced by different additions of Al-3.5FeNb-1.5C master alloy (viz. 0 wt.%, 0.1 wt.%, and 1.0 wt.%) as a new grain refiner and Al-6Ni master alloy (viz. 0 wt.%, 0.5 wt.%, and 5.0 wt.%) as an alloying element have been investigated. A multi-criteria decision-making approach for the improvement of the die casting process was performed using grey relational analysis (GRA) and TOPSIS analytical techniques. It was observed that the primary aluminum α-grains were significantly refined, particularly at the lower addition level 0.1 wt.% of Al-3.5FeNb-1.5C, and conversely, poor grain refining efficiency was observed at a higher addition level 1.0 wt.% of Al-3.5FeNb-1.5C. Due to the refinement by Al-3.5FeNb-1.5C grain refiner and the effect of Ni alloying element additions, the ultimate tensile strength (UTS) and hardness (Brinell and micro) of the Al-Si9.8-Cu3.4alloy are improved, particularly at 0.1 wt.% of Al-3.5FeNb-1.5C and 0.5 wt.% of Al-6Ni master alloys. Quantitatively, UTS, Brinell hardness, and microhardness values have been increased by 12.3%, 7.0%, and 20%, respectively.

12

Underwater friction-stir welding of a stir-cast AA6061-SiC metal matrix composite: optimization of the process parameters, microstructural characterization, and mechanical properties

72%

Sabry I. , Hewidy A. M.

Materials Science Poland

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2022

|

tom Vol. 40, No. 1

101--115

EN

It is an underlying fact for the case of the joining process especially welding to have optimized parameters to achieve joints with outstanding mechanical characteristics. In the current article, using stir-cast aluminum-based alloy (Al 6061) is stir-cast with Al 6061/5%wt. silicon carbide, Al 6061/10%wt. silicon carbide, and Al 6061/18%wt. silicon carbide was welded using an underwater friction-stir welding process. Optimum welding parameters [namely, tool rotating speed (N), welding speed (S), and silicon carbide (SiC)] are investigated using analysis of variance (ANOVA) and response surface methodology (RSM) statistical approaches. High ultimate tensile strength and microhardness were set as required characteristics of quality welds. Since there are two responses and two objectives, multiple-criteria decision-making approach-response surface methodology was performed alongside ANOVA. Optimal parameters from these statistical approaches are converged to a tool rotating speed of 1,736.36 rpm, a welding speed of 11.58 mm/min, and a SiC of 16.67%, respectively. For the current inquiry, the computed ultimate tensile strength and microhardness are 984 MPa and 89.9 HV, respectively, and these values are congruent with the findings of effectiveness studies. It is deduced from this study that the optimal parameters are convergent irrespective of the two used techniques for the investigated experimental data.

13

Complex silumins

58%

Pietrowski S.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

tom Vol. 24, nr 1

101-105

EN

Purpose: The study presents the results of investigations carried out on silumins with additions of Mg, Ni, Cu, Cr, Mo and W. The silumins containing Mg, Cu and Ni are well-known and commonly used in construction of machines and equipment. Design/methodology/approach: Additions of Cr, Mo and W have not been thoroughly investigated yet. They are considered a new family of innovative cast aluminium alloys. Findings: In Al-Si systems they form silicides, like Cr3Si, Mo3Si, W3Si and intermetallic phases of Al13Cr4Si4, Al12Mo, Al12W and AlWSi. The silicides crystallise in cubic lattice of parameters similar to aluminium and silicon. Research limitations/implications: Therefore they can act as crystallisation substrates and occur as separate phases. The examinations under the microscope and X-ray microanalysis of the linear and point distribution of elements confirmed the presence of the above mentioned phases. A combination of two elements, e.g. Cr and Mo, or Cr and W, was observed to cause the formation of complex silicide layers of Mo3Si and (Cr, Mo)3Si, or Cr3Si as well as (W, Cr)3Si. Originality/value: The presence of the silicides has been indicated as a possible source of the refinement of alpha (Al) and beta (Si) phases. The precipitations of these phases and of the intermetallic phases favour a high degree of the silumins hardening. A characteristic feature is the fact that nucleation and crystallisation of the successive phases takes place at the phase boundaries formed between the previously precipitated phase and solid solution alpha. The studies carried out so far have indicated that in complex silumins at high temperatures crystallise the silicides and peritectic phases of Al12W, AlWSi, Al12Mo and Al13Cr4Si4. Phases alpha or beta are the next ones to crystallise, followed by complex eutectic alpha + beta +Al(Si, Cr, Mo, W, Fe). Further crystallise the phases of Mg2Si, Al3Ni and Al2Cu. The silumins presented here are characterised by high mechanical properties: Rp0,2=320-420MPa, Rm=400-520MPa, A5=0.5-5.0% and elevated hardness of 145-210HB. Further investigations will be carried out to optimise the chemical composition of silumins and the precipitation hardening process parameters to produce alloys characterised by optimum combination of strength, ductility and hardness.

14

Wpływ obróbki cieplnej i plastycznej na strukturę i właściwości mechaniczne stopu na osnowie fazy międzymetalicznej Ni3Al

58%

Jóźwik P. , Bojar Z. , Zasada D. , Jóźwiak S. , Durejko T.

Biuletyn Wojskowej Akademii Technicznej

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2003

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tom Vol. 52, nr 11

35-47

PL

W pracy przedstawiono wyniki badań stopu na bazie fazy Ni₃Al, z dodatkami stopowymi cyrkonu i boru. Zoptymalizowane parametry obróbki plastycznej i cieplnej pozwoliły na uzyskanie w potencjalnie kruchym stopie poziomu umocnienia wystarczającego do inicjacji procesów aktywowanych cieplnie. W wyniku rekrystalizacji prowadzonej przy precyzyjnie dobranych parametrach uzyskano drobnoziarnistą strukturę osnowy (1000-krotne rozdrobnienie ziarna od stanu pierwotnego w postaci krystalitów o wymiarach liniowych do 4 mm, od stanu po obróbce w postaci równoosiowych ziaren o średnicy rzędu 4 µm). Dla tak uzyskanego stopu drobnoziarnistego (po wieloetapowej obróbce cieplnej i plastycznej) przeprowadzono skuteczną próbę podwyższenia właściwości wytrzymałościowych (Re, Rm) poprzez dalsze umocnienie plastyczne, uzyskując w skrajnych przypadkach umocnienia Re rzędu 2200 MPa, przy Rm rzędu 2300 MPa i mierzalnym wydłużeniu względnym do 1,5% (wyniki rozciągania w temperaturze pokojowej, w atmosferze powietrza).

EN

The results of study of Ni₃Al phase based intermetallic alloy with zirconium and boron addition are presented. Optimized parameters of plastic working and thermal treatment enabled to achieve the strengthening level sufficient to initiate the thermally activated processes. As a result of recrystalization a fine grain structure of matrix has been obtained (the grain size has been reduced, from 4 mm to 4 µm in diameter). Following this and after multistep thermal and plastic treatment, the material strength has been improved throughout plastic strengthening obtaining Re of the order 2200 MPa and Rm of the order 2300 MPa and relative elongation up to 1.5% (the tensile testing results at room temperature in air atmosphere).

15

Effect of TiC and BN nanoparticles on mechanical and microstructural characteristics of Al7085 hybrid nanocomposites

58%

Garapati P. K. , Dumpala L. , Rao Y. S. R.

Composites Theory and Practice

|

2024

|

tom R. 24, nr 1

57--64

EN

This study regards investigations of the mechanical properties of aluminum 7085/TiC/BN hybrid metal matrix nanocomposites (HMMNCs). The ultrasonic assisted stir casting (UASC) route was used to manufacture the Al7085 HMMNCs by varying the wt.% of titanium carbide (TiC) and boron nitride (BN) (0.0, 0.5, 1.0, 1.5, and 2.0). By means of scanning electron microscopy (SEM) it was observed that the nanoparticles are evenly distributed in the nanocomposites. Additionally, the EDS and XRD results indicate that there were no signs of oxide formations, secondary phases, or impurities in the nanocomposites. The yield tensile strength (YTS), ultimate tensile strength (UTS) and microhardness of the nanocomposites improved with increases in the wt.% of TiC and BN particles up to 1.5, and thereafter decreased. The % elongation of the nanocomposites was reduced and the density of the nanocomposites improved with the addition of TiC and BN nanoparticles.

16

Zastosowanie metod sztucznej inteligencji do predykcji własności produktów hutniczych ze stali konstrukcyjnych

58%

Dobrzański L. A. , Kowalski M. , Madejski J.

Hutnik, Wiadomości Hutnicze

|

2005

|

tom Vol. 72, nr 3

155--162

PL

W pracy opisano sposób predykcji wytrzymałości na rozciąganie oraz granicy plastyczności stali, z wykorzystaniem narzędzi sztucznej inteligencji. Opracowane modele wykorzystujące sztuczne sieci neuronowe wykorzystano następnie do opracowania symulatora, pozwalającego na obserwację analizowanych własności stali, przy ciągłej zmianie składu chemicznego oraz parametrów technologicznych produkcji stali. Wykorzystano również algorytmy genetyczne dla doboru składu chemicznego stali zapewniającego minimalizację ryzyka wytwarzania produktów nie spełniających założonych wymagań.

EN

The paper presents the new method for forecasting the yield point and the ultimate tensile strength for steel using the artificial intelligence tools. The developed models, using the artificial neural networks were used next for developing the simulator making itpossible to visualise the analysed properties of steel at the continuous changes ofits chemical composition and technological parameters of steel production. Genetic algorithms were also used for selection of the steel chemical composition, ensuring minimisation ofthe risk of manufacturing products that would not meet the requirements.

17

Effect of flux composition on the percentage elongation and tensile strength of welds in submerged arc welding

58%

Singh B. , Khan Z. A. , Siddiquee A. N. , Maheswari S. , Sharma S. K.

Archive of Mechanical Engineering

|

2016

|

tom Vol. LXIII, nr 3

337--354

EN

This experimental study reveals the effects of CaF2, FeMn and NiO additions to the base fluxes on tensile strength and percentage elongation of the weld metal. The aim of this study is to develop suitable flux for mild steel for high tensile strength, impact strength and ductility. Bead on plate welds were made using submerged arc welding process. Mathematical model for percentage elongation and UTS of mild steel welds were made. The elements transfer to the welds have been correlated with the above mechanical performance characteristics. The effect of oxygen content on weld elongation and UTS also has been deduced. This study shows that CaF2 and NiO are the significant factors for tensile strength while FeMn is not significant for tensile strength. However, for elongation besides CaF2, the interaction of CaF2 and FeMn was also found significant. The effects of basicity index of the flux and carbon equivalent of the welds on tensile strength and percentage elongation of the welds have also been evaluated.

PL

W studium eksperymentalnym, przedstawionym w pracy, pokazano wpływ domieszek CaF2, FeMn i NiO do podstawowego składu topnika na wytrzymałość na rozciąganie i procentowe wydłużenie metalu spawu. Celem studium było opracowanie topnika odpowiedniego dla stali niskowęglowej, który zapewnia wysoką wytrzymałość na rozciąganie, wytrzymałość na udary i plastyczność. Ściegi spawów wykonano metodą spawania łukiem krytym. Opracowano model matematyczny wydłużenia procentowego i wytrzymałości na rozciąganie (UTS) dla spawów ze stali niskowęglowej. Zbadano korelację między wymienionymi charakterystykami mechanicznymi a transferem pierwiastków do spawu. Wyznaczono także wpływ zawartości tlenu na wydłużenie spawu i ostateczną wytrzymałość na rozciąganie. W badaniach doświadczalnych wykazano, że domieszki CaF2 oraz NiO są istotnymi czynnikami wpływającymi na wytrzymałość na rozciąganie, podczas gdy domieszka FeMn nie ma istotnego wpływu. Oceniono także wpływ współczynnika zasadowości topnika i równoważnika węglowego spawu na wydłużenie procentowe spawu.