Wyniki wyszukiwania - BazTech

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Bead-on-Plate Underwater Wet Welding on S700MC Steel

Tomków Jacek, Świerczyńska Aleksandra, Landowski Michał, Wolski Adrian, Rogalski Grzegorz

Advances in Science and Technology. Research Journal

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2021

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Vol. 15, no 3

288-296

EN

The participation of high strength steels in marine and offshore structures is increasing, which makes it necessary to develop recommendations for underwater repair welding works. The article presents the results of bead-on-plate welded specimens made of S700MC high strength steel in underwater wet welding conditions by covered electrodes. Three specimens with heat input values in the range 0.91-1.05 kJ/mm were made. The specimens were subjected to visual, metallographic, macro- and microscopic tests as well as hardness measurements using the Vickers method. It was found that the higher heat input leads to formation of mixed bainite-martensite microstructure in the heat-affected zone (HAZ). Lower heat input value results in presence of martensite in HAZ. It was shown that in the scope of the performed tests, the maximum hardness of HAZ did not exceed the critical value for the material group, and the increase in heat input caused the decrease of hardness by about 25 HV10.

2

The influence of currant mma welding on the tensile strenght of joint

Penkała P., Płowaś B

Advances in Science and Technology. Research Journal

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2014

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Vol. 8, nr 21

43--48

EN

Welding with coated electrodes is still growing method of joining metals in construction machinery. If the electrodes are properly selected and current welding can weld materials in a wide range of geometric dimensions and species. With carefully selected ingredients one can introduce additional elements to the welded material and the joint during welding. An important issue in the electric welding is a welding current selection, depending on the thickness of the electrode and material thickness. The use of too low operating current cause instability and inadequate mechanical properties of the weld, resulting from insufficient melting of the material combined. Too high operating current results in the weld metal spraying and thermal overload of the electrode. For welding samples that were used to test the strength of the electrode used ESAB OK. 46.00 a diameter of 3.2 mm. Product of the company will provide a range of welding current ranging from 80 A to 150 A. The samples were welded currents amounting to 90 A, 115 A and 150 A. Due to problems with arc ignition and its instability is not made of welded samples current of 80 A.

3

Welding of girders to insert plates of composite steel-concrete structure

Klimpel A., Lisiecki A., Szlek J.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

397-404

EN

Purpose: of this paper: A study of influence of preheating and MMA welding technique of tee-joints of plate girders to insert plates of a composite steel-concrete structure of the telecommunication tower, on the properties and quality of the concrete in the region of the insert plate has been carried out. Design/methodology/approach: Studies of thermo-mechanical phenomena during manual arc welding MMA of tee-joints between plate girders and insert plates were carried out to identify possible sources of the concrete damage due to high welding temperature and stresses. Findings: It was shown that MMA welding at vertical-up position, by a rutile coated electrode of diameter 3,2 [mm], at welding current 110-120 [A], of the butt welds of tee-joints of girders and the insert plate does not cause any harmful and damaging effect to concrete, which temperature in a region of the contact with the bottom surface of the insert plate does not exceed 240 [degrees centigrade] during full cycle of welding. Tensile and compression stresses of concrete are transmitted mainly by anchoring bars, fixed in concrete and also by reinforcing fabric of concrete, and do not cause any cracks of concrete. Research limitations/implications: To achieve more consistent results of the numerical analysis of stresses and deformation distribution in the insert plate with experimental results, it is necessary to calculate plastic deformation of materials and also take into consideration nonlinear change of yield point (plasticity) as a function of temperature. Practical implications: The technology was applied for welding of the girders to insert plates of the telecommunication tower in Kuwait. Originality/value: Welding procedure specification ensuring high quality of the welded joints of girders and insert plate of composite steel-concrete structure.

4

Badania eksperymentalne i przewidywanie wpływu technologii spawania na wytrzymałość zmęczeniową połączeń doczołowych ze stali 18G2A.

Szubryt M., Skorupa M.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2005

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R. 49, nr 2

43-47

PL

Przedstawiono wyniki obliczeń wytrzymałości zmęczeniowej złączy doczołowych ze stali 18G2A z wykorzystaniem zależności Basquina-Marrowa oraz ich weryfikację za pomocą badań eksperymentalnych. Połączenia wykonano trzema metodami spawania: ręcznego elektrodami otulonymi (MMA), zautomatyzowanego w osłonie gazów aktywnych (MAG) i wysokowydajnego w osłonie gazów aktywnych (T.I.M.E.). Głównym celem badań było określenie wpływu technologii spawania ww. metodami na wytrzymałość zmęczeniową połączeń oraz zbadanie, czy zastosowany model matematyczny prawidłowo przewiduje ten wpływ.

EN

A methodology of estimating the fatigue limit of butt joints in 18G2A steel using the Basquin-Morrow equation is presented and the prediction approach is validated through comparisons with the fatigue test results. Three welding processes, namely the manual welding with covered electrodes (MMA), active gas shielded automatic welding (MAG) and the highly efficient welding in active gas shielding (T.I.M.E) have been considered. The main goal of the research was to investigate the effect of the welding process on the fatigue limit of the welds and to check the capability of the theoretical model applied to predict the fatigue limit for the specific process of welding.

5

Nowoczesne źródła prądu i koncepcje sterowania dla wszystkich rodzajów procesów spawania łukiem elektrycznym.

Kaulbach H., Remmel J.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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1999

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R. 43, nr 5

20-25

PL

Wydawało się, że wprowadzenie na rynek w latach osiemdziesiątych elektronicznych, tranzystorowych źródeł prądu spawania wyeliminuje konwencjonalne urządzenia spawalnicze. Jednak tak się nie stało. Nadal produkuje się sterowane tyrystorami urządzenia MIG/MAG oraz urządzenia do spawania elektrodami otulonymi. Taki rozwój sytuacji spowodowały konkretne zadania stawiane urządzeniom oraz ich koszt, a także obawy użytkowników wobec nowoczesnej elektroniki. Elektroniczne transformatorowe źródła prądu zdobyły przewagę w wyjątkowo wymagającym procesie ręcznego spawania TIG lub spawania plazmowego, natomiast w częściowo zmechanizowanych procesach spawania MIG/MAG w głównej mierze są stosowane urządzenia konwencjonalne. Poprzez rozwój techniki cyfrowej i modułowej budowy urządzeń znacznie ułatwiono ich obsługę, polepszono elastyczność urządzeń oraz znacznie uproszczono wymianę danych pomiędzy parametrami procesu spawania a pamięcią i układem sterowania źródła prądu. Rozwój ten z pewnością będzie dalej przebiegał w trzecim tysiącleciu, co spowoduje ciągły proces wypierania konwencjonalnych technik budowy spawalniczych źródeł prądu.

EN

It seemed that the introducing in 1980' electronic, transistorised welding power sources into market would eliminate conventional machines. It did not happen so, however. The manufacture of thyristor-controlled MIG/MAG welding machines, as well as those for MMA welding has been continued. Such a situation has been caused by define tasks imposed on welding equipment and users of modern electronics. Electronic transformer welding power supplies dominate in manual TIG and plasma arc welding processes whereas conventional machines are used to a greater extend in partly mechanised MIG/MAG welding process. Through development of digital electronics and modular construction of machines, their service has been made much easier and the exchange of information about the welding paramters between the power source memory and control system has been made much simpler. This development, unquestionably, will proceed in the third millennium what will cause the permanent supersession of conventional technique of welding power sources construction.

6

Metody badania skłonności spoin do porowatości przy spawaniu elektrodami otulonymi.

Niagaj J.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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1998

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R. 42, nr 6

17-20

PL

Omówiono metody wykrywania pęcherzy i porów w spoinach. Na podstawie danych literaturowych scharakteryzowano metody badania skłonności spoin do porowatości przy spawaniu elektrodami otulonymi. Przedstawiono wyniki badań własnych nad opracowaniem ulepszonej metody badania skłonności spoin do porowatości.

EN

The method of detection of blowholes in weld metal have been discussed. On the basis of professional literature data it has been characterized the methods of examination of weld metal susceptibility to porosity in MMA welding. It has been presented the results of the author's investigations in order to develop an improved method of examination of weld metal susceptibility to porosity.