Wyniki wyszukiwania - BazTech

1

Numerical Modelling of Welding of Car Body Sheets Made of Selected Aluminium Alloys

Wojdat T., Kustroń P., Jaśkiewicz K., Zwierzchowski M., Margielewska A.

Archives of Metallurgy and Materials

|

2019

|

Vol. 64, iss. 4

1403--1409

EN

In the paper, verification of welding process parameters of overlap joints of aluminium alloys EN AW-6082 and EN AW-7075, determined on the grounds of a numerical FEM model and a mathematical model, is presented. A model was prepared in order to determine the range of process parameters, for that the risk of hot crack occurrence during welding the material with limited weldability (EN AW-7075) would be minimum and the joints will meet the quality criteria. Results of metallographic and mechanical examinations of overlap welded joints are presented. Indicated are different destruction mechanisms of overlap and butt joints, as well as significant differences in their tensile strength: 110 to 135 MPa for overlap joints and 258 MPa on average for butt joints.

2

Microstructural Characteristics of Nickel Alloy Grade 600 After High-Temperature Thermal Cycle

Pocica N., Tuz L.

Biuletyn Instytutu Spawalnictwa w Gliwicach

|

2017

|

Vol. 61, No. 6

53--57

EN

The article was a distinguished paper presented at a Symposium of Welding Engineering Institutes and Departments in Istebna on 13-14.06.2017 Abstract: Alloy grade 600 is characterised by high oxidation resistance at high temperature and resistance to stress corrosion. Because of the above-named characteristics, the alloy is widely used in the chemical and food industries as well as in nuclear engineering. However, the alloy belongs to the group of hard-to-weld materials and, because of that fact, has a wide range of a solidification point, which extends the size of the liquid-sensitive fracture area extending beyond the weld pool and occurring in the partially melted zone. The susceptibility of alloys to solidification cracking is determined using high-temperature simulation. The study presents results of tests performed using a Gleeble 3800 simulator. The tests were performed to identify parameters characterising properties of alloy Inconel 600 at high temperature, during heating and cooling, i.e. nil ductility temperature (NDT), nil strength temperature (NST) and ductility recovery temperature (DRT). The identification of the above-named temperatures enabled the determination of the high-temperature brittleness range (HTBR). The material structure in the specimen rupture area was subjected to observation. The specimen fractures were subjected to observation aimed to reveal features revealing fracture types.

PL

Stop 600 charakteryzuje się dużą odpornością na utlenianie w wysokich temperaturach oraz odpornością na korozję naprężeniową. Ze względu na te cechy znalazł szerokie zastosowanie w przemyśle chemicznym, spożywczym, jak również w inżynierii jądrowej. Materiał ten zaliczany jest do grupy materiałów trudno spawalnych. Wynika to z tego, iż posiada szeroki zakres temperatury krzepnięcia, co zwiększa rozmiar obszaru stało-ciekłego wrażliwego na pękanie, który ciągnie się za jeziorkiem spawalniczym i występuje w strefie częściowego stopienia. W celu określenia podatności stopu do występowania pęknięć krystalizacyjnych wykonuje się symulację wysokotemperaturową. W pracy przedstawiono wyniki badań przeprowadzonych na symulatorze Gleeble 3800, mające na celu wyznaczenie parametrów charakteryzujących właściwości stopu Inconel 600 w wysokich temperaturach, podczas nagrzewania i chłodzenia, tj. : temperaturę zerowej plastyczności NDT, temperaturę zerowej wytrzymałości NST i temperaturę odzysku plastyczności DRT. Na podstawie wyznaczonych temperatur określono zakres występowania kruchości wysokotemperaturowej HTBR. Dokonano obserwacji struktury materiału w obszarze zerwania próbki. Ocenie poddano również przełomy próbek, w celu ujawnienia charakterystycznych cech, określających ich rodzaj.

3

Repair of Precision Castings Made of the Inconel 713C Alloy

Łyczkowska K., Adamiec J.

Archives of Foundry Engineering

|

2017

|

Vol. 17, iss. 3

210--216

EN

Inconel 713C precision castings are used as aircraft engine components exposed to high temperatures and the aggressive exhaust gas environment. Industrial experience has shown that precision-cast components of such complexity contain casting defects like microshrinkage, porosity, and cracks. This necessitates the development of repair technologies for castings of this type. This paper presents the results of metallographic examinations of melted areas and clad welds on the Inconel 713C nickel-based superalloy, made by TIG, plasma arc, and laser. The cladding process was carried out on model test plates in order to determine the technological and material-related problems connected with the weldability of Inconel 713C. The studies included analyses of the macro- and microstructure of the clad welds, the base materials, and the heat-affected zones. The results of the structural analyses of the clad welds indicate that Inconel 713C should be classified as a low-weldability material. In the clad welds made by laser, cracks were identified mainly in the heat-affected zone and at the melted zone interface, crystals were formed on partially-melted grains. Cracks of this type were not identified in the clad welds made using the plasma-arc method. It has been concluded that due to the possibility of manual cladding and the absence of welding imperfections, the technology having the greatest potential for application is plasma-arc cladding.

4

CrMoV steel welding in the narrow gap using of SAW technology

Holub L., Dunovský J., Suchánek J.

Journal of Achievements in Materials and Manufacturing Engineering

|

2014

|

Vol. 62, nr 1

31--37

EN

Purpose: of this paper is the verification of multi-layer SAW welding the raw material “1.6946” by different welding consumables (TOPCORE 838 B, Thermatit MTS 616) in the „ultra” narrow gap using the prescribed temperature cycle and subsequent heat treatment. Design/methodology/approach: An evaluation of the mechanical properties of the test for both types welding consumables. The measured values of yield strength and the tensile strength exhibit comparable properties to the RAW material “Inspection Certificate” for welding consumable “TOPCORE 838 B”. Findings: Thermatit MTS 616” was found falling below the specified values of impact energy, ductility. The welding consumable TOPCORE 838 B shows less susceptibility to the brittleness. Based on the results will be verified by the existence of internal structures arising using the microstructure analysis & ARA diagram of the base material 1.6496. Research limitations/implications: Obtained results will be subsequently verified the existence of internal generated microstructures using the ARA chart of the base material (W Nr. 1.6496) for the future design of the new temperature cycles in all phases of the production. Originality/value: The welding consumable “TOPCORE 838 B” showed the low tendency to embrittlement in the heat-affected zone using the defined heat treatment. On the basic of the examination the welding consumable “TOPCORE 838 B” can be recommended to be used for the welding process, thermal cycle and heat treatment.