scholarly journals Coupling between Welding Conditions and Thermal Cycling for Identification of the Mechanical Heterogeneity of a Weld Joint

2018 ◽  
Vol 62 (3) ◽  
pp. 226-232
Author(s):  
Fatima Zohra Messabih ◽  
Benattou Bouchouicha
Keyword(s):  
Weld Joint ◽  
Low Temperatures ◽  
Thermal Cycle ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Transition Curve ◽  
Mechanical Heterogeneity ◽  
Break Junctions ◽  
Brittle Transition ◽  
Strength Tests

The analyses device safety subject to pressure is based on the prediction at break junctions used for the design of this type of devices. The harmfulness analysis of existing defects on these devices makes indispensable the study of the rupture in these components. Various characterization tests (tensile tests, fatigue tests and tensile strength tests) were carried out at room and low temperatures on plates welded end to end and for the different directions of sampling.An estimate of the toughness in the three areas of a weld joint was made by passing from resilience to toughness in the ductile-brittle transition zone of materials. The temperature range of the tests was to provide measurements of the toughness the lower bearing to the beginning of the transition curve. The purpose of this work is to study the state both mechanical and microstructural aspects of the welded junction. The diagnoses used made it possible to deduce that the small thickness of the HAZ, makes the machining of the specimen difficult. Thereby, a mechanical simulation of the HAZ by registration of the thermal cycle that this area undergoes was necessary to be able to reproduce it and compare it with the actual HAZ.

Static and Cyclic Behavior of Welded DH36 Steel and Its Application at Low Temperatures

2021 ◽  
pp. 1-31
Author(s):  
Weidong Zhao ◽  
Guoqing Feng ◽  
Bernt J. Leira ◽  
Huilong Ren
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
Fatigue Tests ◽  
Cyclic Behavior ◽  
Brittle Transition ◽  
Ductile To Brittle Transition

Abstract The mechanical properties of welded DH36 steel at low temperatures are important to the safety of structures in Polar areas. The purpose of the study is to investigate the static and cyclic behavior of welded DH36 steel at low temperatures based on tensile and fatigue tests. The Ductile to Brittle transition and Fatigue Ductile to Brittle Transition of welded DH36 steel occurred at low temperatures. Finally, some relevant applications of the results within the context of polar engineering and design are discussed in the last part of the present study.

scholarly journals Investigations on arc brazing for galvanized heavy steel plates in steel and shipbuilding

2021 ◽  
Author(s):  
Philipp Andreazza ◽  
Andreas Gericke ◽  
Knuth-Michael Henkel
Keyword(s):  
Low Cost ◽  
Thin Sheet ◽  
Steel Structures ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Steel Plates ◽  
Galvanized Steel ◽  
Filler Materials ◽  
Static Tensile ◽  
Brazed Joints

AbstractArc brazing with low-melting copper-based filler materials, which has long been established and standardized in the thin sheet sector, offers numerous advantages in the processing of predominantly electrolytically galvanized steel structures. In steel and shipbuilding, on the other hand, equipment parts made of thick steel sheets are hot-dip galvanized at low cost and with good corrosion-inhibiting properties. Quality welding of such constructions is not possible without special precautions such as removing the zinc layer and subsequent recoating. With regard to greater plate thicknesses, arc brazing was analyzed in these investigations as an alternative joining method with regard to its suitability for practical use. Within the scope of the investigations, CuSi3Mn, CuMn12Ni2, and four different aluminum bronzes were examined on different sheet surface conditions with regard to the geometrical and production parameters. This was carried out by build-up and connection brazing, executed as butt and cross joints. Quasi-static tensile tests and fatigue tests were used to assess the strength behavior. In addition, metallographic analyses are carried out as well as hardness tests. The suitability for multi-layer brazing and the tendency to distortion were also investigated, as well as the behavior of arc brazed joints under corrosive conditions.

Apparatus for fatigue tests in vacuum at low temperatures

1974 ◽  
Vol 45 (5) ◽  
pp. 702-704 ◽  
Author(s):  
V. Bachmann ◽  
M. Böhmer ◽  
D. Munz
Keyword(s):  
Low Temperatures ◽  
Fatigue Tests

scholarly journals Changing in Fatigue Life of 300 M Bainitic Steel After Laser Carburizing and Plasma Nitriding

2018 ◽  
Vol 165 ◽  
pp. 21002 ◽  
Author(s):  
Antonio J. Abdalla ◽  
Douglas Santos ◽  
Getúlio Vasconcelos ◽  
Vladimir H. Baggio-Scheid ◽  
Deivid F. Silva
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Plasma Nitriding ◽  
Fatigue Behavior ◽  
High Strength ◽  
Tensile Tests ◽  
Steel Sample ◽  
Fatigue Tests ◽  
300M Steel ◽  
Structural Applications

In this work 300M steel samples is used. This high-strength steel is used in aeronautic and aerospace industry and other structural applications. Initially the 300 M steel sample was submitted to a heat treatment to obtain a bainític structure. It was heated at 850 °C for 30 minutes and after that, cooled at 300 °C for 60 minutes. Afterwards two types of surface treatments have been employed: (a) using low-power laser CO2 (125 W) for introducing carbon into the surface and (b) plasma nitriding at a temperature of 500° C for 3 hours. After surface treatment, the metallographic preparation was carried out and the observations with optical and electronic microscopy have been made. The analysis of the coating showed an increase in the hardness of layer formed on the surface, mainly, among the nitriding layers. The mechanical properties were analyzed using tensile and fatigue tests. The results showed that the mechanical properties in tensile tests were strongly affected by the bainitic microstructure. The steel that received the nitriding surface by plasma treatment showed better fatigue behavior. The results are very promising because the layer formed on steel surface, in addition to improving the fatigue life, still improves protection against corrosion and wear.

scholarly journals 3D characterization of the fracture mechanisms of a Fe-rich Al-Si-Cu alloy

2018 ◽  
Vol 165 ◽  
pp. 04006
Author(s):  
Angelika Brueckner-Foit ◽  
Inigo Bacaicoa ◽  
Martin Luetje ◽  
Marcel Wicke ◽  
Andreas Geisert ◽  
...  
Keyword(s):  
Crack Initiation ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Fracture Mechanisms ◽  
Crack Advance ◽  
Micro Computed Tomography ◽  
Initiation Mechanism ◽  
Initiation Phase ◽  
Β Phase ◽  
Cu Alloy

The effect of the defect size and morphology on the fatigue damage evolution was analysed in a recycled Al-Si-Cu alloy by micro-computed tomography and scanning electron microscopy. Fatigue tests were performed and the different crack initiation scenarios were characterized and classified. The interaction between shrinkage and gas pores was the key crack initiation mechanism and the ß-Al5FeSi particles did not play any role in the crack initiation phase. However, crack path analysis indicated that there is a certain amount of crack advance by brittle fracture of the β-phase particles. This is in accordance with the findings of tensile tests in which the ductility depended strongly on the iron content.

Evaluation of the Ductile-Brittle Transition Behaviour of Aging Specimens by the Fracture Toughness Test

2006 ◽  
Vol 321-323 ◽  
pp. 536-540
Author(s):  
Hyung Ick Kim ◽  
Yong Huh ◽  
Jae Sil Park ◽  
Chang Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Low Temperatures ◽  
Fracture Toughness Test ◽  
Evaluation Technique ◽  
Brittle Transition ◽  
Ductile Brittle Transition Temperature ◽  
Specimen Test ◽  
Safety And Reliability ◽  
Brittle Transition Temperature ◽  
Transition Behaviour

The safety and reliability of industrial machineries and structures used in various, and severe conditions has become an increasing concern. This study proposes ductile-brittle transition temperature (DBTT) evaluation technique by the sub-sized specimen test to prevent cleavage fracture. Four classes of the thermally aged 1Cr-1Mo-0.25V specimens were prepared. The fracture toughness tests were performed on sub-sized specimens both at room and low temperatures. The results of the fracture toughness tests were analyzed to obtain the DBT behaviours of the specimen materials

Mechanical Properties of Flat Braided Composites With a Circular Hole

1999 ◽  
Author(s):  
Takeru Ohki ◽  
Shinya Ikegaki ◽  
Ken Kurasiki ◽  
Hiroyuki Hamada ◽  
Masaharu Iwamoto
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Circular Hole ◽  
Fracture Behavior ◽  
Fatigue Property ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Braided Composites ◽  
Static Tensile ◽  
The One

Abstract In this study, fracture behavior and strength in the flat braided bar with a circular hole were investigated by static and fatigue test. Two type of specimens were prepared. They are a braided flat bar with an integrally-formed braided hole and a braided flat bar with a machined hole. Moreover, we also examined a specimen that had a metal pin inserted at the circular hole. This specimen was subjected to a static tensile test. The results of the tensile tests indicate that the strength of the flat bar with a braided hole was larger than that of the one with the machined hole. Furthermore, from the results of the fatigue tests, the flat bar with the braided hole showed higher fatigue property than that of the one with the machined hole.

Fatigue Properties of 3D Welded Thin Structures

2020 ◽  
Author(s):  
Seyed M. Allameh ◽  
Avery Lenihan ◽  
Roger Miller ◽  
Hadi Allameh
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Fatigue Testing ◽  
Interfacial Area ◽  
Tensile Tests ◽  
Orientation Dependence ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Mig Welding ◽  
Welded Structures

Abstract Additive manufacturing technology has matured enough to produce real industrial components. A newer method of 3D printing is the deposition of molten metal beads using a MIG weld torch. This involves a 3D printer equipped with a MIG torch layering the metals in desired shapes. It allows the fabrication of components made of MIG weld wires, currently available from various elements including Cu, Al, steel and alloys. Some of these structures made by 3D welding will have applications in critical load bearing conditions. The reliability of such components will be vital in applications where human lives are at stake. Tensile tests are conducted to verify the required strength of the fabricated parts which will undergo monotonic loading; however, fatigue tests are required for cases where cyclic loading will take place. Conventional tensile and fatigue testing requires macro-scale samples. With MIG welding, it is possible to make thin-walled structures. Fatigue testing on samples extracted from thin walls is made possible by microtesting. This study is focused on the mechanical properties of 3D welded structures made from MIG welding wires. Our earlier results showed orientation dependence of mechanical properties in 3D welded structures. They also showed the effect of substrates in expression of the orientation dependence. Welding on metal substrate produces weld beads that are harder at the substrate interfacial area. However, for structures welded on ceramics, the opposite is true. They exhibit a softer substrate interfacial area and a relatively harder top. Our newer results show fatigue properties of structures made by 3D welding. Microsamples measuring 0.2 mm × 0.2 mm × 1.0 mm were extracted from metal beads using a CNC mill along with an EDM. The contours of the samples were machined by milling and the back side was cut by electro discharge machining. Specimens were then polished to the desired size and mounted in the grippers of an E1000 Instron load frame. WaveMatrix® application software from Instron was used to control the machine and to obtain testing data. Fatigue tests were performed, and life cycles were determined for various stress levels up to over 5 million cycles. The preliminary results of tensile tests of these samples show strength levels that are comparable to those of parent metal, in the range of 600–950MPa. Results of fatigue tests show high fatigue lives associated with relatively high stresses. The preliminary results will be presented and the implications of the use of 3D welded rebar in 3D printing of reinforced concrete structures will be discussed.

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