Showing papers on "Weldability published in 2022"
TL;DR: In this article , the possibility of underwater wet welding by covered electrode S1300 ultra-high strength steel of different thickness (4 mm and 10 mm) has been investigated, and the visual, metallographic macro- and microscopic tests of samples with two nonparallel beads were performed.
22 citations
TL;DR: In this paper, the possibility of underwater wet welding by covered electrode S1300 ultra-high strength steel of different thickness (4 mm and 10 mm) has been investigated, and it was proved that TBW leads to positive microstructural changes and reduces the number of cracks in different regions of welded joints.
22 citations
TL;DR: In this paper, a 2 mm thick W plate was preheated to 500 ℃ and was successfully welded with pure Cu plate, without any cracks formed in W layer.
12 citations
TL;DR: In this paper , a 2 mm thick W plate was preheated to 500 ℃ and was successfully welded with pure Cu plate, without any cracks formed in W layer.
12 citations
TL;DR: In this paper , a review of dissimilar welding between Inconel and austenitic stainless steel along with its application has been outlined for high-temperature applications and the mechanical and microstructural behavior of this dissimilar joint has been summarized thoroughly in this article.
Abstract:
In this review paper, dissimilar welding between Inconel and austenitic stainless steel along with its application has been outlined for high-temperature applications. The mechanical and microstructural behavior of this dissimilar joint has been summarized thoroughly in this article. Dissimilar welding of Inconel alloys and stainless steel (SS) has massive demand in high temperature and high corrosive applications industries. Austenitic stainless steel contains 16-26% of Cr and 6-12% of Ni elements showing FCC structures have good weldability and high corrosion resistance. Austenitic stainless steel such as 304, 316l, 304H, etc., containing austenite microstructure used in high-temperature applications like power plants, heat exchangers, heating elements, aircraft, and others. In addition, Ni-based Inconel alloys show high-temperature strength and corrosion resistance and are frequently used in high-temperature applications. Ni-based Inconel 718 alloy possesses excellent strength, corrosion resistance and creep resistance at high temperatures are frequently used in combustion chambers, power plants and turbine blades ap/plications. Inconel alloyed by elements Ti, Al and Nb attain strength by forming phases such as ?/-Ni3(-Ti, Al), ?//-Ni3Nb, and carbides such as MC and M23C6, nitrides, laves phase. The GTA dissimilar welding between expensive Inconel and cheaper stainless steel is successfully used in nuclear power plants. The dissimilarity in melting point, chemical composition, thermal, mechanical, and other properties between these materials make welding challengeable. This review paper focused on problems related to dissimilar welding like forming unmixed zone, elemental segregation, formation of laves phase, sensitization, microfissuring, and solidification cracking.
10 citations
TL;DR: AISI 304 stainless steels are used to enhance the life of cutting tools, reduce cutting temperature, reduce friction between tool and workpiece, and to improve the machining efficiency and surface integrity as mentioned in this paper .
10 citations
TL;DR: In this paper , the effects of alloy designs on the heat-affected zone softening, microstructure evolution, and the mechanical properties of the weld joints corresponding to different welding techniques and filler wire chemistry are discussed.
Abstract: In recent years, the demand for advanced high-strength steel (AHSS) has increased to improve the durability and service life of steel structures. The development of these steels involves innovative processing technologies and steel alloy design concepts. Joining these steels is predominantly conducted by following fusion welding techniques, such as gas metal arc welding, tungsten inert gas welding, and laser welding. These fusion welding techniques often lead to a loss of mechanical properties due to the weld thermal cycles in the heat-affected zone (HAZ) and the deposited filler wire chemistry. This review paper elucidates the current studies on the state-of-the-art of weldability on AHSS, with ultimate strength levels above 800 MPa. The effects of alloy designs on the HAZ softening, microstructure evolution, and the mechanical properties of the weld joints corresponding to different welding techniques and filler wire chemistry are discussed. More specifically, the fusion welding techniques used for the welding of AHSS were summarized. This review article gives an insight into the issues while selecting a particular fusion welding technique for the welding of AHSS.
9 citations
TL;DR: In this article , the influence of the pulsed Nd:YAG laser welding process on the microstructure and mechanical characteristics of Inconel 718 alloy weldments of 1 mm thin sheets was investigated.
Abstract: ABSTRACT The influence of the pulsed Nd:YAG laser welding process on the microstructure and mechanical characteristics of Inconel 718 alloy weldments of 1 mm thin sheets was investigated. By varying the selected input variables such as laser power, weld speed, and pulse duration, an analysis has been done on the weld characteristics, namely penetration and top and bottom width by Taguchi’s approach. The results were presented by focusing on weld bead geometry, grain structure in the Fusion Zone (FZ), Heat Affected Zone (HAZ), and the tensile properties. The FZ and HAZ microstructure consists of equiaxed, columnar grain structures, respectively, and clear ductile failure was observed with weldment. The combination of laser power at 2.5 kW, weld speed at 2.38 mm/min, and pulse duration at 6.6 ms achieves minimum top and bottom width. Similarly, a combination with 3.3 kW laser power, 2.02 mm/min weld speed, and 8.4 ms pulse duration offers maximum possible penetration that results in quality weldments. The influence of process variables was analyzed by ANOVA. A hybrid Grey–ANFIS model is evolved for determining the multiple performance index. From the validation outcomes attained (MAPE – 0.0413, correlation coefficient – 0.9991), it is proved that the evolved model is proficient for precise prediction.
9 citations
TL;DR: In this paper , the weldability of 10 mm thick 316 L stainless steel plates used in the production of LNG tanks by gas tungsten arc welding was investigated, where optical microscopy and scanning electron microscopy as well as energy dispersive spectroscopy were employed to investigate the microstructural evolution in the weld region of the joint fabricated.
8 citations
TL;DR: In this article , the microstructure and the mechanical properties of the welding joints were studied by optical microscope (OM)，scanning electron microscope (SEM), transmission electron microscopy (TEM), hardness test and tensile test.
Abstract: Al-Mg-Sc, Al-Si-Sc and Al-Zn-Mg-Cu-Ti/TiB2 alloy welding wires are prepared to evaluate their weldability toward the high strength 7075 aluminum alloy. The microstructure and the mechanical properties of the welding joints were studied by optical microscope (OM)，scanning electron microscope (SEM), transmission electron microscope (TEM), hardness test and tensile test. The results showed that the welding wires of Al-Si-Sc alloy and Al-Zn-Mg-Cu-Ti/TiB2 alloy exhibit good weldability, while that of Al-Mg-Sc alloy is of relatively poor weldability due to the existence of hot cracks. The welding joint using Al-Zn-Mg-Cu-Ti/TiB2 alloy welding wire has the highest ultimate strength of 300 MPa, while the ultimate strength of the welding joints using Al-Mg-Sc and Al-Si-Sc alloy welding wires are 200 MPa and 144 MPa, respectively. The weld zone formed by Al-Zn-Mg-Cu-Ti/TiB2 alloy welding wire consists of fine equiaxed grains with sizes around 15 µm, which are associated with the modification of the Al3Ti and TiB2 particles. The low-cost Al-Zn-Mg-Cu-Ti/TiB2 alloy welding wire has good application potential in the welding of 7000 series ultra-high strength aluminum alloy, due to its excellent weldability and good mechanical properties.
TL;DR: In this article, a standard dry sliding wear test was conducted on wire arc additive manufacturing (WAAM) specimens to examine wear behavior. And the results showed that the nickel-based WAAMed alloy had an equiaxed dendritic structure, whereas the wrought alloy had a cellulose structure.
Abstract: Abstract Wire arc additive manufacturing (WAAM) is a low-cost method of fabricating large components from advanced materials such as nickel-based superalloys. Nickel-based superalloys have varied industrial applications and suit the WAAM method due to their excellent weldability when used in conjunction with metal inert gas welding equipment used in the current study. All WAAM specimens were subjected to a standard dry sliding wear test to examine wear behavior. During the wear study, load, sliding velocity, and sliding distance were all considered for both wrought and WAAM alloy. The lowest wear was observed at a lower load and higher sliding velocity, whereas the highest wear was observed at a higher load and lower sliding velocity. Wear mechanisms and wear debris corresponding to lowest and highest wear conditions were also investigated. The transition from lowest to highest wear rate in both alloys was attributed to the transition from abrasive to adhesive and delamination wear mechanisms. Microstructural analysis revealed that the nickel-based WAAMed alloy had an equiaxed dendritic structure, whereas the nickel-based wrought alloy had a cellulose structure. Both specimens had a stable austenite structure in the Ni-Fe-Cr phase, as determined by X-ray diffraction analysis. The X-ray diffraction line profile analysis technique by the Williamson-Hall relationship revealed that WAAM alloys have higher microstrain, higher dislocation density, and smaller crystallite size when compared to wrought alloys. The experimental results showed a 23% increase in hardness and a considerable improvement in wear resistance in the WAAMed alloy compared to the wrought alloy. Graphical Abstract
TL;DR: In this article , the authors investigated the gas tungsten arc weldability of the high-entropy alloy CoCrFeMnNi with and without fillers and showed that the Cu-rich phase formed in the CuCrFMnNi-based weld enhanced its tensile properties.
TL;DR: In this paper, the effects of alloying element on microstructural characterization and mechanical properties of the joints were investigated, and the results showed that laser welding of TiAl/Ni-based superalloy was not achieved by using Ti filler metal.
Abstract: Dissimilar welding of TiAl-based alloy and Ni-based superalloy with different single alloying element (Ti, Nb, V, Cu) was performed by laser. Detailed effects of alloying element on microstructural characterization and mechanical properties of the joints were investigated. The results showed that laser welding of TiAl/Ni-based superalloy was not achieved by using Ti filler metal. The large number of Ni0.35Al0.30Ti0.35 brittle phases in the joint was the main factor of affecting the weldability of joint. Laser welding was not achieved a better connection by using Nb filler metal, and macrocracks existed in the weld, which mainly attributed to the formation of AlNbNi, AlNbNi2 and Cr2Nb intermetallics. The dissimilar metals was successfully welded by using V filler metal, and (V,Cr) solid solution and (V,Cr)/AlNi2Ti eutectic phase were formed in the weld zone. The average tensile strength of the joint was 140 MPa and the joint fracture occurred on Ni-based superalloy side, owing to the fine (V,Cr)/AlNi2Ti eutectic phase. The dissimilar metals was successfully welded by using Cu filler metal, and Cu solid solution and Al(Ni,Cu)2Ti/Cr eutectic phase were formed in the weld zone. The average tensile strength of the joint was 155 MPa and the joint fracture occurred on TiAl alloy side where more AlCuTi and AlCu2Ti formation has.
TL;DR: In this paper , the advantages and difficulties in the application of rare earth (RE) oxide metallurgy technology are analyzed, combined with the performance mechanism of RE and its formation characteristics of fine and high melting point RE inclusions with distribution dispersed in liquid steel.
Abstract: Oxide metallurgy technology plays an important role in inclusion control and is also applied to improve the weldability of high strength steel. Based on the requirements of the weldability in high strength steel, the influencing factors of weld heat affected zone (HAZ) as well as the development and application status of oxide metallurgy technology are summarized in this review. Moreover, the advantages and difficulties in the application of rare earth (RE) oxide metallurgy technology are analyzed, combined with the performance mechanism of RE and its formation characteristics of fine and high melting point RE inclusions with distribution dispersed in liquid steel. With the weldability diversities of different high strength steels, the research status of weldability of high strength steel with high carbon equivalent and the effects of RE on the microstructure and properties of HAZ are discussed, and some suggestions about further research in the future are proposed.
TL;DR: In this article , the weldability of aerospace grade Al-Cu-Li alloy AA2065 by wire-based laser metal deposition (LMD) by using a self-produced wire was evaluated by producing single tracks on a base plate.
Abstract: Al-Cu-Li alloys exhibit a superior strength to weight ratio, making the alloys attractive for applications within aviation and aerospace. However, their widespread application has been somewhat limited by the challenges associated with porosity and crack formation during welding. The purpose of this study was to evaluate the weldability of aerospace grade Al-Cu-Li alloy AA2065 by wire-based Laser Metal Deposition (LMD) by using a self-produced wire. The influence of selected process parameters on deposition geometry (width, height and deposition depth), porosity, microstructure and hardness were evaluated by producing single tracks on a base plate. Defect-free tracks with minimal porosity could be produced with a laser power of 2700 W, 800 μm spot size and 1 m/min scanning speed, providing an energy density of 5.4 J/mm2. Depending on the desired deposition rate, the wire-feed rate could be varied between 1 and 1.9 m/min. The microstructure of the deposited material consisted of columnar and globular equiaxed grains with a Cu-rich second phase network throughout the deposited material. The results presented in this study show the potential in utilizing wires produced of AA2065 for laser welding and potentially additive manufacturing by wire-based LMD, increasing the possible areas of application for such high-strength, low weight alloys.
TL;DR: In this article , the expansion of friction stir welding (FSW) in parts made via material extrusion (MEX) 3D printing was investigated, where poly(methyl methacrylate) (PMMA) plates were joined in full factorial experimental design.
Abstract: In this work, the expansion of friction stir welding (FSW) in parts made via material extrusion (MEX) 3D printing was investigated. Poly(methyl methacrylate) (PMMA) plates were joined in a full factorial experimental design. The effects of three FSW parameters (weld tool pin geometry, rotating speed, and travel speed) on the weld results were studied. The tensile strength was investigated using statistical modeling tools. A morphological characterization study was also conducted on the weld zone, with microscopy. The state of the material during the FSW process was monitored via real-time temperature measurements. The feasibility of the process was verified. The results show high industrial merit for the process. The highest tensile strength was reported for the sample welded with the frustum tool, at 1400 rpm and a 9 mm/min travel speed (the highest studied), with a welding efficiency > 1. This can be attributed to the reduced porosity of the weld area compared to the 3D printed structure, and indicates a high potential for joining 3D-printed PMMA sheets via the FSW process.
TL;DR: In this paper , the role of welding parameters, LPBF scan strategy and post heat treatment on the weld bead formation has been studied by means of microstructural and mechanical characterization, and the results showed that a higher welding speed reduces the porosity in the bead obtaining values of about 5% in terms of percentage of fused area, while the post-heat treatment has the greatest influence on the final properties of the joint compared to the scanning strategy used.
TL;DR: In this article , an ultralight Mg-14Li-1Al (LA141) alloy plate having a thickness of 2 mm was successfully joined by friction stir welding (FSW).
TL;DR: In this article , Ni interlayer was employed during the resistance spot welding (RSW) of 2-mm-thick 630 martensitic stainless steel (MSS), and the microstructures of the joints with and without Ni addition were characterized using optical microscopy and EBSD analysis.
TL;DR: In this paper , the optimal parameters for the weldability window of pure titanium and a new duplex stainless steel (TP 270C/SUS 821L1) were explored, particularly the lower and left limits.
Abstract: In this study, the optimal parameters for the weldability window of pure titanium and a new duplex stainless steel (TP 270C/SUS 821L1) were explored, particularly the lower and left limits. A series of experiments were conducted, and the details of physical quantities during welding, such as the jet, pressure, and melting, were obtained via the smooth particle hydrodynamics (SPH) method. The simulation results demonstrated how these physical quantities changed with the welding parameters near the lower and left limits. The lower limit was determined according to experimental and simulation results, while the left limit was determined according to experimental findings. Via simulation, it was found that the jet and left limit are related to the ratio of the pressure and tensile strength (P/σb). The experimental results provided new notions regarding the left limit. Through the weldability window analysis. The optimal parameters of explosive welding should be slightly above the lower limit; an area near the left limit also offered optimal parameters for welding.
TL;DR: In this paper , dissimilar butt joints were produced from AA5083 and AA6060 alloys and a constant tool traverse speed of 100 mm/min and a tool tilt angle of 2º were used, combined with tool rotational speeds of 800, 1000 and 1200 RPM.
Abstract: Aluminum alloys have been successfully used in the railroad and automotive industries because of their potential to significantly reduce component weights, and their good mechanical and anti-corrosion properties. Problems with joining aluminum alloys are characterized by low weldability, which influences the need for studies focused on unconventional methods. The environmentally friendly and low-cost friction-stir-welding method enables the material to be joined without melting. In the following study, dissimilar butt joints were produced from AA5083 and AA6060 alloys. A constant tool traverse speed of 100 mm/min and a tool tilt angle of 2º were used, combined with tool rotational speeds of 800, 1000 and 1200 RPM. It was revealed that as the tool speed increases, the hardness in the weld nugget zone increases, due to higher heat input and more effective recrystallization. The highest hardness of the weld nugget zone was observed for the weld that was produced with the highest tool rotational speed, and was equal to 1.07 GPa, compared to the hardness of both parent materials of 0.75 and 1.15 GPa for AA5083 and AA6060, respectively. Increasing the heat input also decreased the hardness of the heat-affected zone, where recrystallization was not observed. The lowest density of dislocations with the highest mobility was observed in the heat-affected zone on the AA6060 side, which also contributed to the reduction in strength in this zone. The produced welds exhibited corrosion resistance between both parent materials, with the lowest corrosion current density being 6.935 ± 0.199 µA·cm–2 for the weld that was produced at a tool speed of 1200 RPM.
TL;DR: In this article , electron beam welding (EBW) joints consist of a supersaturated f.c. matrix with coarse, asymmetric columnar grains (17.7-24 μm), and the contribution of the L12 nanoparticles and Hall-Petch strengthening to the yield strength were estimated to be 537-573 MPa and 105-123 MPa, respectively.
TL;DR: In this paper , the authors investigated the gas tungsten arc weldability of cold-rolled CoCrFeMnNi high-entropy alloys using Cu-coated HEA filler, specifically through the application of various post-weld heat treatment (PWHT) temperatures.
Abstract: This study investigated the gas tungsten arc (GTA) weldability of cold-rolled CoCrFeMnNi high-entropy alloys (HEAs) using Cu-coated HEA filler, specifically through the application of various post–weld heat treatment (PWHT) temperatures. The GTA weldability of cold-rolled HEA was evaluated by applying the optimum condition of full penetration, and the effect of PWHT was investigated in the temperature range of 973–1173 K. No macro-defects were detected in the weld metal (WM) to which the Cu coated HEA filler was applied. All the PWHT-applied specimens, including the as-welded specimens, were composed of the FCC phase. The Cu component was solid-solutionized over the entire area of the WM and did not form a precipitate. The tensile properties of the as-welded specimens deteriorated in the presence of CrMn oxides. As the PWHT temperature increased, the grain size in the base metal (BM) increased and inclusions in the WM were re-dissolved. Furthermore, by increasing the PWHT temperature, the hardness of the BM decreased significantly by grain growth, and the WM softened slightly owing to the re-dissolution of inclusions. Therefore, the WMs improved the tensile strength and elongation with increasing PWHT temperature. The application of PWHT significantly improved the weldability of the Cu coated CoCrFeMnNi welds.
TL;DR: In this article , a ternary zinc-aluminum-magnesium (TZ-Mg)-coated steel was brazed to AA 6061 aluminum alloy by laser brazing using an Al-Zn filler material.
TL;DR: In this paper , the results from the Grey relational analysis revealed the optimal parameter combination as voltage 45 kV, beam current 25 mA, welding speed 1.2 m/min.
01 Sep 2022-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper , the influence of a wide range of major build parameters on microstructures and mechanical properties of 718 Ni alloys was explored, and a threshold energy density was identified below which the properties of the additively manufactured specimen degrade substantially.
Abstract: The 718 Ni-based superalloy has gained enormous attention in the additive manufacturing community for its great weldability, allowing for complex geometries to be formed, and its superb mechanical strength. Here we explore the influence of a wide range of major build parameters on microstructures and mechanical properties of 718 Ni alloys. Volumetric energy density appears to be one of the major parameters that captures the relationship between energy input and measured mechanical properties and microstructures of the alloys. A threshold energy density was identified below which the properties of the additively manufactured specimen degrade substantially. The influence of energy density on the quality of the built specimen simulated using Flow3D AM correlates well with the experimental results.