scholarly journals The effect of nozzle orifice diameter on penetration depth and mechanical properties of AISI430/AISI1040 dissimilar steel joined by keyhole PTA welding process

2021 ◽  
Vol 51 (04) ◽  
pp. 241-249
Author(s):  
T. TEKER ◽  
N. ÖZDEMIR
2020 ◽  
Vol 993 ◽  
pp. 92-99
Author(s):  
Hao Zhen Guo ◽  
Li Cui ◽  
Hui Huang ◽  
Xiao Guo ◽  
Ding Yong He

This present work explored the welding process of gas metal arc welding for 4mm 5E61 Er-containing aluminum alloy, and then analyzed the microstructure and mechanical properties of the welded joint. The results demonstrated that when the welding current was 160A-220A, the welded joint penetration depth range was 5.75mm to 6.72mm, the melting width ranging from 9.68mm to 11.61mm. When the arc voltage increased from 17.5V to 22.5V, the penetration depth of the welded joint reduced from 6.95mm to 5.57mm, and the melting width ranged from 6.64mm to 11.86mm. When the welding current was 170A, the arc voltage was 17.5V, and the welding speed was 10mm/s. In the third case, a fully penetrated welded joint can be obtained and the joint strength was the highest value. The yield strength reached 192 MPa, the tensile strength can be 301 MPa, and the fracture location occurred in the HAZ. The weld zone of the welded joint mainly consist of the equiaxed dendrites size of 50 μm. The micro-hardness of the weld zone was lower than that of the base metal, and there was no obvious softening phenomenon in the heat affected zone.


2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.


Author(s):  
Josué Rafael Sánchez-Lerma ◽  
Luis Armando Torres-Rico ◽  
Héctor Huerta-Gámez ◽  
Ismael Ruiz-López

This paper proposes the development of the methodology to be carried out for the metal joining process through the GMAW welding process in the Fanuc LR Mate 200iD industrial robot. The parameters or properties were considered for the application to be as efficient as possible, such parameters as speed of application, characteristics of the filler material, gas to be used as welding protection. The GMAW welding process can be applied semiautomatically using a hand gun, in which the electrode is fed by a coil, or an automatic form that includes automated equipment or robots. The advantages and disadvantages of the GMAW welding process applied in a manual and automated way were commented. The mechanical properties of the materials to which said welding can be applied were investigated; The materials with which this type of welding can be worked are the high strength materials, which are used in the automotive industry, for the forming of sheet metal. To know the properties of the material, destructive tests were carried out on the test material to be used, as well as the mechanical properties of the welding.


2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.


2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1249
Author(s):  
Maofu Zhang ◽  
Yanfei Han ◽  
Chuanbao Jia ◽  
Shengfa Dong ◽  
Sergii Maksimov ◽  
...  

In underwater wet welding, the unstable welding process caused by the generation and rupture of bubbles and the chilling effect of water on the welding area result in low quality of welded joints, which makes it difficult to meet the practical application of marine engineering. To improve the process stability and joining quality, a mixture of welding flux with a water glass or epoxy resin was placed on the welding zone before underwater welding. In this paper, welds’ appearance, geometry statistics of welds’ formation, welding process stability, slag structure, microstructure, pores and mechanical properties were investigated. It was found that with the addition of water glass in the mixture, the penetration of weld was effectively increased, and the frequency of arc extinction was reduced. Though the porosity rose to a relatively high level, the joints’ comprehensive mechanical properties were not significantly improved. Notably, the applied epoxy resin completely isolated the surrounding water from the welding area, which greatly improved process stability. Furthermore, it benefited from the microstructure filled with massive acicular ferrite, the average elongation and room temperature impact toughness increased by 178.4%, and 69.1% compared with underwater wet welding, respectively, and the bending angle of the joint reaches to 180°.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 109
Author(s):  
Ateekh Ur Rehman ◽  
Nagumothu Kishore Babu ◽  
Mahesh Kumar Talari ◽  
Yusuf Siraj Usmani ◽  
Hisham Al-Khalefah

In the present study, a friction welding process was adopted to join dissimilar alloys of Ti-Al-4V to Nitinol. The effect of friction welding on the evolution of welded macro and microstructures and their hardnesses and tensile properties were studied and discussed in detail. The macrostructure of Ti-6Al-4V and Nitinol dissimilar joints revealed flash formation on the Ti-6Al-4V side due to a reduction in flow stress at high temperatures during friction welding. The optical microstructures revealed fine grains near the Ti-6Al-4V interface due to dynamic recrystallization and strain hardening effects. In contrast, the area nearer to the nitinol interface did not show any grain refinement. This study reveals that the formation of an intermetallic compound (Ti2Ni) at the weld interface resulted in poor ultimate tensile strength (UTS) and elongation values. All tensile specimens failed at the weld interface due to the formation of intermetallic compounds.


2017 ◽  
Vol 753 ◽  
pp. 305-309 ◽  
Author(s):  
Xu Lu

The welding H-section beam has good mechanical properties with its superior structure. So they become the main components of steel structure and have been widely used. In this paper, the welded H-section beam is used as the research object. The finite element simulation model is established. The heat source parameters are determined. The deformation of the steel due to the welding process is studied. The results show that the bottom plate and the bottom plate inward bending is about 2.32mm cause by welding process. The residual stress can reach 400MPa.


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