Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Effect of Interlayer Composition on the Microstructure and Mechanical Properties of 1050 Aluminium to St14 Carbon Steel Joint Via Resistance Spot Welding Method
1
12
FA
H.
Sabet
h-sabet@kiau.ac.ir
Y
0000-0002-8685-8109
R.
Tahavori
Ramin.Tahavvori@kiau.ac.ir
N
0000-0002-3383-02680000-0002-3383-0268
A.
Alimoradi
Alimoradi430@gmail.com
N
Effect of Interlayer Composition on the Microstructure and Mechanical Properties of 1050 Aluminium to St14 Carbon Steel Joint Via Resistance Spot Welding Method.
Resistance Spot Welding, 1050 Aluminium ,St14 Carbon Steel
http://jwsti.iut.ac.ir/article-1-342-en.html
http://jwsti.iut.ac.ir/article-1-342-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Investigation of the effect of explosive welding variables on the corrosion behavior of the joint of two explosive layers of 5000 series copper-copper sheets
13
24
FA
Homan
Nikbakht1
Khanzadeh@yahoo.com
N
0000-0002-0455-8373
Mohammadreza
Khanzadeh
khanzadeh@iaumajlesi.ac.ir
Y
0000-0003-0641-5496
Hamid
Bakhtiari
H.bakhtiari@merc.ac.ir
N
0000-0002-7229-6555
In the present study, the corrosion behavior and microstructural changes of 5000 series aluminum and copper sheets after the explosive welding process have been investigated. Explosive welding is performed with a fixed stop interval and change of explosive load. Dynamic potential polarization tests and electrochemical impedance spectroscopy, light microscopy, and scanning electron microscopy were used. The results of TOEFL polarization curves show that the lowest corrosion velocity was related to the sample with an explosive load of 1.5 and the highest corrosion velocity was related to the sample with an explosive load of 2.5. The corrosion resistance of a sample with an explosive load of 2.5 is less than that of a sample with an explosive load of 1.5 due to more severe plastic deformation at the joint. The metallographic results show a wave-vortexing of the joint due to the increase in the explosive charge. The results of the impedance test in welded samples showed that the value of n (experimental power parameter) decreased with wave-vortexing of the joint and the sample with 2.5 explosive load had the highest corrosion rate. Based on the results of scanning electron microscopy, it was observed that with an increasing explosive charge, the thickness of the local melting layer gradually increases.
Explosive welding, explosive ratio, severe plastic deformation, vortex.
http://jwsti.iut.ac.ir/article-1-377-en.html
http://jwsti.iut.ac.ir/article-1-377-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Joining of the 5083 aluminum alloy using the bobbin tool friction stir welding technique
25
37
FA
N.
Taheri Moghaddam
Islamic Azad University of Shiraz
taherimoghaddamn@gmail.com
N
A.
Rabiezadeh
Islamic Azad University of Shiraz
a.rabiezadeh@gmail.com
Y
0000-0002-7081-8057
A.
Khosravifard
Islamic Azad University of Shiraz
khosravifard@gmail.com
N
L.
Ghalandari
Islamic Azad University of Shiraz
lghalandari@yahoo.com
N
Conventional fusion welding of aluminum alloys results in coarse-grained structure, inevitable defects, and significant softening in the welding region. Friction stir welding with bobbin tool is a technique of friction stir welding method that has a great potential for developing applications of friction stir welding method in marine, aerospace, and automotive industries due to having an extra shoulder. Sheets of 5083 aluminum alloy with a thickness of 3 mm were welded using the bobbin tool friction stir welding method to assess the feasibility of similar joining. The effect of different process variables such as shoulder pinching gap, transverse speed and tool rotation speed was investigated. The results showed that a sound joint is achieved at a transverse speed of 13 mm / min and a tool rotation speed of 1350 rpm. The results of tensile test showed that the obtained joint efficiency is 94.5%, which is higher than the joint efficiency of fusion methods and comparable to the joint efficiency of conventional friction stir welding. Microscopic evaluation of the fracture surface of welded specimens showed that for similar joints, the dominant fracture mechanism is ductile fracture.
Friction stir welding, bobbin tool, aluminum alloy, joint efficiency, microstructure
http://jwsti.iut.ac.ir/article-1-378-en.html
http://jwsti.iut.ac.ir/article-1-378-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Welding of titanium base alloys by tungsten-gas pulse arc process (PCGTAW) and investigation of frequency effect on microstructure and mechanical properties
39
46
FA
Seyed Mahdi
Rafiaei
s.rafiaei@iut.ac.ir
Y
Gholamhosein
Eslami
eslamiali271080@gmail.com
N
In this research, Ti-6Al-4V alloy sheet with a thickness of one millimeter with butt joint design was welded by tungsten-gas arc welding process using pulse current (PCGTAW) and using AMS 4954G filler metal. In this study, the effect of pulse system frequency on microstructure and mechanical properties was investigated by optical microscopy, Vickers hardness and tensile strength tests. In the non-frequency welding sample, due to the lack of pulse current and lower cooling rate of the molten pool, the formation of large amounts of soft phases of the Weidmann-Statten layer in the weld metal region is possible. Finally, in this method, the lowest average hardness of 341 Vickers was obtained. The experimental results showed that using pulsed current and increasing the pulse frequency up to 450 Hz increased the cooling rate of the molten pool, followed by increasing the amount of martensitic phase α 'in the form of a basket in the weld metal region and finally increasing the average microhardness in this region. In other words, using the maximum frequency led to a significant increase in hardness up to 367 Vickers in the weld zone. Finally, using the tensile strength test, it was shown that in all the samples, failure occurred from the base metal area, which was a very good phenomenon due to the proper welding quality of the samples.
Ti6Al4V alloy, Tungsten-gas arc welding (GTAW), Frequency, Pulse current system
http://jwsti.iut.ac.ir/article-1-379-en.html
http://jwsti.iut.ac.ir/article-1-379-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Effect of tool position on microstructural and mechanical properties of friction stir butt welded joint of AA2024–AA7075 dissimilar alloys
47
58
FA
Hosseinn
Soleimani
hosein_sol@yahoo.com
N
Kamran
Amini
kamran_amini1978@hotmail.com
Y
0000-0001-5905-5362
Farhad
Gharavi
drfgharavi@gmail.com
N
In this research, butt joining of Al2024 and Al7075 plates were performed by Friction Stir Welding (FSW) and the effect of tool position on microstructural and mechanical properties in about 1 mm from center line of joint towards the advancing side (AS) and the retreating side (RS) was investigated at three positions of +1, 0, -1 mm. In this regard, the plates of Al2024 and Al7075 were selected as the AS and the RS, respectively. In this joining method, transvers speed of 200 mm/min and tool rotation speed of 600 rpm were chosen. Macro- and Micro- structures of various welding areas and fractography of samples were evaluated by optical and scanning electron microscopies. In addition, mechanical properties were investigated using micro-hardness and tension tests. From the obtained macro-structures, it was observed that in all three joints, the surface of weld was without any defects (i.e., porosity, lack of penetration…). With varying tool offset position, welding micro-structure morphology was changed from homogeneous mode to layer or onion ring- shaped mode. Moreover, with varying tool position into the AS-side, tensile strength increased about 17.5% as opposed to the zero-tool position, but there was a decreasing about in tensile strength with changing tool position towards the RS-side as compared with the zero-tool position. Value of micro-hardness was approximately similar in all welded samples, but the highest value of hardness was observed at the weld zone (WZ). Thus, the obtained results showed that with varying tool position into the AS-side, mechanical properties were improved as opposed to the zero-tool position and tool position towards the RS-side.
Friction Stir Welding, Tool offset, Dissimilar joint, Mechanical properties, Micro-structure
http://jwsti.iut.ac.ir/article-1-371-en.html
http://jwsti.iut.ac.ir/article-1-371-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Optimization of TIG repair welding process parameters to obtain maximum tensile strength in AZ91C magnesium alloy
59
72
FA
Majid
Aslani
emajid2020@gmail.com
N
Mahdi
Rafiei
rafiei_mahdi@yahoo.com
Y
0000-0003-2201-625X
In this study, in order to modify the weld structure obtained from repair welding of AZ91C magnesium alloy and improvement of tensile strength, input parameters such as current intensity and preheating temperature were optimized for this alloy. T6 heat treatment was separately done befor and after the welding to homogenize the microstructure and improvement of the mentioned properties. Using variance analysis, the accuracy of the models was checked and analyzed. Optical microscopy, scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS) and tensile tests were used to characterize the microstructure and mechanical properties of the repaired parts. The results of microstructural studies showed that the samples 2 (samples that were subjected to T6 heat treatment before and after welding) had continuous precipitates which these precipitates affected the strength due to the interruption of more slip planes and creating stronger barriers in the path of dislocations, resulting the better mechanical properties as compared with samples 1 (samples that were subjected to heat treatment only after welding). Also, by plotting response surface graphs and level diagrams, the highest tensile strength for samples 1 was observed at preheating temperatures of 493 to 513 K and current intensities of 80 to 90 A, and for samples 2 at temperatures of 513 to 553 K and current intensities of 100 to 110 A.
Repair welding, TIG, AZ91C, Tensile strength, Design of experiment.
http://jwsti.iut.ac.ir/article-1-381-en.html
http://jwsti.iut.ac.ir/article-1-381-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Effect of bonding temperature on the microstructure and electrochemical corrosion behavior of TLP bonded AISI 304L stainless steel
73
87
FA
Behzad
Binesh
University of Bonab
b.binesh@ubonab.ac.ir
Y
0000-0001-9112-9106
Sima
Mirzaei
Sharif Branch of ACECR
S_mirzaei1@yahoo.com
N
Amin
Taghi-Ahari
Sahand University of Technology
aminahari95@gmail.com
N
Transient liquid phase (TLP) bonding of AISI 304L stainless steel was carried out using BNi-2 amorphous interlayer. The microstructure of the joint area was studied by using optical and scanning electron microscopes and energy dispersive spectroscopy. The effect of bonding temperature (1030-1110 °C) was studied on the microstructure and corrosion behavior of the TLP bonded samples. Electrochemical corrosion resistance of the bonded samples was evaluated in 3.5% NaCl solution at room temperature. The mechanism of the microstructure formation and the solidification sequence at the joint area were discussed. Ni- and Cr-rich borides, Ni-Si-B compound and fine Ni3Si particles were identified in the γ-Ni matrix at the joint centerline. The microstructural investigations revealed that the solidification sequence of these phases is: L→ γ + L → γ + Ni boride + Cr boride + L → γ + Ni boride + Cr boride + Ni-Si-B Compound. The highest corrosion resistance was observed in the sample bonded at 1070 °C for 30 min, which is comparable to that of the as-received AISI 304L stainless steel. It was attributed to the bond region microstructure with a negligible amount of eutectic constituents formed in the athermally solidified zone.
Transient liquid phase bonding, AISI 304L stainless steel, Isothermal solidification, Microstructure, Corrosion resistance
http://jwsti.iut.ac.ir/article-1-383-en.html
http://jwsti.iut.ac.ir/article-1-383-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Similar Joining of NiTi Shape Memory Alloy using Nd:YAG Pulsed Laser Welding
89
101
FA
Homam
Naffakh-Moosavy
Tarbiat Modares University
h.naffakh-moosavy@modares.ac.ir
Y
0000-0003-0625-4247
Ali
Rasouli
Tarbiat Modares University
alirasouli@modares.ac.ir
N
In this research similar joining of NiTi shape memory alloy was studied. For this purpose, NiTi alloy in the form of wires with circular cross section possessing martensitic phase structure at room temperature was used. By utilizing Nd:YAG pulsed laser welding method followed by optimizing its technical parameters, a defectless joint in terms of appearance and metallurgical properties was obtained. In the next step, the effect of various pulsed laser duration time on properties of the obtained similar joint of NiTi was investigated. Moreover, the resultant microstructures were studied using optical microscope (OP) and Scanning Electron Microscope (SEM) equipped with chemical analysis of EDS. Furthermore, the samples prepared under different pulsed laser duration time conditions were characterized by using tensile and micro-hardness tests. Investigating the results of the performed evaluations revealed that higher levels of heat input has resulted in grain growth, dissolution of precipitations as well as reduction in hardness and ultimate tensile strength of the samples in the joint zone.
Pulsed Nd:YAG laser welding, Shape memory alloy, NiTi, Microstructure
http://jwsti.iut.ac.ir/article-1-386-en.html
http://jwsti.iut.ac.ir/article-1-386-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Laser clading of Inconel 625 on ASTM A575 steel
103
112
FA
M.H.
Zakeri
mhzakeri1365@gmail.com
Y
A.R.
Nasresfahani
NASR-ALIREZA@YAHOO.COM
N
S.M.
Barekat
M-BARKAT@YAHOO.COM
N
In this research, the microstructure of Inconel 625 cladded layer on ASTM A575 steel has been investigated. By examining different parameters, the optimal single-pass sample with the least amount of dilution, porosity and fusion and suitable wetting angle was determined. Then cladding process with the optimal parameter was performed. The microstructure of the cladding layer was evaluated from the base metal to the top. Due to different cooling rates, dendritic morphologies were observed at different distances. Also, the cladding layer was free of any cavities, porosity and cracks and its thickness was 0.9 mm (900 micrometers). The results of (XRD) and (EDS) analyzes indicate thatthe γphase is formed and there is a relatively uniform distribution of elements in the cladding layer. These results also indicate that no change in the chemical composition of the substrate surface was achieved near the interface.The hardness test results also show that the hardness starts from 450 VHN at the top surface and reaches to 135 VHN in the base metal with a gentle slope. This slope of hardness can be attributed to the cooling or heating rates of the substrate.
Laser Cladding, Inconel 625, A575 steel, microstructure, hardness, cladding parameters
http://jwsti.iut.ac.ir/article-1-376-en.html
http://jwsti.iut.ac.ir/article-1-376-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Effect of friction stir welding parameters on the microstructure and mechanical properties of dissimilar AA2024-AA6061 joints
113
125
FA
Seyedeh Zahra
Anvari
szanvari@pnu.ac.ir
Y
0000-0002-9261-3052
Meysam
Khandozi
szaanvari@gmail.com
N
0000-0000-0000-0000
In the present study, to resolve the problems in fusion welding methods as well as to increase the strength, FSW method was used to join aluminum alloy sheets 6061 and 2024. Moreover, optimal parameters for joining of these two alloys were also taken into consideration. Various tool rotation speeds of 565, 950 and 1500 rpm were selected. For each tool rotation speed, two traverse speed variables, two penetration depth variables, and two tool angle variables were specified. The analysis of mechanical properties of welded samples was conducted through tensile and micro-hardness tests. Furthermore, microstructure of welding zone was investigated using optical and electron microscopes. The ratio of shoulder diameter to pin diameter is among the most significant and practical factors for welding tools. So, a shoulder diameter three times larger than that of pin diameter was selected. In the present study, alloy 2024 was placed at the precursor as the harder alloy. Tensile strength and indentation hardness of optimal specimen 300 MPa and 85 HV were achieved. Moreover, hardness behavior and tensile strength of heat-affected zone (HAZ) was evaluated to be lower in alloy 6061 compared to other zones.
Friction stir welding, Aluminum alloys, AA2024, AA6061
http://jwsti.iut.ac.ir/article-1-384-en.html
http://jwsti.iut.ac.ir/article-1-384-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Effect of buffer layer and electrode composition on the mechanical properties of H13 steel repair welds using shielded metal arc welding
127
137
FA
Behrooz
Beidokhti
beidokhti@um.ac.ir
Y
0000-0002-1551-7542
Amin
Ghorbani
amin.ghorbani.91@gmail.com
N
0000-0000-0000-0000
The present study investigated the effect of electrode composition and buffer layer on the microstructure and mechanical properties of H13 tool steel repair welds. Three specimens were welded applying two conditions; i.e. with and without stainless steel underlay. The microstructure of all weld metals contained the martensitic matrix with distributed chromium carbide precipitations. The microstructure of the underlay was a mixture of austenite and layers of ferrite with the skeletal morphology. The results showed that hardness of the welded substrates with underlay was higher than that of the specimens without underlay. This difference could be more than 240 HV. However, the highest hardness values were obtained in the heat affected zone of welds. The application of tough underlay improved the weld toughness and bending properties of the welded specimens. Also, it encouraged the ductile fracture mode in weldments. Also, the higher hardness of weld metal could be resulted from the application of buffer layer.
Hot work tool steel, Welding, Mechanical properties, Underlayer
http://jwsti.iut.ac.ir/article-1-385-en.html
http://jwsti.iut.ac.ir/article-1-385-en.pdf
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
2676-6787
7
2
2022
1
1
Presenting a model for assessing the risk of welding cracks using the ّFBWM method
139
150
FA
M.
Karbasian
mkarbasi@mut-es.ac.ir
Y
0000-0001-9132-5078
N.
Adabavazeh
nazilaadabavazeh@yahoo.com
N
0000-0002-2586-1216
M.
Nikbakht
nikbakht2020@yahoo.com
N
0000-0002-0328-6775
One of the most dangerous industries is welding and inspection. Risk assessment is a rational procedure for determining the probable repercussions of prospective incidents on people, materials, equipment, and the environment. The risk assessment identifies the efficacy of selected control mechanisms and offers essential data for risk reduction, risk management, control system enhancement, and risk response planning. The current study identified 13 dangerous parts of the "hot crack" and "cold crack." The discovered dangers were then ranked by expert academics in the welding and inspection industries using the best worst fuzzy method. A fuzzy method has been developed to address risk uncertainty and minimize decision inconsistencies. The findings indicate that the primary risk factors for weld metal hot cracking in order of importance are "frozen structure, separation, high tensile stresses in the weld metal, material composition, bonding, preheating, high flow intensity, high-thickness workpiece, and weld pollen form." And "the quantity of hydrogen in the weld metal, high tensile stresses, a vulnerable structure, and a relatively low temperature" are all factors in cold welding of weld metal. The study's results may be used to guide the selection of solutions, remove the primary dangers, and establish security policies in the welding and inspection industries.
Risk assessment, Cracking, Welding, FBWM.
http://jwsti.iut.ac.ir/article-1-387-en.html
http://jwsti.iut.ac.ir/article-1-387-en.pdf