Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Effect of welding parameters on penetration depth in FB-TIG welding of 5083 aluminum alloy
1
17
FA
R.
Karimpoor
Department of Materials and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.
A.
Farzadi
Department of Materials and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.
A.
Ebrahimi
Department of Materials and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.
In the present study, effect of current, welding speed and preheat temperature during FB-TIG welding of AA5083 aluminum alloy was studied. Using the Taguchi method, 9 different tests were designed to investigate the effect of welding parameters on the penetration depth. Consistent with predictions, increasing the current and preheat temperature, and reducing the welding speed led to an increase in penetration depth. The maximum penetration depth of 8.02 mm was achieved at the current of 220 A, welding speed of 120 mm/min, and the preheat temperature of 100 °C. Taguchi analysis showed that increasing the welding current and preheat temperature had a more significant effect than the welding speed. Microstructural analysis indicated that the weld metal is fine-grained, along with coarse-grain in the HAZ of all samples. Many pores were observed in the samples with high welding speed and high welding current in the fusion zone. The sample with the highest heat input had the highest penetration depth. This sample had the highest elongation, equal to 69% of the base metal. Moreover, microhardness test demonstrated that the hardness of this sample dropped sharply from 70 Vickers to 58 Vickers in the HAZ.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
The effect of welding parameters on the formation of S-shape defects in friction stir welding of aluminum 1085
19
27
FA
N.
Ebrahimi
F.
Omidbakhsh
In this paper, the effects of welding parameters involving tool shape, title angle, rotational speed and welding speed on the S-shape defect formation have been investigated. For this purpose friction stir welding process were done on the Al-1085 plates by cylindrical, Triangle and square pins. The welded sections were studied by metallographic, radiography and SEM methods. The results showed that the S-shape defect was formed in the 1120 rpm, 1º title angle, 160mm/min welding condition. It is believed that the higher heat input in this welding condition with low welding speed would lead to more oxidation of Aluminum and so oxide particles formation. These oxide particles precipitate in a S shape pattern during the materials transfer between Advancing Side and Retreating Side sites which leads to S-shape defect formation.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Effect of Laser Spot Welding Variables on Microstructure and Mechanical Properties of the Ti-6AL-4V to AISI304 Dissimilar Joint
29
39
FA
M.
Rafi
Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran.
H.
Sabet
Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj, Iran.
V.
Abouei Mehrizi
Advanced Materials Engineering Research Center, Karaj Branch, Islamic Azad University, Karaj, Iran
In this project, joining Ti-6Al-4V and AISI 304 dissimilar plates by laser-spot-welding method has been studied. In this regard, Ti-6Al-4V and AISI 304 plates, with a thickness of 0.7 and 0.5 respectively, were lap-welded using an interlayer of 0.2 & 0.3 mm copper and silver (pure silver). The process was done by 400Watt pulsed laser (Nd:YAG) using oncentric spot welding with 4mm diameter circles as lap welding. Once the spots were created, they got studied and surveyed first by eye inspection, then by optic metallography inspection and finally, by tensile strength and SEM; of course, if cracks were not detected on joining. The results proved copper a better interlayer compared to silver: no joining occurred while using silver as an interlayer for 3 milliseconds, and replacing the upper metal didn’t change the outcome. The best joining result was observed when AISI 304 was placed above (near the laser), copper plate interlayer was used in 7 milliseconds, with 15 Hz frequency, 10.7 J heat input and 1.5 KW peak-power. This way, sheer strength equaled 160 MPa and micro hardness equaled 504 HV.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
The effect of tool transverse speed on the properties of aluminum-steel dissimilar joint by friction stir welding
41
50
FA
M.
Alimadadi
The School of Metallurgy and Materials Engineering of Iran University of Science and Technology
M.
Goodarzi
The School of Metallurgy and Materials Engineering of Iran University of Science and Technology
S.M.A.
Boutorabi
The School of Metallurgy and Materials Engineering of Iran University of Science and Technology
This present study aimed to create an Al6061-St52 dissimilar joint and investigate the effect of the transverse speed by the friction stir welding process. Welding aluminum to steel is rugged by fusion methods because of the formation of brittle intermetallic compounds (IMCs). Therefore, to designate optimal parameters, acceptable IMC thickness, and mechanical properties determined. This research carried out different three transverse speeds of 16, 40 and 85 mm/min (with a constant pin offset of 0.2 mm). Geometry of tool's pin radius and height is 4mm and 1.8mm, respectively. In the transverse speed parameter, the highest ultimate tensile strength (UTS) of 200 MPa was obtained at 85 mm/min. According to the Energy Dispersive X-ray Spectroscopy results, an IMC layer formed in the joint interface. The heat input rate was calculated to designate the optimal parameters. In tensile specimens, fracture mainly occurred in the joints and within the aluminum stir zone due to the combination of thick IMC layer and steel fragments, respectively. The micro-hardness measurement results showed that at (85 mm/min) the hardness values were HV 75 in the aluminum stir zone and HV 315 in the AS vicinity of the interface region. This hardness value is much higher than the base metals (Aluminum base metal is an average of HV 53 and an average steel base metal of HV 245).
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Effect of Speed and Number of Pass in Friction Stir Welding on the Mechanical and corrosion behavior of Commercial Pure Copper
51
60
FA
Mojtaba
Vakili-Azghandi
Department of Materials Engineering, Faculty of Engineering, University of Gonabad, Gonabad, Iran
Ali
Shirazi
Department of Mechanical Engineering, Bu-Ali Sina University, Hamedan, Iran
The results showed that the microhardness and tensile strength of the heat-affected zone as the weakest welding zone in some samples reduced up to 30% compared to the base metal. On the other hand, a decrease in rotational speed, an increase in tool movement speed, and the number of welding passes cause grain refinement and improve mechanical properties. However, the effect of decreasing the rotation speed and increasing the tool movement speed were shown to be more favorable due to less heat production. Accordingly, the hardness in the welded zone with a rotational speed of 600 rpm and a movement of 80 mm/min increased from 90 to 125 HV compared to the base metal, and the hardness reduction in the zones around the welded zone was only 5 Vickers. It was also found that reducing the grain size of the stir zone, while improving the mechanical properties leads to increasing the density of the surface pasive layer, preventing the attack of aggressive chlorine ions and thus reducing the corrosion intensity by 50 times in saline seawater.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Experimental Effects Investigation of Ultrasonic Spot Welding on Dissimilar Al3105 and Al1050 Alloys Joining
61
70
FA
H.R.
Masoumi
Department of Materials Engineering, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan
H.
Razavi
Department of Mechanical Engineering, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan
A.H.
Meysami
Department of Materials Engineering, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan
M.
Khodaei
Department of Materials Engineering, Golpayegan College of Engineering, Isfahan University of Technology, Golpayegan
The aluminum alloys of Al1050 with thickness of one millimeter and Al3105 with thickness of half millimeter were joined via ultrasonic spot welding (USW). To create a suitable welding, a vibrating horn (welding tool) fit to transducer and ultrasonic generator was designed using ANSYS software. Due to mechanical and thermal cycles during USW, both diffusion and mechanical mixing facilitated the formation of welded interfaces. The alloying element, Mn, in Al3105 diffused into Al1050 during USW, and diffusion behavior varied with selection of top sheet. The fracture mechanism during lap shear testing, i.e. debonding or pullout fracture, varied based on welding power, time and pressure of jack. The optimal point for the existing welding conditions was obtained. The best welding conditions were for 750 W at 2 and 3 seconds when the horn was held on the overlap of the sheets. Also, in the tensile test, sheet rupture was performed around the welding spot (out of welding spot).
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Investigation of the effect of heat input on the properties of HSLA 100 steel weld joints produced by SMAW process
71
80
FA
Mehdi
Asle Taghipour
Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Reza
Dehmolaei
Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Seyed Reza
Alavi Zaree
Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Mohammad Reza
Tavakoli shoushtari
Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran
The microstructure and mechanical properties of HSLA-100 steel weld joints was investigated. Welding with three heat input of 0.820, 1.176 and 1.392 kJ / mm was performed using E12018 electrode. Microstructural studies were performed using scanning electron and optical microscopes. The mechanical properties of welded joints were evaluated by impact and microhardness tests. Microstructural studies showed that with increasing the heat input, the amount of acicular ferrite in the weld metal decreased and the amount of polyhedral and quasi-polygonal ferrite increased. It was found that with increasing the heat input, the amount of layered bainite in the heat affected zone increased and the amount of granular bainite decreased. Due to the decrease in the amount of acicular ferrite in the weld metal microstructure with increasing inlet temperature, the amount of hardness and impact energy decreased. The results showed that the increase in heat input due to the reduction of the acicular ferrite of the weld metal and the dissolution of precipitates in the coarse grain heat affected zone has caused a decrease in hardness in these zones. It was found that with increasing the heat input due to decreasing the acicular ferrite, the impact energy of the weld metal decreased by 29% (from 45 joules at an heat input of 0.82 to 32 joules at an heat input of 1.392 kJ / mm). It was found that at all heat inputs, the impact energy of the base metal is greater than the impact energy of the weld metal.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
The effect of bonding temperature on the microstructure and mechanical properties of 939 super alloy by transient liquid phase bonding method
81
88
FA
H.
Tazikeh
Faculty of Materials Engineering , Amirkabir University of Technology
S. E.
Mirsalehi
Faculty of Materials Engineering , Amirkabir University of Technology
A.
Shamsipoor
Faculty of Materials Engineering , Amirkabir University of Technology
In this research, the effect of bonding temperature on the microstructure and mechanical properties of Inconel 939 super alloy by transient liquid phase bonding method. For this purpose, the middle layer of MBF20 with a thickness of 50 microns and three temperatures of 1060 °C, 1120 °C, 1180 °C and a time of 45 minutes have been used. In order to evaluate the microstructure, a scanning electron microscope equipped with an elemental analysis system has been used. Vickers hardness test and shear strength test have been used to evaluate the mechanical properties. The research findings showed that with increasing temperature from 1060 °C to 1120 °C, the width of the athermal solidification zonedecreased from 38µm to 35µm and with increasing temperature at 1180 °C, the athermal solidification zone was completely removed and isothermal solidification zone was replaced. In addition, with increasing temperature, the hardness in the joint center decreases and the shear strength increases.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Evaluation of microstructural properties and investigation of corrosion behavior of P460NH welded steel using E8018-G electrode
89
96
FA
Hossein
Tahmasebi Manesh
Department of Materials Engineering, Malek Ashtar University of Technology, Isfahan.
Alireza
Nasresfahani
Department of Materials Engineering, Malek Ashtar University of Technology, Isfahan.
Alireza
Nasresfahani
Department of Materials Engineering, Malek Ashtar University of Technology, Isfahan.
One of the applications of P460NH micro-alloy steel is its use in pressure vessel tanks. Electrode E8018-G can be used for welding this steel. In this study, to obtain the optimal welding parameters, the arc process based on ASME IX standard was used. Then, by sampling from the weld section, Vickers hardness test was performed and hardness profiles were drawn in different areas. Then the microstructure of each area was examined and compared with the hardness test results. The corrosion behavior of the heat affected zone, weld zone and base metal was investigated separately using the TOEFL polarization test in a 3.5% solution of NaCl. The results showed that the weld zone had the highest percentage of perlite (62%) and the base metal had the highest percentage of ferrite (73%). Also, the heat affected zone has the highest hardness number (298) and the base metal has the lowest value (210) in the Vickers scale. Evaluation of corrosion behavior of different areas also showed that the heat affected zone has the highest corrosion potential (-.651v) and the lowest corrosion current density (1.75×10-5 A/cm2). This is while the base metal has the lowest corrosion potential (-.691v) and the highest corrosion current density (1.2×10-6 A/cm2) compared to the weld metal and the heat affected zone.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Investigation of the ultrasonic welding strength in glass fiber reinforced thermoset polymers with surface preparation method using laser beam
97
106
FA
hamed
tirband
Tarbiat Modares
davood
Akbari
Tarbiat Modares
mohammad
golzar
Tarbiat Modares
In this research, tensile strength of ultrasonic welded parts made of thermoset polymer-reinforced glass fiber with surface preparation has been investiagted. In order to elevate the adhesion of two surfaces laser grooving method has been applied. Two type of thermoplastic materials including Plymethyl methacrylate (PMMA) and polypropylene (PP) have been used as interlayers. Influences of main welding parameters were investigated. The results show that the force and compression parameters in these joints have been ineffective parameters and in higher weld welds, the thermosetting resin has started thermal degradation. The pressure considered constant and set at 2 bar, welding time set at 1.6 seconds and holding time considered 3 seconds. The results showed that the minimum tensile strength of welded samples with laser surface preparation method is 1286 N, which is much more than maximum tensile strength of welded samples without any surface preapration. This indicates that laser beam surface preparation is an effective method in improving of the adhesion strength of thermoset polymeric parts.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Prediction of Weld Strength in Resistance Spot Welded Samples by Adaptive Neuro-Fuzzy Inference System (ANFIS)
107
117
FA
Mehdi
Safari
Arak University of Technology
Amir Hossein
Rabiee
Arak University of Technology
Jalal
Joudaki
Arak University of Technology
Resistance Spot Welding (RSW) is one of the effective manufacturing processes used widely for joining sheet metals. Prediction of weld strength of welded samples has great importance in manufacturing and different methods are used by researchers to find the fracture force. In this article, the Adaptive Neuro-Fuzzy Inference System (ANFIS) is utilized for prediction of joint strength in welded samples by RSW. A design of experiments (DOE) is prepared according to effective process parameters includes welding current, welding cycle, cooling cycle and electrode force. The sheet metal samples prepared from AISI 1075 carbon steel. Tensile test specimens are prepared and the tensile-shear strength of welded samples are measured. A model is developed according to ANFIS and trained according to teaching-learning based optimization algorithm. 70 % of test data used for network train and the remained 30 % used for access the accuracy of trained network. The accuracy of the trained network was assessed and the results show that the trained network can predict the joint strength with high accuracy. The determination factor (R2) and mean absolute percentage error (MAPE) are 0.99 and 0.48 % for trained data and 0.95 and 6.2% for test data.
Iranian Institute of Welding and Non Destructive Testing
Journal of Welding Science and Technology of Iran
2476-583X
7
1
2021
8
1
Optimization of friction stir welding parameters for toughness in super duplex stainless steel
119
127
FA
Mohammad
Yousefieh
Semnan University
In this paper, using the Taguchi method, the parameters affecting the toughness of super duplex stainless steels in friction stir welding were optimized. In order to achieve optimal conditions, maximum toughness, the quality characteristic was used as the higher the better. Analysis of Taguchi results showed that in order to achieve optimal conditions in super duplex stainless steel weldments must have a tool rotational speed of 500 rpm, a welding speed of 60 mm / min, an initial pressure of 70 MPa and a tool tilt angle with the workpiece is equal to 3 degrees. Under optimal conditions, the toughness obtained from the confirmation test was 61 J, which was very close to the predicted toughness (58 J). Analysis of variance was also performed on the results of signal to noise (S/N) ratio. According to the results of analysis of variance, the tool rotational speed parameter with an influence percentage of 64% was the most effective parameter on toughness in friction stir welding of super duplex stainless steels. On the other hand, the parameters of welding speed (with an influence percentage of 17 %), initial 2 pressure (with an influence percentage of 16%) and tool tilt angle to the workpiece (with an influence percentage of 3%) were in the next ranks. Also, SEM micrographs from fracture surface of the samples in the impact test proved that the sample that had the least toughness in the impact test had a cleavage morphology and as a result, brittle fracture. This was while the morphology of the fracture surface of the tested sample under optimal conditions (with the highest toughness in this study = 61 J) had a large amount of fine and deep dimples. The presence of these dimples in large quantities indicated ductile fracture and eventually reaching the highest toughness.