per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 1 8 article M. Hajizadeh 1 S. Emami Saeid@sut.ac.ir 2 T. Saeid 3 Friction stir welding was conducted on AISI 304 austenitic stainless steel sheet with dimensions of 100 mm × 100 mm × 2 mm. The FSW was performed at a welding speed of 150 mm/min and rotational speeds of 400 and 800 rpm. The results showed that high frequency of low angle grain boundaries (LAGBs) were formed through dynamic recovery in the thermo-mechanically affected zone (TMAZ). Higher amount of LAGBs were developed in the TMAZ of welded sample with 800 rpm due to the higher amount of strain and heat generated. High fraction of high angle grain boundaries were formed in the stir zone (SZ) of the welded samples through the occurrence of continuous dynamic recrystallization (CDRX). A very fine microstructure developed in the sampled welded with lower rotational speed. Analysis of texture using {111} Pole figures showed the formation of shear texture components in the SZ of both welded samples. The intensity of the obtained texture for the sample welded with 800 rpm was greater. The formation of shear texture components in the SZ of both samples implied the occurrence of CDRX mechanism http://jwsti.iut.ac.ir/article-1-290-en.pdf Friction stir welding Stainless steels Dynamic recovery Dynamic recrystallization Shear texture per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 9 17 article Ramin Delir Nazarlou ram.delir69@gmail.com 1 Faraz Omidbakhsh f.omidbakhsh@gmail.com 2 Javad Mollaei Milani J_mollaei@sut.ac.ir 3 Friction stir welding (FSW) is an economic and high quality technique at aluminum welding and joining methods. The most important factor in the soundness of this type of welding, is the mechanism of material transfer in each tool rotation. The materials transfer during the welding process involves horizontal and vertical movement that caused by extrusion process and forging force (the tilt angle due to forging force and on the other hand, shape of pin due to the extrusion process). One of the most important parameters in FSW process is the effect of rotational speed in the welded zone. In this study, the effect of rotational speed at constant welding speed, in the butt joint of pure commercial aluminum, was investigated. The results of the study showed that, increasing the rotational speed due to increases the amount of material transfer in the weld zone. The welded zone was investigated by appearance weld zone experiments and using radiography tests. Also weld zone was investigated in macro and microstructure by using cross section. Then the micro hardness testing has been used by cross section at welded zone. In order to investigate the mechanism of materials transfer during the process, the electrical resistivity test has been used to analyses the amount of materials transfer in the weld zone. Results shows that, increasing rotational speed due to increasing the amount of materials transfer in the weld zone and decreasing the amount of defects in the weld zone.   http://jwsti.iut.ac.ir/article-1-245-en.pdf Friction stir welding Material flow path radiography Rotational Speed Pure commercial Aluminum per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 19 32 article S. A. A. Hashemi Milani 1 R. Tavangar 2 M. Azadbeh 3 Kahinpoor 4 H. Sadeghi-Nasab 5 Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. Iran Radiator Co., Tehran, Iran. Iran Radiator Co., Tehran, Iran. During the brazing of aluminum-based heat exchangers, the flux dry-off temperature plays a crucial role to get sound joints with maximum strength. In the present study, the NOCOLOK® flux consists of two phases of K2AlF5.H2O and KAlF4 with a melting point around 580 °C was used for brazing AA3003 as base metal with a clad-coating of AA4343 as filler metal. The slurry was applied on the joints and they dried at 220, 300 and 380 °C in air. The tensile shear test revealed that when the slurry dried at 300 °C, the joint withstand maximum shear stress of 44 MPa without defective features. At 220 °C and 380 °C, joint shear stresses were 34 MPa, 30 MPa respectively. However, drying at 380 °C under protective nitrogen gas enhanced the shear strength of up to 39 MPa. Having applied a change in current dryer temperature in the factory from 360 °C to 300 °C reduced the percentage of heat exchangers leakage from 3.2% to 0.6%, approximately, on a weekly basis. http://jwsti.iut.ac.ir/article-1-293-en.pdf Brazing of aluminum NOCOLOK® flux Aluminum-silicon. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 33 48 article F. Pahnaneh 1 M. Aghakhani * 2 R. Eslami Farsani 3 M. Karamipour1 4 This paper reports the applicability of fuzzy logig (FL) to predict the hardness of melt zone (HMZ) during the gas metal arc welding (GMAW) process, which is affected by the combined effect of ZrO2 nano-particles and welding input parameters. The arc voltage, welding current, welding speed, stick-out, and ZrO2 nano-particles were used as the input parameters and HMZ as the response to develop FL model. The predicted results from FL were compared with the experimental data. The most important input parameter affecting the HMZs was the addition of ZrO2 nanoparticle coatings with a thickness of 1 mm, which increased the hardness from 78 to 84 HRB. The correlation factor value obtained was 99.98% between the measured and predicted values of HMZ. The results showed that FL is an accurate and reliable technique for predicting HMZ because of its low error rate. Also, the presence of ZrO2 nano-particles in the weld pool has increased the penetration up to 2 times.   http://jwsti.iut.ac.ir/article-1-299-en.pdf Gas metal arc welding Hardness of melted zone ZrO2 nano-particles Fuzzy logic Weld penetration. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 49 55 article S. Emami 1 T. Saeid 2 Single phase brass strips with 2 mm thickness were severely deformed through 1 and 3 cycles of accumulative roll bonding process (ARB). ARB process effectively increased the hardness, yield strength, and the ultimate strength of the processed materials. The hardness of processed material increased from 95 HV in annealed material to 225 HV in 3 cycle ARBed material, and the yielding and ultimate strengths increased more than 5 and 2 times of the annealed sample, respectively. Friction stir welding (FSW) process was successfully conducted on the annealed and ARBed samples to investigate and compare the microstructure and the mechanical properties of the joints obtained in bead on plate configuration. Microstructural observations showed that very fine dynamically recrystallized grains developed in the stir zones (SZs) of all welded samples. Mechanical properties were evaluated by hardness and tensile testing. Hardness test for the ARBed and FS welded samples showed that the hardness value decreased by 110 Hv in the resultant SZs. Results of tensile testing revealed that yield and ultimate strength of the FS welded ARBed samples 1.3 and 1.8 times are greater than that of the annealed FS welded sample . http://jwsti.iut.ac.ir/article-1-300-en.pdf Severe plastic deformation Friction stir welding Single phase brass Dynamic recrystallization. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 57 65 article A. Ghandi 1 M. Shamanian 2 M. R. Salmani3 3 The structural and hardness developed in advanced high-strength steel DP590 have been investigated with the help of optical microscopy and scanning electron microscopy on resistance spot welded specimens. The hardness diagram of the weld sections was prepared by microhardness test and the temperature peak and heat distribution were simulated by menas of the Abaqus software. The results show that according to the temperature generated in each region of the weld nugget, the HAZ and base metals have different microstructures, and these difference affects the hardness of the regions. The presence of tempered martensite islands with a fraction of 44% in ferrite matrix in base metal, mainly martensitic structure in the nugget, and martensitic structure along with scattered areas of ferrite in the HAZ was observed. The results of the microhardness tests showed difference in hardness values of the regions, and also it was observed that the hardness values increased in the HAZ and weld zone. The hardness values measured in the nugget, base metal, and HAZ were around 400, 200, and 450 HV which were in accordance with the observed structures http://jwsti.iut.ac.ir/article-1-301-en.pdf Advanced high strength steel DP590 Spot resistance welding Microstructure Microhardness Simulation per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 67 80 article H. R. Alinaghian 1 S. A. Sadough Vanini 2 S. M. Monir Vaghefi 3 Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran The surface of continuous casting moulds with high number of castings may be worn or destructed. As result, an approach for increasing these moulds life is necessary. In this project, the goal is the restoration of the DHP copper sample. In this project, the destruction of the copper sample is done by creation of groove using a CNC machine. The restoration of the sample is done using OAW and filler to fill groove area. In this project, the effect of preheating temperature, filler type and heat treatment of welding area on hardness, microstructure, chemical analyses of welding area and thermal conductivity of the weld are investigated. The preheating temperature range of 300 to 450oC was selected. The Cu-P and Cu-Ag-P fillers were chosen to fill the groove of the weld area. The scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDS), micro hardness tester, optical microscope and thermal conductivity meter were employed for evaluation of the results in this project. The results showed that the increase of preheating temperature creates oxide layers and the decrease of preheating temperature causes the incomplete filling of the welding area. Finally, the preheating temperature of 400 oC was a proper choice considering the above mentioned factors. The stress relieving operation to decrease stress and preserve the mechanical properties in the temperature of 250 to 400 oC and duration two hours was carried out. The result demonstrated that the selected temperature causes no unwanted decrease on the hardness. It was also found that increasing the annealing duration, decreases the hardness of weld for Cu-P filler for Cu-Ag-P filler increasing the annealing duration, first decreases the weld hardness and then increases the weld hardness. The Cu-P filler was compared with Cu-Ag-P filler. The results showed that the Cu-Ag-P filler has less hardness (around 10 percent) than the filler without silver. On the other hand, the thermal conductivity of the Cu-Ag-P filler was around 10 percent more than the thermal conductivity of the Cu-P. It is obvious that the selection of the filler type depends on the type of base metal and its geometry. The results showed that the segregation in the Cu-P filler with 7.2 percent phosphorous, because of the proximity of the weld structure to the eutectic point, has slightly happened; while, the selection of the Cu-Ag-P filler with 6 percent silver caused severe segregation of silver to 90 percent silver at the center of weld at the non-dendrite area http://jwsti.iut.ac.ir/article-1-302-en.pdf DHP copper Repair of failing Welding filler Micro-hardness Microstructure Annealing per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 81 95 article 1 2 3 Advanced Materials Engineering Research Center, Karaj Branch, Islamic Azad University, Karaj, Iran Advanced Materials Engineering Research Center, Karaj Branch, Islamic Azad University, Karaj, Iran Advanced Materials Engineering Research Center, Karaj Branch, Islamic Azad University, Karaj, Iran In this research, effect of time and temperature of TLP process on the microstructure, mechanical properties and corrosion resistance of CP-Ti to 316L stainless steel joint evaluated. For this purpose pure copper foil with 100 µm thickness was used as interlayer and joining process carried out at 950˚C, 1000˚C and 1050˚C and for 90, 120 and 150 minutes. After the joining process, shear and micro-hardness test and corrosion resistance were applied in the samples. The test results revealed that the shear strength of the sample 1000˚C is better than two other soaking temperatures. The main reason was the formation of less intermetallic compounds at the interface, as well as the presence of less athermally solidification zone area. Microstructural examinations for the sample after TLP at 950˚C revealed no iron and titanium bearing intermetallic compounds in the interface while for two other samples, there exist considerable amount of intermetallics in the microstructure. Corrosion test results showed that the resistance against corrosion depends on the intermetallic compounds formed in the interface. Intermetallic phases includes FeTi, TiCu, Ti2Cu, and TiCu2. The sample prepared at 1000˚C for 120 minutes had less intermetallic compounds and as a result, had the best corrosion resistance. Fe and Ti containing intermetallics had good corrosion resistance in simulated body fluid, as comparison with Ti and Cu containing compounds. http://jwsti.iut.ac.ir/article-1-305-en.pdf Transitional liquid phase bonding process Dissimilar metal bonding 316 L steel Commercial pure titanium. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 97 113 article M. Rostami 1 H. Khorsand 2 Faculty of Materials Science and Technology, K. N. Toosi University of Technology, Tehran, Iran. Faculty of Materials Science and Technology, K. N. Toosi University of Technology, Tehran, Iran. The conventional eddy current method for non-destructive inspection of welding joints has limitations that can examine defects to a certain depth below the surface of the sample and is not suitable for determining deep defects. This limitation can be overcome using the SQUID superconducting sensors. The nonstoichiometric composition of YBCO due to its superconducting temperature and desired critical current density is widely used including the use of highly sensitive SQUID sensors. The properties and temperature of the superconducting compound are related to producing pure and homogeneous with a precise ratio of this non-stoichiometric compound in phase Y:123. In this study, the production of this high-temperature superconductor was carried out using a sol gel self-combustion process with nitrate forming elements and then produced powder analyzed by TGA, XRD, scanning electron microscopy, and EDX method and optimum conditions for production of Y:123 superconducting nanopowder were obtained by sol gel self-combustion method. In these conditions, the superconducting phase Y:123 was produced and the impurities were removed and on the other hand, the need for further thermal treatment and the costly annealing process were removed. Finally, optimal conditions for deposition of this compound on the substrate for producing the SQUID sensor were investigated and an optimal condition was presented to produce thin layer YBCO deposited by pulsed laser deposition method and patterned to produce SQUID High temperature Superconductor SQUID sensor. Finally the SQUID based NDT test for detecting sub-surfaces defects was investigated. http://jwsti.iut.ac.ir/article-1-306-en.pdf High temperature superconductor SQUID YBCO SrTiO3 substrate Sol-gel self-combustion Non-destructive test. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 115 132 article M. Bekrani 1 Faculty of Electrical and Computer Engineering, Qom University of Technology, Qom, Iran One of the novel ultrasonic phased array based scanning methods for ultrasonic imaging in non-destructive test is total focusing method (TFM). This method employs maximum available information of the phased array elements and leads to an improved defect detection accuracy compared to conventional scanning methods. Despite its high detection accuracy, TFM behaves weak in distinguishing the real defects from noise which is because of its high background noise level. In this paper, a low complexity technique is presented for performance improvement of TFM which employs a beamforming method on the phased array received signals and leads to a reduction of the background noise and increase in the accuracy of the defect detection. To this end, a thresholding technique along with three-level clipping of the array received data is applied for low-complexity approximation of the correlation matrix inverse employed in the beamforming. Experimental results for detection of drilled holes on a steel pipe show a background noise reduction of 4.45 dB and improvement in the hole distinction of about 3 dB in comparison to those of TFM. In addition, as shown in the simulation results, the minimum distinguishable distance between two neighbor reflector points for the proposed method is 0.21 mm which is 0.23 mm lower than that for TFM. http://jwsti.iut.ac.ir/article-1-307-en.pdf Ultrasonic phased array Non-destructive testing Welding inspection Total focusing method Beamforming. per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 133 146 article M.R. Samadi 1 H. Mostaan 2 M. Rafiei 3 M. Salehi 4 Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Nowadays, aluminum and its alloys have extensive applications in marine and aerospace industrious owing to their excellent properties. Among these alloys, 5xxx series of aluminum alloys have also excellent corrosion resistance, high toughness and strength and also good weldability. Decrease in yield strength and also tensile strength due to the grain growth in the heat affected zone is of the main problems in the welding of these series of Al alloys. In this research work, gas tungsten arc weld joints in two modes i. e. direct current and pulsed current were compared in order to study the effect of this parameter on the microstructure, mechanical properties and corrosion resistance of weld joints. Also, the effect pulsed current parameters such as peak current and basic current were investigated. Microstructural evolutions and fracture surfaces of weld joints were examined by optical microscope and scanning electron microscope, respectively. It was found that the fracture behavior of all joints is in a ductile manner. Also, tensile test and electrochemical polarization were conducted in order to study the mechanical properties and corrosion behavior of weld joints. http://jwsti.iut.ac.ir/article-1-308-en.pdf 5xxx series Al alloys Filler metal Gas tungsten arc welding Corrosion Microstructure per Iranian Institute of Welding and Non Destructive Testing Journal of Welding Science and Technology of Iran 2476-583X 2676-6787 2020-08 6 1 147 156 article P. Shayanfar 1 H. Daneshmanesh 2 K. Janghorban 3 Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran In this study, the effect of overlapping percentage on microstructure and mechanical properties of a single-pass coating by Inconel 625 powder laser has been investigated for quench-tempered ASTM A592 steel. In order to have a structural analysis, the inter dendritic distance was evaluated. For this purpose, scanning electron microscopy (FESEM) and Digimizer software were adopted. In order to investigate mechanical properties, elastic modulus, toughness, and micro hardness were evaluated. For the evaluation of elastic modulus, Noop indentation method was used, and for toughness studies, Evans method was applied. After the investigation, it was found that in the overlapping of single-pass 50% coatings, the heat input value is lower than overlapping in single-pass 75% coatings. It also contains a finer structure with much higher mechanical properties. This is in such a way that the inter dendritic distance in single-pass 50% coatings is about 0.91 µm. The average diameter of the dendritic columns is about 0.32 µm, hardness value is about 10%, Knoop hardness is about 9 units, elastic modulus is about 37 GPa, and toughness is about 9 MPa m1/2 higher in comparison with the 75% overlapping case. http://jwsti.iut.ac.ir/article-1-309-en.pdf Laser cladding Inconel 625 A592 steel Microstructure Mechanical properties