@article{ author = {Razavi, A.S. and Sabet, H.}, title = {The Effect of the AA7075 Interlayer on the Microstructure and Mechanical Properties of the AA1050 Butt Joint Welded by FSW}, abstract ={In this research, the FSW Butt joint of commercial aluminum 1050 was investigated by using the 7075 aluminum alloy interlayer on the linear velocity of 30, 50 and 100 mm / min, and rotational speeds of 800 and 1200 rpm. A threaded cylindrical tool was used for joining of the 5 mm sheets. The OM, SEM, microhardness and tensile tests were done. The results shows that in sample with an interlayer at the condition of the 800 rpm and 30 mm/min the maximum tensile strength and hardness appeared and in the non-layered sample at the 800 rpm and 50 mm/min, the maximum tensile strength and hardness was obtained. The results shows that by using the interlayer the tensile strength and hardness were increase.}, Keywords = {FSW, Al 1050, Al 7075, Interlayer}, volume = {4}, Number = {1}, pages = {1-18}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-214-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-214-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Abbasi, Morteza and Najafi, Hamidreza and Khodabandeh, Alirez}, title = {Welding of 304L Stainless Steel to 409 Stainless Steel with GMAW Process Using ER316LSi and ER309LMo Filler Metals}, abstract ={Dissimilar welding of AISI 304L austenitic stainless steel to AISI 409 ferritic stainless steel with GMAW process usingtwo Ar-O2 and Ar-CO2 shielding gas mixtures was studied. ER316LSi and ER309LMo filler metals were chosen by considering 5 and 15% delta ferrite according to the Schaeffler equations and diagram. Based on the observations, both filler metals accompanied by Ar-2%O2 shielding gas resulted in acceptable weldments. Yield strength and UTS of tensile samples were 288 and 424 MPa, respectively. All tensile samples fractured in the ferritic base metal. Microhardness test results demonstrated that the maximum hardness of 190-200 HV was obtained from ER316LSi weld metal. The minimum hardness of 145 HV was found in the HAZ of 409 side mainly due to the grain coarsening. Microstructural examinations revealed needle-like precipitates formed perpendicular to each other in the HAZ of 409 stainless steel. It seemed that the pre-existing TiC precipitates evolved into the needle shape precipitates as a result of rapid heating and cooling rates during the welding process.  }, Keywords = {GMAW, 304L Stainless Steel, 409 Stainless Steel, ER316LSi, ER309LMo, Shielding Gas}, volume = {4}, Number = {1}, pages = {19-28}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-108-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-108-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {TalebiHanzaei, A. and Marashi, P. and Ranjbarnodeh, E. and Hamdollahzadeh, A.}, title = {The Effect of Hydrogen Content and Welding Conditions on the Hydrogen Induced Cracking of the API X70 Steel Weld}, abstract ={In this study, first,diffusible hydrogen of cellulosic electrode E8010-P1 and low hydrogen electrode E8018-G was measured by mercury displacement method according to ISO3690. Then,the effect of preheating and post-heating on the sensitivity to hydrogen inducedcold cracking in welding of 18mm API5L X70 steel with these electrodes was investigated according to ISO17642-2. The results of visual inspection, penetrant test,metallographic examination, and hardness test showed that welding with cellulosic electrode leads to cracking unless both preheating and post-heating are applied.While in the case of low hydrogen electrode, cracking occurs only if no preheating or post-heating is applied.  }, Keywords = {Hydrogen Inducedcold Cracking, Preheating, Post-heating, Diffusible Hydrogen, API X70 Steel.}, volume = {4}, Number = {1}, pages = {29-41}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-213-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-213-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Tavoosi, Majid and Arjmand, Sajad and Solgi, Saie}, title = {The Influence of Heat-Input on Structural and Mechanical Properties of 2205 Duplex Stainless Steel}, abstract ={The influence of heat-input and pre-heat treatment on the structure, mechanical and corrosion behaviors of 2205 duplex stainless steel joint by means of GMAW process was the goal of this study. In this regards, the welding process was done using different heat input in the range of 0.6 to 1.4 kJ/mm and different pre-heating treatments in the range of 25 to 100 oC. The microstructural properties of prepared samples were evaluated using x-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Based on archived results, the microstructure of as-welded samples were combinations of Widmaneshtaten austenite which nucleated from boundaries and growth toward central part of ferrite grains. By increasing the heat-input, the percentages of ferrite and austenite phases decreased and increased, respectively. In this condition, the highest value of strength and ductility was achieved in as-weld samples with medium (1.0 kJ/mm) heat-input. The corrosion studies showed that the heat-input has negligible effects on corrosion behaviors of 2205 duplex stainless steel joint. It was also found that the pre-heating treatment has adverse effect on the mechanical properties of the junction.    }, Keywords = {Duplex stainless steel, Heat-input, GTAW, Mechanical properties.}, volume = {4}, Number = {1}, pages = {43-54}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-122-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-122-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Siddiqui, M. and Razavi, S. H. and Sabet, H.}, title = {Investigation on the Effect of Post Weld Heat Treatment Temperature on Stress Corrosion Resistance of Inconel 625 Cladded on AISI 4130 Steel Using Hot Wire GTAW}, abstract ={In this research  the effect of heat treatment offer welding (PWHT) in 650,750 and 8500C for two hours on Sulfide stress corrosion cracking resistance (SSC), welding metal Inconel 625 to low alloy steel 4130 was analyzed that was welded using Automatic TIG welding process then the mechanical properties of the joint was observed using micro hardness measure experiment (weld metal, base metal and the welding heat-affected zone) and welding metal structure using light microscopy, electron SEM(EDX), also XRD. The comparison of the microstructure in different temperatures show the least effect on microstructure in 6500C. In micro hardness measure test after post-weld heat treatment (PWHT) with increasing temperature we observed decreasing hardness of base metal and heat-effected zon and alsoincreasing weld metal micro hardness. when the temperature of post-weld heat treatment reached to 8500C phase γ" changed quickly to delta phase δ.when temperature reached to 8500C secondary phases changed to needle form. After stress testing in Sulfide environment magnetic particles (MT) was done on the samples and results showed that in the post-weld heat treatment sample 8500C tension crack is made. Pictures of stress testing(SSC) SEM sample shows that tension cracks mode is base metal cracks along the grain boundaries and it also extends the base metal to weld metal.}, Keywords = {HAZ, Tungsten Arc Welding, Sulfide Stress, Tension Crack.}, volume = {4}, Number = {1}, pages = {55-66}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-211-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-211-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Mahab, A. and Farzam, M. and Dehmolaei, R.}, title = {Effect of Heat Input of Submerged Arc Welding Process on the Corrosion Behavior of API X42 Gas Pipeline Steel Weld Joint}, abstract ={The effect of heat input of submerged arc welding process on the corrosion bahavior of weld metal of API X42 gas pipeline steel weld joint was investigated. For this purpose, 6 annealed sheets of 15mm thickness were prepared from the X42 microalloyed steel. Submerged arc welding process with varying heat input of 37.8, 18.9 and 12.6 kJ/mm was used for joint welding. Then potentiodynamic polarization and electrochemical impedance spectroscopy methods were used to evaluate the corrosion behavior of the welded joints (in 3.5% NaCl solution). The evaluation of the microstructures of the welded metals in the weld joints were conducted using the scanning electron microscopy. X-ray diffraction was used for the analysis of the phases formed in the weld metal microstructure. Scanning electron microscopy observations and patterns obtained from the X-ray diffraction showed that the increase in heat input resulted in the increase in the amount of ferrite. The grain size also increased. Corrosion test results showed that by increasing the heat input of the weld process, the corrosion resistance increased..}, Keywords = {X42 Gas Pipeline Steel, Weld Metal, Corrosion Behavior, Heat Input, Submerged Arc Welding Process}, volume = {4}, Number = {1}, pages = {67-76}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-187-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-187-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {RezaeiAshtiani, H. and Shafiee, M.}, title = {The Mechanical Properties Evaluation of the Welded Sheets of AA 3105 Aluminum Alloy Using Friction Stir Spot Welding (FSSW)}, abstract ={Friction stir spot welding (FSSW) is a type of solid state welding that is used in the connection of small pieces and light metals such as aluminum alloy especially. The technical problem during melting of aluminum alloys is one of the most important reasons for developing application of friction stir welding for aluminum alloys. In this research, the effects of important processing parameters such as tool rotation speed, dwell time, plunge depth of tool and sheets thickness on the mechanical properties such as failure force and energy of FSS welded AA-3105 alloy have been experimentally studied using micro hardness and tensile tests. Tensile-shear tests show four different fracture modes of weld failure which consist of shear fracture, circumferential fracture, nugget pull out fracture and fracture in base material modes. The results show that the weld strength drops with increasing the tool rotation speed. Strength and hardness of weld and weld zone increase and then decrease with increasing dwell time of rotational tool which it can be obtained an optimum value of dwell time. Strength and fracture energy and load of welds increases with increasing the sheet thickness}, Keywords = {Friction Stir Spot Welding, AA-3105 Aluminum Alloy, Weld Strength, Mechanical Properties.}, volume = {4}, Number = {1}, pages = {77-87}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-186-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-186-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {MehrabiSharifabad, H. and Hajisafari, M.}, title = {Effect of Weld Metal Microstructure on the Fatigue and Corrosion-Fatigue Properties of GTA-Welded 304 Stainless Steel}, abstract ={In this research, two different filler metals, ERNiCrMo-3 and ER309L, were used for developing different microstructure, austenite (γ) and austenite and ferrite (γ+δ) in the weld metal and fatigue properties of welded samples were evaluated in the air and sea water environments. Microstructural studies indicated a good agreement between predicted microstructures via schiffler diagram and metallographic studies. Evaluation of fatigue properties in the air and sea water environments revealed the austenitic weld metal, like base metal microstructure, improved the fatigue strength of welded samples. Fractographic studies and FESEM-EDS analysis showed more ductile fracture of welded samples by using ERNiCrMo-3, formation of more uniform and deeper dimples in the final zone of fatigue fracture, than that of welded samples by using ER309L. Furthermore, unlike dimple formation centers in welded samples by using ER309L, Mo-Ti rich intermetallics caused formation of dimples in the welded sampled via ERNiCrMo-3.}, Keywords = {304, Fatigue, Corrosion-Fatigue, GTAW, Chemical Composition, Microstructure.}, volume = {4}, Number = {1}, pages = {89-99}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-185-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-185-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Mostaan, H. and Safari, M. and Sonboli, A. and Haddadi, M. and Taherkhani, A.}, title = {Study and Investigation on the Effect of Presence of Interlayer on the Microstructure, Mechanical Properties and Fracture Mode of AISI 321 Stainless Steel Resistance Spot Welds}, abstract ={In this paper, numerical and empirical investigations of the effect of AISI 347 stainless steel interlayer on the microstructure, mechanical properties and fracture mode of AISI 321 stainless steel resistance spot welds have been conducted. For this purpose, two types of joints, the first free from inter layer and the second contains interlayer with 0.05 mm thickness as well as difference currents and times,were evaluated. In order to examine the mechanical properties including maximum force and tensile mode, tensile – shear test of the spot welds was done. The obtained results indicated that an increase in the welding time and current resulted in a change in fracture mode from interfacial to peripheral owing to an increase in fusion zone volume. The change in the chemical composition because of the presence of interlayer and an increase in cooling rate caused the formation of different phases as well as observation of the dispersed Martensite phase in fusion zone.  }, Keywords = {Resistance Spot Welding, AISI 321 Stainless Steel, Phase Transformations, Mechanical Properties, Fracture Mode}, volume = {4}, Number = {1}, pages = {101-112}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-212-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-212-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {AhlSarmadi, M. and Atapour, M. and Behjat, A. and Edriss, H. and Vahman, M.}, title = {Investigation of Corrosion Behavior and Galvanic Corrosion Simulation of Super Duplex Stainless Steel UNS S32750 Weld Zone}, abstract ={Galvanic corrosion is an ever-present problem in all different environments, particularly in tanks. The goal of this project is to develop a finite element model that can be used with experimental data to characterize the corrosion of a galvanic weldments couple in an electrolyte. In this study sample are welded by gas tungsten arc welding and friction stir welding. According to ASTM G8, Evaluation of corrosion properties examined with cyclic polarization test in 0.5 molar H2SO4 andthe information required to validate the model was prepared. The finite element model is developed using COMSOL and Math Module through derivation of equations describing corrosion thermodynamics and electrochemical kinetics. The results showed that reducing in heat input to improve galvanic corrosion behavior in the weld sample.In addition to result of simulation reveal sample that welded by gas tungsten arc method had higher current density galvanic corrosion in comparison with friction stir sample.}, Keywords = {Super Duplex Stainless Steel, Galvanic Corrosion Simulation, Friction Stir Welding, Gas Tungsten Arc Weldingcture Mode.}, volume = {4}, Number = {1}, pages = {113-126}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-183-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-183-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2018} } @article{ author = {Gholami, M. and Mostaan, H. and Sonboli, A.}, title = {Development of dissimilar GTA 4130/201 SS weld joint and investigation on the effect of filler metals in order to obtain improved mechanical properties and microstructural features}, abstract ={In this research, gas tungsten arc welding of dissimilar joint between 4130 low alloy steel and AISI 201 austenitic stainless steel was investigated. Four filler metals i. e. ERNiCr-3, ER 309L, ER 308L and ER 80SB2 were used. After welding, microstructural features of various areas and also fracture surfaces were examined using optical microscopy and scanning electron microscopy. Tensile test was conducted in order to study the mechanical properties of each joint. It was found that ERNiCr-3 is fractured from fusion zone and the others were fractured from 4130 base metal. Also, some second phase particles such as NbC were seen in the ERNiCr-3 weld joint. SEM observation showed that the fracture behavior of ERNiCr-3 weld joint is semi brittle and the others are ductile. The fusion zone of ERNiCr-3 weld joint was fully austenitic and consisted of equiaxed grains and no crack was seen in this area. The fusion zone of ER 308L and ER 309L were composed from cellular dendrite and finally ER 80S-B2 weld joint was consisted of lath martensite.}, Keywords = {Dissimilar joints, Gas tungsten arc welding, AISI 201 austenitic stainless steel, AISI 4130 low alloy steel, Mechanical properties, Microstructure}, volume = {4}, Number = {2}, pages = {1-12}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-221-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-221-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Vanaee, M. and Ardestani, M. and Abbasi, A.}, title = {Gas tungsten arc welding of direct quenched wear resistant steel to plain carbon steel and evaluation of its microstructure and wear properties}, abstract ={In this research, the dissimilar welding of St52 plain carbon steel to W400 wear resistant steel and its effect on the microstructure and wear properties of the wear resistant steel was investigated. The wear resistant steel was produced via direct quenching with nominal hardness of 400 HB. Gas tungsten arc welding was used for joining process. The results showed that welding led to hardness reduction, wear rate increase and also significant changes in microstructure of the heat affected zone of the wear resistant steel. According to the results, by increasing the heat input for about 9%, the hardness and wear rate of the heat affected zone was decreased 8% and increased 250%, respectively. According to the scanning electron microscopy observations the main wear mechanisms of the base metal were adhesion and abrasion. However, the wear mechanisms of the heat affected zone were mainly adhesion and delamination. By increasing the heat input, the delamination was increased significantly. }, Keywords = {Wear, Wear resistant steel, Gas tungsten arc welding, Micro-hardness.}, volume = {4}, Number = {2}, pages = {13-22}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-220-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-220-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Rabiezadeh, A. and Afsari, A.}, title = {Effect of nanoparticles addition on dissimilar joining of aluminum alloys by friction stir welding}, abstract ={The purpose of this study was to examine the effect of adding Nano particles such as Nano Carbon Tube during Friction Stir Welding (FSW) on dissimilar Al alloy joints. More specifically, both FSW and Friction Stir Processing (FSP) were performed simultaneously to investigate the effect of adding Nano particles on mechanical properties and microstructure of the weld zone for joining AA5754-H22 and AA6063-T4aluminum alloys. Reliability of the joints was tested by non-destructive tests such as visual inspection, ultrasonic, and radiography. The global mechanical behaviors of dissimilar welds were similar to that of the base material. Important losses in ductility were also reported for dissimilar welds. Microstructural evaluation of fractured surfaces indicated that ductile fracture was the major mechanism of similar and dissimilar welds. We expected that the locks for dislocation moving would improve the mechanical properties of the weld zone. Also, the friction coefficient in the two-passes welded sample was about 30% lower than the friction coefficient of the base metal. On the bases of the wear resistance of hardness and the coefficient of friction, it was concluded that the wear resistance of the surface Nano-composite produced had also increased in the stir zone.}, Keywords = {Dissimilar welding, Al alloy, CNT, Friction stir welding, wear test}, volume = {4}, Number = {2}, pages = {23-34}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-223-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-223-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Ostovar, M. and Saeid, T. and Mostafapour, A. and Emami, S.}, title = {Optimization of TIG-MIG hybrid welding of 316L austenitic stainless steel}, abstract ={In the TIG-MIG hybrid welding, higher weld efficiency and better weld quality are obtained with respect to each individual TIG and MIG welding methods. Moreover, in this method, the MIG arc is more stable in pure argon shielding gas. Therefore, in this study, the influence of TIG-MIG hybrid welding parameters on the welds appearance quality and welds depth to width ratio of a 316L austenitic stainless steel was investigated using optimum parameters of Taguchi design of experiments (DOE). Microstructure of the heat affected zone (HAZ) obtained from the hybrid welding was compared with those of each individual MIG and TIG welding techniques under equal heat-input condition. The results indicated that the most important parameter in the hybrid method to obtain the best appearance quality and the highest depth to width ratio is the distance between the two arcs. The MIG and TIG currents are the next influencing parameters. The width of HAZ and the size of constituent grains in hybrid welding with optimum parameter, were smaller than those of each individual TIG and MIG processes due to the higher associated cooling rate in the hybrid welding technique.}, Keywords = {Austenitic Stainless Steel, TIG-MIG Hybrid Welding, TIG Welding, MIG Welding.}, volume = {4}, Number = {2}, pages = {35-45}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-224-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-224-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Sadeghi, B. and Shamanian, M. and Ashrafizadeh, F. and Cavaliere, P.}, title = {Friction stir welding of Al-Al2O3 nanocomposite with bimodal size of alumina reinforcement produced by spark plasma sintering}, abstract ={Solid state joining of powder metallurgy (P/M) processed and sintered by spark plasma sintering through friction stir welding (FSW) was studied. The nanocomposites were prepared via mechanical milling followed by spark plasma sintering. The microstructural and mechanical of the joints were evaluated as a function of the different processing parameters such as rotating and advancing speeds of the tool. The achieved finding revelled that the FSW of the nanocomposites produced by P/M containing bimodal sized Al2O3 reinforcement have a working window are affected by the heat input. The joint evolution revelled that the microstructure and mechanical properties of those was related to the generated heat input during the welding. It is known that dynamic recrystallization (DRX) caused grain size refinement of aluminium into stir zone. Meanwhile, it was revealed that the pinning effect of Al2O3 nanoparticles retarded grain growth of the recrystallized grains caused by dynamic recrystallization (DRX)}, Keywords = {Aluminum matrix nanocomposite, spark plasma sintering,friction stir welding, heat input, pinning effect.}, volume = {4}, Number = {2}, pages = {47-57}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-225-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-225-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Hajitabar, A. and Naffakh-Moosavy, H.}, title = {Investigation of the influence of electron beam welding current change on the microstructure and mechanical properties of Nb-1Zr advanced alloy}, abstract ={The effect of electron beam welding current changes on the microstructure and mechanical properties of the Nb-based alloy has been investigated. The electron beam welding was applied with 4 different currents of 20, 24, 30 and 35 mA on 3mm thick plates. The aspects including different welding regions, geometry and depth of welding penetration, as well as the effect of heat input on the weldability are investigated. The mechanical properties including tensile and microhardness values of the weld was also measured. The results show that in a sample with a 30 mA welding current, the optimum conditions for the depth of penetration, weldability and the geometry of the weld are obtained. The welds showed a cellular structure, and intercellular dendrites in the central region of the weld have been caused due to microsegregations created between the cells. In HAZ, severe recrystallization and grain growth has occurred. Because of the high thermal conductivity of niobium, the HAZ size is relatively large. Based on the 3D Rosenthal’s equation, the recrystallization temperature of alloy was calculated as 713 °C. It is observed that as G × R increases, the grain size in the central line of the weld decreases. The hardness profile shows that the hardness of the weld zone and the HAZ is significantly less than that of the base metal due to elimination of work hardening effect. The tensile strength of the weld for a sample with a current of 30 mA was 281MPa, which is 53% of the tensile strength of the base metal and the weld was broken from the HAZ.}, Keywords = {Electron beam welding, advanced alloy Nb-1Zr, welding current, microstructure, weldability, mechanical properties.}, volume = {4}, Number = {2}, pages = {59-70}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-226-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-226-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {KhodaiDelouei, I. and Sabet, H. and AboueiMehrizi, V.}, title = {The effect of transvers speeds on microstructure and mechanical properties of the AA2024 to AA6061 joint welded by FSW}, abstract ={Friction  Stir Welding  is one of the solid-state processes and today it has been used to join different types of materials. Friction stir welding does not have many problems and limitations due to melting and solidification of weld metal and by controlling its variables, the microstructure and desired mechanical properties can be achieved at the joint. Recently, in most industrial areas, due to its lightness and energy saving, much attention has been paid to the joining of aluminum alloys. The present study investigates the microstructure and evaluation of mechanical properties of friction stir welding in AA2024 and AA6061butt welds. A cylindrical threaded tool was used to join 5 mm thick plates at rotational speeds of 800, 1000 and 1200 rpm and traverse speeds of 30, 50, 70, 90 and 110 mm / min. In order to perform the necessary investigations, metallurgical observations were performed by optical microscope and scanning electron microscope equipped with a chemical analysis system of the elements, as well as mechanical tests of tensile strength and micro hardness. The results showed that the difference between the two alloys causes hardness variations in the nugget zone and a large hardness drop at the transition between the zone composed of both alloys and the 6061 zone. By increasing the traverse speed from 30 to 110 mm / min at constant rotational speeds of 800, 1000 and 1200 rpm, due to reduced input heat, the grain size decreases and the hardness and strength increase. Also, the highest tensile strengths and hardness were 221.6 Mpa and 111.05 Vickers, respectively, for a sample welded at a rotational speed of 1000 rpm and a traverse speed of 110 mm / min.}, Keywords = {Friction Stir Welding, Aluminum alloy 2024, Aluminum alloy 6061, Traverse Speed, Rotational Speed.}, volume = {4}, Number = {2}, pages = {71-86}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-227-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-227-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Sabokrouh, M. and Saroghi, M.}, title = {Experimental determination of normalizing effect on mechanical and metallurgical properties of HSLA API X65 multi-pass girth weld}, abstract ={High strength low alloy steels are widely used in gas industry, so shield metal arc welding in pipelines to transport natural gas from Iran is of great importance. For experimental investigation of seam weld and integrity of girth weld, destructive and non-destructive tests are required. In this article the effects of normal heat treatment on properties of multi pass welding in different situations (6-7:30 , 7:30-9 , 9-10:30 , 10:30-12) with 36 in outside diameter is evaluated by chemical,  metallography, tensile, toughness and hardness. The result shows that normalizing increases ferrite ratio in root pass and weld cap pass respectively 24 and 6 percent than base steel. Also the increase rate of ferrite in root, hot, filler, and the cap pass are respectively 32, 14, 12 and 7 percent before than normalizing. The elongation weld of was increased ratio than before the heat treatment in base metal respectively 65 and 5 percent. The impact energy alignment to weld (9-10:30) had a rate of 70 percent increase before the heat treatment. The increase rate of C, V and Ti in the weld zone according to base metal in situation of 6-7:30 are respectively 0.01, 0.003 and 0.005.}, Keywords = {normalizing, high strength low alloy steel, multi pass girth weld, natural gas pipeline, API X65}, volume = {4}, Number = {2}, pages = {87-98}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-228-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-228-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {ShaikhMeiabadi, M.Saleh and Kazerooni, A. and Moradi, M.}, title = {Experimental and Numerical Investigation of Laser Assisted PC to Polycarbonate Welding}, abstract ={Laser welding is a novel method for direct joining of metals and polymers, which leads to a mechanical and chemical bond between metal and polymer. In this study, feasibility of dissimilar joining between St12 and polycarbonate is studied theoretically. Then, the ND: YAG laser is implemented to join St12 and Polycarbonate. Empirical results indicate creation of a joint between St12 and polycarbonate. In order to conduct thermomechanical analysis of the welding process, the finite element model has been developed by Abaqus software. In addition, the cylindrical-involution-normal (CIN) heat source model was used to describe the laser power distribution and FORTRAN software has been used to define the thermal model in welding simulation. Comparison of experimental and simulation results shows that the finite element model is capable of predicting weld width, and therefore the results of the finite element model are verified. Therefore, the finite element model is used to predict residual stresses. The results disclose that dissimilar bonding creates residual tension stresses on the metal surface and compressive residual stresses on the polymer surface.    }, Keywords = {Dissimilar joint, Laser welding, St12, Polycorbonate, Thermomechanical analysis.}, volume = {4}, Number = {2}, pages = {99-109}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-229-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-229-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} } @article{ author = {Rasouli, I. and Rafiei, M.}, title = {Evaluation of dissimilar joint properties of AISI316 to AISI430 stainless steels produced by GTAW}, abstract ={In this research, microstructure and mechanical properties of AISI316 to AISI430 dissimilar joint were investigated. For this purpose, GTAW process using ER316L and ER2209 filler metals with diameter of 2.4 mm was used. The microstructure and fracture surface of the welded samples were characterized by optical microscopy and scanning electron microscopy. Also the mechanical properties of the welded samples were evaluated by tension, impact and microhardness tests. It was found that the microstructure of the welded sample with ER316L filler metal contained Widmanstatten austenite with inter-dendritic and lathy ferrites. Also, in the welded sample with ER2209 filler metal, Austenite phase in ferrite matrix was seen. In tension test, all samples were fractured from AISI430 side of the joint in a ductile manner. ER2209 weld metal indicated low impact energy of about 27 J, while ER316L weld metal indicated higher impact energy of about 43 J. The fracture surface in both welded samples indicated brittle fracture mode. The microhardness of the weld metal of the welded sample with ER316L filler metal was higher than the welded sample with ER2209 filler metal due to the presence of alloying elements, proper distribution of delta ferrite and finer microstructure.}, Keywords = {Dissimilar joint, AISI316 steel, AISI430 steel, Mechanical properties, Microstructure, Weld metal.}, volume = {4}, Number = {2}, pages = {111-126}, publisher = {Iranian Institute of Welding and Non Destructive Testing}, url = {http://jwsti.iut.ac.ir/article-1-230-en.html}, eprint = {http://jwsti.iut.ac.ir/article-1-230-en.pdf}, journal = {Journal of Welding Science and Technology of Iran}, issn = {2476-583X}, eissn = {2676-6787}, year = {2019} }