1 2476-583X Iranian Institute of Welding and Non Destructive Testing 221 Special 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 Gholami M. Mostaan H. Sonboli A. 1 1 2019 4 2 1 12 20 02 2019 20 02 2019 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.
220 Special Gas tungsten arc welding of direct quenched wear resistant steel to plain carbon steel and evaluation of its microstructure and wear properties Vanaee M. Ardestani M. Abbasi A. 1 1 2019 4 2 13 22 20 02 2019 20 02 2019 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.  223 Special Effect of nanoparticles addition on dissimilar joining of aluminum alloys by friction stir welding Rabiezadeh A. i Afsari A. j i Department of Materials Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran. j Department of Mechanical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran 1 1 2019 4 2 23 34 04 03 2019 04 03 2019 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. 224 Special Optimization of TIG-MIG hybrid welding of 316L austenitic stainless steel Ostovar M. k Saeid T. l Mostafapour A. m Emami S. n k Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. l Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. m Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. n Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran. 1 1 2019 4 2 35 45 04 03 2019 04 03 2019 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. 225 Special Friction stir welding of Al-Al2O3 nanocomposite with bimodal size of alumina reinforcement produced by spark plasma sintering Sadeghi B. o Shamanian M. p Ashrafizadeh F. Cavaliere P. o Department of Material Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran p Department of Material Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran Department of Material Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran Department of Innovation Engineering, University of Salento, Lecce, Italy 1 1 2019 4 2 47 57 04 03 2019 04 03 2019 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) 226 Special Investigation of the influence of electron beam welding current change on the microstructure and mechanical properties of Nb-1Zr advanced alloy Hajitabar A. Naffakh-Moosavy H. 1 1 2019 4 2 59 70 04 03 2019 04 03 2019 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. 227 Special The effect of transvers speeds on microstructure and mechanical properties of the AA2024 to AA6061 joint welded by FSW Khodai Delouei I. Sabet H. Abouei Mehrizi V. Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj , Iran Department of Materials Engineering, Karaj Branch, Islamic Azad University, Karaj , Iran Advanced Materials Engineering Research Center, KarajBranch, IslamicAzad University, Karaj , Iran. 1 1 2019 4 2 71 86 04 03 2019 04 03 2019 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. 228 Special Experimental determination of normalizing effect on mechanical and metallurgical properties of HSLA API X65 multi-pass girth weld Sabokrouh M. Saroghi M. Faculty of Engineering, Mahallat Institute of Higher Education, Mahallat, Iran. Faculty of Engineering, Islamic Azad University of Arak, Arak, Iran 1 1 2019 4 2 87 98 04 03 2019 04 03 2019 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. 229 Special Experimental and Numerical Investigation of Laser Assisted PC to Polycarbonate Welding Shaikh Meiabadi M.Saleh Kazerooni A. Moradi M. Department of Mechanical Engineering, Faculty of Engineering, SRTT University, Tehran, Iran Department of Mechanical Engineering, Faculty of Engineering, SRTT University, Tehran, Iran Department of Mechanical Engineering, Malayer University, Malayer, Iran 1 1 2019 4 2 99 109 04 03 2019 04 03 2019 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.     230 Special Evaluation of dissimilar joint properties of AISI316 to AISI430 stainless steels produced by GTAW Rasouli I. Rafiei M. 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. 1 1 2019 4 2 111 126 04 03 2019 04 03 2019 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.