2024-03-28T23:04:18+04:30 http://jwsti.iut.ac.ir/browse.php?mag_id=5&slc_lang=fa&sid=1
5-156 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 The possibility of the TLP bonding between UNS S32750 and AISI 304 R. Abdolvand M. Atapour M. Shamanian A. Allafchian Transient liquid phase bonding of  UNS S32750 super duplex stainless steel to AISI 304 austenitic stainless steel using BNi-2 interlayer was carried out at 1050 oC for 45 min. Microstructure analyses of the joint were carried out using optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Microhardness indentation and shear strength test were performed to assess mechanical behavior of the joint. No eutectic contents was seen at the joint and thus Isothermal solidification was completed at 45 min bonding time. The shear strength of the joint was about 0.7 of duplex stainless steel shear strength. Froctographic studies revealed that the fracture mode was completely ductile in the case of the joint made at bonding time of 45 min. Transient liquid phase Duplex stainless steel Austenitic stainless steel Dissimilar joint. 2018 1 01 1 8 http://jwsti.iut.ac.ir/article-1-156-en.pdf
5-157 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 Analysis of Failure Caused by In-service Welding in anX52 Gas Pipeline A. Farzadi S. Sanaei In the research presented in this paper, a failure analysis were carried out to identify causes of an incident, which had taken place after an operation to repair a leak in an interstate natural gas pipeline. In this operation, a partial encirclement reinforcement (patch) was welded to the carrier pipe according to an available hot taping procedure, while gas was flowing in the pipeline. The failure analysis commenced with preliminary steps of gathering of background data regarding the repair operation and then several samples were extracted for macroscopic and microscopic metallurgical examinations. In addition to fractographic analyses of fracture surfaces, pipe material was examined because the pipeline had been in service for prolonged period and there was not any official material information available. The analyses disclosed that hydrogen-assisted cracking, wrong design of branch connection, paint coating and pipeline operating conditions were major factors contributing to the failure.   Toe crack Hydrogen-assisted cracking Metallurgical failure analysis Branch connection reinforcement Joule-Thomson effect “Live” welding Operating conditions. 2018 1 01 9 19 http://jwsti.iut.ac.ir/article-1-157-en.pdf
5-158 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 Measuring of Residual Stress in TIG Welding of the 304 Stainless Steel by Ultrasonic Method A. Parvaresh H. Sabet M. Roohnia In this research, the effect of different welding parameters on residual stress and microstructure of the weld region, as well as the comparison of two methods of measuring residual stress using critical fracture longitudinal wave method and preformation method have been investigated. For this purpose, the taguchi DOE methodology is used as a statistical method to optimize four parameters of pulse current, base current, and pulse on time% and pulse frequency to minimize longitudinal residual stresses in austenite 304 AISI stainless steel. After welding, stress measurements were performed using two methods critical fracture longitudinal and perforation, and hardness, tensile and OM tests were performed on the specimens. The tests results show that at all levels of the pulse parameters arranged with the standard L9 Taguchi array, the incident heat input is irrefutable and the effect of this parameter is move then 50%. The optimum conditions obtained while the highest frequency level should be considered. The general trend is achieved from the residual stress measurement charts is consistent with the logic of stress distribution in both methods. Sample number 1 with stress equivalent to 232 MPa and sample number 9 with stress of MPa 126 in ultrasonic method with frequency 4 MHz have the highest and lowest stress among different samples, respectively. The size of the coaxial grains weld was directly related to the incoming heat, so that the least amount of coaxial grains in the welding center was related to specimens NO. 3 and 9 with grain size of 8 µm and 9 µm, which in these samples had the lowest amount of welding heat is measured. The samples 1 and 4 with HV 128 and HV 144 hardness and MPa 633 and MPa 639 have the least hardness and tensile strength and the highest strength and hardness of sampled 3 and 9 with 166 and 161 hardness and tensile strength MPa 703 and MPa 695.   Residual Stress Critical Failure Longitudinal Wave Method Variance Analysis TIG Welding Austenitic Stainless Steel. 2018 1 01 20 32 http://jwsti.iut.ac.ir/article-1-158-en.pdf
5-159 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 Using a New Contact Resistance Model for Investigating Mechanical Properties of Hastelloy X Welded Joints in Small Scale Resistance Spot Welding M. Atashparva M. Hamedi Nowadays, due to the need for miniaturization, small scale resistance spot welding is of interest. The key factor that determines the nugget size is contact resistance. In this paper a new equation is provided to calculate the electrical contact resistance. The model can predict the high temperature contours and the nugget configuration efficiently. Also, a set-up was constructed to verify the model and investigate the effects of parameters on the mechanical properties of Hastelloy X welded joints. DOE analysis is done to recognize the effect of parameters on the nugget diameter, maximum load, and nugget height. It was concluded that the size of the nugget enlarges by increasing welding current and time. The nugget diameter decreases with increase of force. Small scale resistance spot welding Electrical contact resistance Nugget diameter Design of experiments Hastelloy X 2018 1 01 33 48 http://jwsti.iut.ac.ir/article-1-159-en.pdf
5-68 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 resistance spot welding of nanostructured Al 2024 alloy and Evaluation of mechanical properties Weldment payam gheysari payamgheisari1369@gmail.com fathallah karimzadeh karimzadeh_f@cc.iut.ac.ir ahmad rezaeian a.rezaeian@cc.iut.ac.ir amin shahsavari amin.shahsavari@ma.iut.ac.ir In this research in order to improve the mechanical properties of Aluminium alloy 2024, nanostructure Aluminum sheets were first produced by Cryorolling process and then was welded by resistance spot welding method. For this purpose, the samples solution treated at 495˚C for 55 minute and subsequently cryorolled up to 85% reduction in thickness. For obtaining simultaneous strength and ductility, the cryorolled sheets were then subjected to aged. In this regard the produced samples were then resistance spot welded with different welding parameters, including welding current 60 to 105 KA, electrode force of 3 KN, and welding time of 0.1 s. The highest tensile shear peak load was obtained through welding with 95 KA current. Al 2024 alloy nanostructure Cryorolling Resistance spot welding Mechanical properties 2018 1 01 49 57 http://jwsti.iut.ac.ir/article-1-68-en.pdf
5-66 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 The stress concentration of In718 superalloy after friction welding and compare with Mar-M247 and In718 welded joints Seyed Rahim Kiahosseini rkiahoseyni@yahoo.com Mostafa teymoori teymouri.uast@gmail.com Friction stir welding (FSW) is a new method that the joining is carried out by friction between two metals and heat creation. The stress concentration phenomena in welded joint cause the stress increasing in welded zone. In this research, modeling and analysis of similar junction of IN718 and Mar-M247 and non-similar junction of IN718-Mar-M247 superalloys were performed by ANSYS Software and finally the stress concentration factors of welded samples were calculated. The stress concentration factor of similar and non-similar of junctions was assessed and compared with reported experimental data in the literatures. The results showed that, the mean stress concentration factor for similar junction of Mar-M247 and IN718 superalloys are 1.566 and 1.63 respectively and for non-similar junction is equal to 1.52. Paste zone superalloy degrees of freedom ANSYS software Stress Concentration. 2018 1 01 58 67 http://jwsti.iut.ac.ir/article-1-66-en.pdf
5-162 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 Investigation of the mechanical properties of cold roll welded Brass and IF steelproduced by cold roll bonding process Cold roll bonding (CRB) is a solid state welding process, where the bonding is established by compressive plastic deformation of the metals. This process is applicable for a large number of materials. In addition, materials that cannot be bonded by traditional fusion-based processesmight be bonded by CRB process. In this research, cold roll welding of brass and IF steel was studied .The effects of process parameters such as reduction of thickness, pre-rolling annealingconditions and surface roughness on the mechanical propertiesof welded strips were investigated. The peeling and shear punch testswere used to investigate the mechanical properties of welded samples .It was observed that the bond andshear strengthswere enhanced by increasing the reduction and surface roughness. Also, annealing treatment before the CRB process increased the bond strength anddecreasedthe shear strength. Finally, optical and scanning electron microscopes were used to evaluate the fracture surfaces of the tensile and peelingtest specimens. Cold roll bonding Solid state welding mechanical properties Bond strength Shearstrength 2018 1 01 68 78 http://jwsti.iut.ac.ir/article-1-162-en.pdf
5-163 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 Optimization of FSW parameters for mechanical properties of Nano/UFG Aluminum- scandium alloys by using design of experiment method M. Yousefieh M. Tamizifar S.M.A. Boutorabi E. Borhani In the present research, the parameters of FSW process were optimized for the mechanical properties of thin aluminum- scandium alloys by a design of experiment (DOE) technique. The optimum conditions providing the highest mechanical properties were found by this method. Among the three factors and three levels tested, it was concluded that the tool rotational speed had the most significant effect on the mechanical properties and the travel speed had the next most significant effect. The effect of tool tilt angle was less important when compared to the other factors. The EBSD results demonstrated a recrystallized equi axial structure and the existence of a mixture of B and Ccomponents in the weld nugget. Friction stir welding Al-Sc alloys Mechanical properties Microstructure Design of experiment Texture. 2018 1 01 79 89 http://jwsti.iut.ac.ir/article-1-163-en.pdf
5-164 2024-03-28 10.1002
Journal of Welding Science and Technology of Iran JWSTI 2476-583X 2676-6787 2018 3 2 On the microstrctral and machanical properties of similar TLP bonding of Inconel 600 superalloy sheet A. Khorram A. Davoodi Jamalooei A. Jafari In this study, microstructural evaluation and mechanical properties of similar TLP bonded of Inconel 600 by using of BNi-2 interlayer were investigated. The bonding tests were carried out at 1050°C and 1100°C for 5-45 min which homogenization treatment was performed on the best of the bonded samples. Results showed that Ni-B eutectic compound was formed in the a-thermally solidification zone (ASZ) of the bonded sample at 1050°C. In addition to existence of the Ni-B compound, Cr-B was observed in the ASZ of the bonded sample at 1100°C. Ni-B and Ni-Cr-B were formed in the diffusion affected zone (DAZ). TLP bonded sample at 1050°C for 45min including discontinuous areas of ASZ in isothermal solidification zone (ISZ) was the best bonded sample. Homogenization process was carried out on this sample caused to elimination of the eutectic compounds, completely. Mechanical investigation revealed that due to existence of the intermetallic compounds in the ASZ and DAZ, value of hardness for this region were about 510 and 311 HV, respectively. Whit elimination of the intermetallic compounds by performing of homogenization treatment, mechanical properties of the boding region were improved.   Transient Liquid Phase Inconel 600 BNi-2 Mechanical properties. 2018 1 01 90 104 http://jwsti.iut.ac.ir/article-1-164-en.pdf