scholarly journals Experimental and Numerical Simulation of Girth Welded Joints of Dissimilar Metals in Clad Pipes

2018 ◽  
Vol 28 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Bridget Kogo ◽  
Bin Wang ◽  
Luiz C Wrobel ◽  
Mahmoud Chizari
Keyword(s):  
Numerical Simulation ◽  
Welded Joints ◽  
Dissimilar Metals

Estimation of Some Mechanical Properties for Similar & Dissimilar Welded Joints

2014 ◽  
Vol 2 (1) ◽  
pp. 59-76
Author(s):  
Abdullah Daie'e Assi
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Austenitic Stainless Steel ◽  
Base Metal ◽  
Welded Joints ◽  
Plate Thickness ◽  
Low Carbon Steel ◽  
Dissimilar Metals ◽  
Low Carbon ◽  
Steel Type

This research deals with the choice of the suitable filler metal to weld the similar and dissimilar metals (Low carbon steel type A516 & Austenitic stainless steel type 316L) under constant conditions such as, plate thickness (6 mm), voltage (78 v), current (120 A), straight polarity. This research deals with three major parts. The first parts Four types of electrodes were used for welding of dissimilar metals (C.St A516 And St.St 316L) two from mild steel (E7018, E6013) and other two from austenitic stainless steel (E309L, E308L) various inspection were carried out include (Visual T., X-ray T., δ- Ferrite phase T., and Microstructures T.) and mechanical testing include (tensile T., bending T. and micro hardness T.) The second parts done by used the same parameters to welding similar metals from (C.St A516) Or (St.St 316L). The third parts deals with welding of dissimilar weldments (C.St And St.St) by two processes, gas tungsten are welding (GTAW) and shielded metal are welding (SMAW).        The results indicated that the spread of carbon from low carbon steel to the welding zone in the case of welding stainless steel elect pole (E309L) led to Configuration Carbides and then high hardness the link to high values ​​compared with the base metal. In most similar weldments showed hardness of the welding area is  higher than the hardness of the base metal. The electrode (E309L) is the most suitable to welding dissimilar metals from (C.St A516 With St.St 316L). The results also showed that the method of welding (GTAW) were better than the method of welding (SMAW) in dissimilar welded joints (St.St 316L with C.St A516) in terms of irregular shape and integrity of the welding defects, as well as characterized this weldments the high-lift and resistance ductility good when using the welding conditions are similar.

Finite Element Analyses of Residual Stresses in Typical Welded Joints Used in Nuclear Power Plants and Comparisons With Experiments

2010 ◽  
Author(s):  
Dean Deng ◽  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Nuclear Power ◽  
Power Plants ◽  
Butt Joint ◽  
Welding Residual Stress ◽  
Dissimilar Metal ◽  
Water Reactors

Recent discoveries of stress corrosion cracking (SCC) at nickel-based metals in pressurized water reactors (PWRs) and boiling water reactors (BWRs) have raised concerns about safety and integrity of plant components. It has been recognized that welding residual stress is an important factor causing the issue of SCC in a weldment. In this study, both numerical simulation technology and experimental method were employed to investigate the characteristics of welding residual stress distribution in several typical welded joints, which are used in nuclear power plants. These joints include a thick plate butt-welded Alloy 600 joint, a dissimilar metal J-groove set-in joint and a dissimilar metal girth-butt joint. First of all, numerical simulation technology was used to predict welding residual stresses in these three joints, and the influence of heat source model on welding residual stress was examined. Meanwhile, the influence of other thermal processes such as cladding, buttering and heat treatment on the final residual stresses in the dissimilar metal girth-butt joint was also clarified. Secondly, we also measured the residual stresses in three corresponding mock-ups. Finally, the comparisons of the simulation results and the measured data have shed light on how to effectively simulate welding residual stress in these typical joints.

Numerical simulation of the effect of ultrasonic impact treatment on welding residual stress

2021 ◽  
pp. 2150175
Author(s):  
Tao Mo ◽  
Jingqing Chen ◽  
Pengju Zhang ◽  
Wenqian Bai ◽  
Xiao Mu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Compressive Stress ◽  
Welded Joints ◽  
Welding Process ◽  
Residual Compressive Stress ◽  
Welding Residual Stress ◽  
304 Stainless Steel ◽  
Residual Tensile Stress ◽  
Ultrasonic Impact Treatment

Ultrasonic impact treatment (UIT) is an effective method that has been widely applied in welding structure to improve the fatigue properties of materials. It combines mechanical impact and ultrasonic vibration to produce plastic deformation on the weld joints surface, which introduces beneficial compressive residual stress distribution. To evaluate the effect of UIT technology on alleviating the residual stress of welded joints, a novel numerical analysis method based on the inherent strain theory is proposed to simulate the stress superposition of welding and subsequent UIT process of 304 stainless steel. Meanwhile, the experiment according to the process was carried out to verify the simulation of residual stress values before and after UIT. By the results, optimization of UIT application could effectively reduce the residual stress concentration after welding process. Residual tensile stress of welded joints after UIT is transformed into residual compressive stress. UIT formed a residual compressive stress layer with a thickness of about 0.13 mm on the plate. The numerical simulation results are consistent with the experimental results. The work in this paper could provide theoretical basis and technical support for the reasonable evaluation of the ultrasonic impact on residual stress elimination and mechanical properties improvement of welded joints.

Numerical simulation of the joining interface of dissimilar metals in vaporizing foil actuator welding: Forming mechanism and factors

2020 ◽  
Vol 60 ◽  
pp. 654-665
Author(s):  
Zhenghua Meng ◽  
Mengyuan Gong ◽  
Wei Guo ◽  
Wei Liu ◽  
Shangyu Huang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Dissimilar Metals ◽  
Forming Mechanism

scholarly journals Experimental Research and Numerical Simulation of Weld Repair with High Energy Spark Deposition Method

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 980 ◽  
Author(s):  
Yingjie Zhang ◽  
Kai Yang ◽  
Jianping Zhao
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Residual Stress ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
High Energy ◽  
Repair Welding ◽  
Repair Processes ◽  
Repair Technology ◽  
Surface Repair

For long-serviced pressure equipment that is under severe working conditions such as a high temperature, high pressure, and corrosion, the material properties and structure will be unavoidably damaged or degraded, especially cracks and other damages at key positions such as welded joints, which seriously threaten the safe operation of the equipment. In order to promote the sustainable development of industries such as the chemical and petrochemical industries, remanufacturing technology has emerged worldwide, and various surface repair processes have also rapidly developed. As an important branch of surface repair technology, the high energy spark deposition (HESD) process is a new pulse cold welding repair technology developed from electro-spark deposition, which combines the advantages of multiple surface repair processes. The HESD process has the characteristics of a smaller heat affected zone and lower welding residual stress. It is a new type of repair method that is worthy of popularization and application. The process has been initially applied in the fields of surface modification and die steel repair. In this paper, the application of the HESD process to the repair of welded joints was introduced, the mechanical properties of the joints and the residual stress distribution after welding were analyzed, and the feasibility of HESD as a repair welding method for pressure structures was discussed. First, a numerical simulation of the temperature and stress field of HESD was proposed by using ABAQUS and the related subprograms, and the validity of the simulation results was verified by the residual stress test with the indentation strain method. Due to the precise control of the heat and pulse discharge working mode, the heat-affected zone and deformation caused by the HESD were extremely small, and the residual stress that was generated was low and only concentrated on the repair welding seam. Second, according to the numerical simulation and the test results of the mechanical properties of the welded joint, the optimal repair welding process parameters were obtained through the orthogonal experiment: peak current 45 A, pulse width 90 ms, and output voltage 10 V.

scholarly journals Numerical simulation and experimental investigation of the damage behavior on electron beam welded joints

2011 ◽  
Vol 10 ◽  
pp. 875-880 ◽  
Author(s):  
H.Y. Tu ◽  
S. Schmauder ◽  
U. Weber ◽  
Y. Rudnik ◽  
V. Ploshikhin
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
Electron Beam ◽  
Welded Joints ◽  
Damage Behavior
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