Geometrical and Welding Conditions on Through-Thickness Residual Stress in Primary Piping of Girth Welded Joints

2008 ◽  
Vol 580-582 ◽  
pp. 573-576 ◽  
Author(s):  
Jinya Katsuyama ◽  
Masahito Mochizuki ◽  
Hiroaki Mori ◽  
W. Asano ◽  
Gyu Baek An ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Three Dimensional ◽  
Finite Element Analyses ◽  
Welding Zone ◽  
Butt Welding ◽  
Welding Joints

Recently, stress corrosion cracking (SCC) of primary piping of stainless steel has been observed. SCC is considered to initiate and progress at near the welding zone in butt-welded pipes, because of the tensile residual stress introduced by welding. In present work, three-dimensional and axisymmetric thermo-elastic-plastic finite element analyses have been carried out, in order to clarify the effect of geometrical and welding conditions on through-thickness residual stress. In particular, butt-welding joints of SUS316L pipes have been examined. The residual stress was simulated by three-dimensional and axisymmetric models and the results were compared and discussed in detail.

Parametric FEM Evaluation of Residual Stress by Circumferential Welding for Austenitic Stainless Steel

2005 ◽  
Author(s):  
Jinya Katsuyama ◽  
Masahito Mochizuki ◽  
Ryota Higuchi ◽  
Masao Toyoda
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Corrosion Cracking ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Welding Zone ◽  
Butt Welding ◽  
Plastic Analysis

Recently, stress corrosion cracking (SCC) of core internals and/or recirculation pipes of austenite stainless steel has been observed. SCC is considered to occur and progress near the welding zone because of the weld tensile residual stress. In the present work, thermo-elastic-plastic analysis of the residual stress was performed in order to clarify the effect of several parameters (diameter, thickness, number of multilayer welding) in the circumferential welding zone. Butt welding joint of SUS316L-pipes was examined. The residual stress was calculated by three dimensional-model and axisymmetric model and the results were compared and discussed in detail.

Effect of Geometric and Welding Conditions on Through-Thickness Residual Stress

2006 ◽  
Author(s):  
Masahito Mochizuki ◽  
Jinya Katsuyama ◽  
Masao Toyoda
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Stainless Steel ◽  
Three Dimensional ◽  
Axially Symmetric ◽  
Welding Zone ◽  
Element Analysis ◽  
Butt Welding ◽  
Inner Surface ◽  
Welding Joints

Recently, stress corrosion cracking (SCC) of core internals and/or recirculation pipes of austenite stainless steel (SUS316L) has been observed. SCC is considered to occur and progress at near the inner surface of the welding zone in butt-welded pipes, because of the tensile residual stress introduced by welding. In present work, three-dimensional and axisymmetric thermo-elastic-plastic finite element analysis have been carried out, in order to clarify the effect of geometric and welding conditions in circumferential welding zone on the residual stress. In particular, butt-welding joints of SUS316L-pipes have been examined. The residual stress was simulated by three-dimensional and axially symmetric models and the results were compared and discussed in detail.

Effect of Ultrasonic Impact Treatment on the Stress Corrosion Cracking of 304 Stainless Steel Welded Joints

2008 ◽  
Author(s):  
Gang Ma ◽  
Xiang Ling
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
304 Stainless Steel ◽  
Ultrasonic Impact Treatment

High tensile weld residual stress is an important factor contributing to stress corrosion cracking (SCC). Ultrasonic impact treatment (UIT) can produce compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the present work, X-ray diffraction method was used to obtain the distribution of residual stress induced by UIT. The results showed that UIT could cause a large compressive residual stress up to 325.9MPa on the surface of the material. A 3D finite element model was established to simulate the UIT process by using a finite element software ABAQUS. The residual stress distribution of the AISI 304 stainless steel induced by UIT was predicted by finite element analysis. In order to demonstrate the improvement of the SCC resistance of the welded joints, the specimens were immersed in boiling 42% magnesium chloride solution during SCC testing, and untreated specimen cracked after immersion for 23 hours. In contrast, treated specimens with different coverage were tested for 1000 hours without visible stress corrosion cracks. The microstructure observation results revealed that a hardened layer was formed on the surface and the initial coarse-grained structure in the surface was refined into ultrafine grains. The above results indicate that UIT is an effective approach for protecting weldments against SCC.

Effect of Ultrasonic Impact Treatment on the Stress Corrosion Cracking of 304 Stainless Steel Welded Joints

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Xiang Ling ◽  
Gang Ma
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Welded Joints ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
304 Stainless Steel ◽  
Ultrasonic Impact Treatment

High tensile weld residual stress is an important factor contributing to stress corrosion cracking (SCC). Ultrasonic impact treatment (UIT) can produce compressive stresses on the surface of welded joints that negate the tensile stresses to enhance the SCC resistance of welded joints. In the present work, X-ray diffraction method was used to obtain the distribution of residual stress induced by UIT. The results showed that UIT could cause a large compressive residual stress in access of 300 MPa on the surface of the material. A 3D finite element model was established to simulate the UIT process by using the finite element software ABAQUS. The residual stress distribution of the AISI 304 stainless steel induced by UIT was predicted by finite element analysis. In order to demonstrate the improvement of the SCC resistance of the welded joints, the specimens were immersed in boiling 42% magnesium chloride solution during SCC testing, and untreated specimen cracked after immersion for 23 h. In contrast, treated specimens with different impact duration were tested for 1000 h without visible stress corrosion cracks. The microstructure observation results revealed that a hardened layer was formed on the surface and the initial coarse-grained structure in the surface was refined into ultrafine grains. The above results indicate that UIT is an effective approach for protecting weldments against SCC.

Evaluation of Residual Stresses in Small Diameter Stainless Steel Pipe Welds by Two-Dimensional and Three-Dimensional Finite Element Analyses

2014 ◽  
Author(s):  
Francis H. Ku ◽  
Trevor G. Hicks ◽  
William R. Mabe ◽  
Jason R. Miller
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Steel Pipe ◽  
3D Analysis ◽  
Two Dimensional ◽  
Finite Element Analyses ◽  
Stainless Steel Pipe

Two-dimensional (2D) and three-dimensional (3D) weld-induced residual stress finite element analyses have been performed for 2-inch Schedule 80 Type-304 stainless steel pipe sections joined by a multi-layer segmented-bead pipe weld. The analyses investigate the similarities and differences between the two modeling approaches in terms of residual stresses and axial shrinkage induced by the pipe weld. The 2D analyses are of axisymmetric behavior and evaluate two different pipe end constraints, namely fixed-fixed and fixed-free, while the 3D analysis approximates the non-axisymmetric segmented welding expected in production, with fixed-free pipe end constraints. Based on the results presented, the following conclusions can be drawn. The welding temperature contour results between the 2D and 3D analyses are very similar. Only the 3D analysis is capable of simulating the non-axisymmetric behavior of the segmented welding technique. The 2D analyses yield similar hoop residual stresses to the 3D analysis, and closely capture the maximum and minimum ID surface hoop residual stresses from the 3D analysis. The primary difference in ID surface residual stresses between the 2D fixed-fixed and 2D fixed-free constraints cases is the higher tensile axial stresses in the pipe outside of the weld region. The 2D analyses under-predict the maximum axial residual stress compared to the 3D analysis. The 2D ID surface residual stress results tend to bound the averaged 3D results. 2D axisymmetric modeling tends to significantly under-predict weld shrinkage. Axial weld shrinkage from 3D modeling is of the same magnitude as values measured in the laboratory on a prototypic mockup.

Effect of Welding Conditions on Residual Stress and Stress Corrosion Cracking Behavior at Butt-Welding Joints of Stainless Steel Pipes

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Jinya Katsuyama ◽  
Tohru Tobita ◽  
Hiroto Itoh ◽  
Kunio Onizawa
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Heat Input ◽  
Growth Behavior ◽  
Corrosion Cracking ◽  
Welding Parameters ◽  
Butt Welding ◽  
Welding Joints

Stress corrosion cracking (SCC) in Type 316 L low-carbon austenitic stainless steel recirculation pipes have been observed near butt-welding joints. These SCC in Type 316 L stainless steel grow near the welding zone mainly because of the high tensile residual stress caused by welding. Therefore, for SCC growth analysis, it is important to assess the residual stress caused by welding of stainless steel piping. In the present study, which is focused on the scatters of welding parameters such as heat input and welding speed, these values were measured experimentally by fabricating a series of butt-welded specimens of Type 316 pipes. The distribution and scatter of residual stress were also measured by stress relief and X-ray diffraction methods. The effects of welding parameters on residual stress distribution have been evaluated through welding simulations based on finite-element analysis using three-dimensional and axisymmetric models. Parametric analyses were also performed, while taking into account the variation of some welding parameters based on the experiments. SCC growth behavior was calculated using simulated residual stress distributions and applying a procedure in the fitness-for-service code. It was clearly shown that the uncertainties on welding heat input and speed have strong influences on SCC growth behavior because residual stress is also affected by the scatter of these welding parameters.

scholarly journals Using Welding Simulation and Ultrasonic Method to Evaluate Residual Stress in Stainless Steel Welded Plates

2012 ◽  
Author(s):  
Yashar Javadi ◽  
Mohammadreza Hadizadeh Raeisi ◽  
Hamed Salimi Pirzaman ◽  
Mehdi Ahmadi Najafabadi
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Acoustic Waves ◽  
Stress Measurement ◽  
Bulk Material ◽  
Three Dimensional ◽  
Ultrasonic Waves ◽  
Welding Simulation

When a material is under mechanical load, the stresses change the velocity of acoustic waves because of acoustoelastic effect. This property can be employed for stress measurement in the material itself when the stress concerns the surface of the material, or in the bulk material. This technique involves with critically refracted longitudinal waves that propagate parallel to the surface, i. e. LCR waves. This paper presents a three dimensional thermo-mechanical analysis to evaluate welding residual stresses in plate-plate joint of AISI stainless steel 304L. After finite element simulation, the residual stresses were evaluated by LCR ultrasonic waves. This paper introduces a combination of “Finite Element Welding Simulation” and “Ultrasonic Stress Measurement using the LCR Wave” which is called as “FELcr”. The capabilities of FELCR in residual stress measurement are confirmed here. It has been shown that predicted residual stress from three dimensional FE analyses is in reasonable agreement with measured residual stress from LCR method.

The Simulation of Residual Stress for Stud Welding and Establishment of Strength Estimating Model

2008 ◽  
Vol 575-578 ◽  
pp. 816-820 ◽  
Author(s):  
Guang Tao Zhou ◽  
Xue Song Liu ◽  
Guo Li Liang ◽  
Pei Zhi Liu ◽  
De Jun Yan ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Tensile Stress ◽  
Welded Joints ◽  
Welding Residual Stress ◽  
Yield Limit ◽  
Stud Welding ◽  
Welding Joints ◽  
Simulation Results ◽  
Steel Stud

The distribution and value of welding residual stress for 1Cr18Ni9 stainless steel stud welding joints was systemically simulated by ANSYS FE software. The mathematical estimating models of strength of the welded joints were established. Simulation results showed that the welding residual stress was tensile at the edge of the stud, while it was compressive stress at the position near axis center. The largest tensile stress did not exceed yield limit of material. The residual stress had more influence on the strength of welded joints.

Finite Element Analysis of Residual Stresses in Butt Welding of Stainless Steel Plates by GTAW

2010 ◽  
Author(s):  
Gurinder Singh Brar ◽  
Rakesh Kumar
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
304 Stainless Steel ◽  
Aisi 304 Stainless Steel ◽  
Element Analysis ◽  
Aisi 304 ◽  
Butt Welding

Welding is one of the most commonly used permanent joining processes in the piping and pressure vessel industry. During welding a very complex thermal cycle is applied to the weldment, which in turn causes irreversible elastic-plastic deformation and consequently gives rise to the residual stresses in and around fusion zone and heat affected zone (HAZ). Presence of residual stresses may be beneficial or harmful for the structural components depending on the nature and magnitude of stresses. The beneficial effect of compressive stresses have been widely used in industry as these are believed to increase fatigue strength of the component and reduce stress corrosion cracking and brittle fracture. In large steel fabrication industries such as shipbuilding, marine structures, aero-space industry, high speed train guide ways and pressure vessels and piping in chemical and petrochemical industry the problem of residual stresses and overall distortion has been and continue to be a major issue. It is well established fact that material response of structural components is substantially affected by the residual stresses when subjected to thermal and structural loads. Due to these residual stresses produced in and around the weld zone the strength and life of the component is reduced. As AISI 304 stainless steel has excellent properties like better corrosion resistance, high ductility, excellent drawing, forming and spinning properties, so it is almost used in all types of application like chemical equipment, flatware utensils, coal hopper, kitchen sinks, marine equipment etc. But because of the problems of residual stresses during the time of welding it is very essential to understand the behavior and nature of AISI 304 stainless steel material. So in order to overcome all these problems a 3-dimensional finite element model is developed in a commercially available FEA code by drafting an approximate geometry of the butt welded joint and then the finite element analysis is performed, so that one can understand the complete nature of residual stresses in butt welding of AISI 304 stainless steel plate. In this paper, butt welding simulations were performed on two AISI 304 stainless steel plates by gas tungsten arc welding (GTAW). Analysis of butt welded joint by commercially available finite element analysis code showed that butt weld produced by GTAW resulted in 782.84 MPa of residual stress in plates. In addition, the residual stress is plotted against axial distance to have a clear picture of the magnitude of residual stress in and around weld area.

Residual stress and simulation of 304–430 stainless steel dissimilar laser-welded joints incorporating materials heterogeneity

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xilong Zhao ◽  
Feng He ◽  
Kun Wang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Laser Welding ◽  
Finite Element Model ◽  
Welded Joints ◽  
Steel Plate ◽  
Element Model ◽  
Stainless Steel Plate ◽  
Welding Temperature

Abstract An Nd:YAG laser device is used to conduct laser welding for a 1 mm austenitic stainless steel plate and a ferritic stainless steel plate. A finite element model of the shear punching test is constructed to generate the maximum shear strength in the weld, and the finite element model of laser welding is created using the welding temperature field. The hole drilling test result and the residual stress generated by two algorithms (Nonuniform-material and uniform-material) are compared. Results show that a drop-off of residual stress in the central area of the welded joint is observed when materials heterogeneity is disregarded. When materials heterogeneity is considered, the residual stress curve indicates smooth transition. The value of the latter appears reasonably similar to the experimental value. Therefore, this solution is advantageous in terms of residual stress simulation in dissimilar welded joints and does not critically affect residual deformation.

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