Influence of Welding Parameters on Residual Stress in 9% Ni Steel for Low Temperature Service

2010 ◽  
Vol 154-155 ◽  
pp. 1618-1623 ◽  
Author(s):  
Chun Yan Yan ◽  
Wu Shen Li ◽  
Shi Wu Bai
Keyword(s):  
Residual Stress ◽  
Temperature Field ◽  
Welded Joint ◽  
Welding Residual Stress ◽  
Welding Parameters ◽  
Transformation Theory ◽  
Element Analysis ◽  
Heat Transfer Theory ◽  
Longitudinal Residual Stress ◽  
Simulation Results

Based on welding heat transfer theory, heat elastoplasticity theory and phase transformation theory, welding residual stress in multi-layer welded joint of 9% Ni steel for liquefied natural gas (LNG) storage tanks was simulated using SYSWELD finite element analysis software. Taking into account nonlinear relationships between temperature and mechanical properties, together with influence of transformation latent heat on temperature field, double ellipsoid heat source model was applied in the simulation of the three fields (temperature field, microstructure field and stress-strain field). Distribution pattern of welding residual stress in 9%Ni steel welded joint was obtained through numerical simulation. Results showed that heat affected zone (HAZ) showing high-level residual stress was the main stress concentrated part of the welded joint. Longitudinal residual stress appeared to be tensile in the weld and HAZ, and compressive in regions remote from the weld. A match of low heat input and high interpass temperature should be employed to lower residual stress level in HAZ. Simulation results were well consistent with theoretical analysis.

Welding Residual Stress Numerical Simulation of Guyed Mast Earplate Welded Joint

2014 ◽  
Vol 501-504 ◽  
pp. 740-743
Author(s):  
Yi Fei Wang ◽  
Wei Lian Qu ◽  
Wen Li Wang ◽  
Liang Wang ◽  
Bai Feng Ji
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Temperature Field ◽  
Heat Source ◽  
Welded Joint ◽  
Welding Residual Stress ◽  
Welding Temperature ◽  
Simulation Results ◽  
Guyed Mast

Fatigue damage of guyed mast earplate welded joint is one of the main failure forms of guyed mast under wind load, and the welding residual stress is a important influence on fatigue performance of the welded joints, therefore, accurate welding residual stresses assessment of earplate welded joint is of great significance to the research on fatigue performance of guyed mast earplate welded joint under wind load. In this paper, welding temperature field of earplate welded joint was simulated by using thermal finite element method and the gauss heat source was used as thermal input. Then, welding residual stress of earplate welded joint was simulated by using thermal elastic-plastic finite element method and the temperature field results were used as the load. The welding temperature field simulation results better reflect the locality of heating, mobility of heat source and instantaneity of heating and cooling process during the welding process. The welding residual stress simulation results show that the residual stress peak of earplate welded joint reaches the yield strength of material, and appears at the dangerous point of earplate welded joint under structural external load. This point under influence of the welding residual stress and structure load is likely to be fatigue crack initiation location.

Influence of Laser Shock Processing on the Weld Line and Finite Element Simulation

2011 ◽  
Vol 464 ◽  
pp. 627-631
Author(s):  
Jie Zhang ◽  
Ai Hua Sun ◽  
Le Zhu ◽  
Xiang Gu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Welding Residual Stress ◽  
Laser Shock ◽  
Analysis Software ◽  
Laser Shock Processing ◽  
Element Analysis ◽  
Welding Line ◽  
Simulation Results ◽  
Shock Processing

Welding residual stress is one of the main factors that affect the strength and life of components. In order to explore the effect on residual stress of welding line by laser shock processing, finite element analysis software ANSYS is used to simulate the welding process, to calculate the distribution of welding residual stress field. On this basis, then AYSYS/LS-DYNA is used to simulate the laser shock processing on welding line. Simulation results show that residual stress distributions of weld region, heat-affected region and matrix by laser shock processing are clearly improved, and the tensile stress of weld region effectively reduce or eliminate. The simulation results and experimental results are generally consistent, it offer reasons for parameter optimization of welding and laser shock processing by finite element analysis software.

Crack Extension Effects on Welding Residual Stress in Fitness for Service Assessment of Crack-Like Defect in Weld

2016 ◽  
Author(s):  
Jeong K. Hong
Keyword(s):  
Residual Stress ◽  
3D Models ◽  
Crack Size ◽  
Welding Residual Stress ◽  
Welding Parameters ◽  
Element Analysis ◽  
Defect Assessment ◽  
Technical Issues ◽  
Model Geometry ◽  
2D And 3D

The current industry code and standard fitness-for-service assessment (ICS FFSA) procedures ignore the release of the welding residual stress (WRS) in defect assessment of a crack growing in a WRS field. Doing so can result in overly restrictive results in the ICS FFSA of an engineering component. The current ICS FFSA procedures have produced compendiums of WRS distributions and stress intensity factor (SIF) solutions that are characterized by the joint geometry and welding parameters. It is also known that these distributions are based on extensive numerical analyses and provide upper bound estimates; therefore, these types of solutions do not necessarily satisfy the self-equilibrating state. In this investigation, through-wall WRS distributions from the literature data, including measurements and finite element analysis (FEA) results for girth welded pipes, are compared to the representative ICS FFSA WRS procedures. Also, the WRS and SIF solutions using the proposed procedure are compared to those using the ICS FFSA procedures employing 2D and 3D models. From the investigation, it is observed that the ICS FFSA procedures show discrepancies for certain conditions and the levels of conservatism are dependent on the model geometry, boundary constraint condition, crack size, and crack shape. For some cases, the estimations provided from the ICS FFSA procedures are not conservative compared to the reference solutions from literatures and FEA simulations. As a continuous study of the previous investigation [OMAE 2015-41319], the objective of the present paper is to motivate the industry to improve ICS FFSA procedures by clarifying the ambiguous technical issues of crack-like defect assessment in weld regions.

Numerical Simulation of Welding Residual Stress and its Creep Strain for Cr5Mo Steel Welded Joint

2011 ◽  
Vol 55-57 ◽  
pp. 41-46
Author(s):  
Ling Cheng ◽  
Zheng Nan Chen ◽  
Jian Gao
Keyword(s):  
Residual Stress ◽  
High Temperature ◽  
Welded Joint ◽  
Great Influence ◽  
Welding Residual Stress ◽  
Element Analysis ◽  
Creep Analysis ◽  
The Finite Element Analysis ◽  
Sequential Coupling ◽  
High Temperature Components

By the finite element analysis codes ABAQUS and the function of RESTART, a sequential coupling calculating program for creep based on welding residual stress has been developed by establishing the model of temperature field, residual field and creep analysis. The welding residual stress and creep of welded joint for Cr5Mo furnace tubes was simulated by the program. This method established the basis for calculating the effects of welding residual stress on the creep of welded joint. A creep comparison between the welded joint tubes with welding residual stress and with internal pressure was made in the paper. The results show that although the residual stress is greatly decreased due to the creep relaxation behavior at high temperature, the initial welding residual stress has a great influence on the tube creep. The research results provide a reference for strength design of high temperature components.

Finite Element and Experimental Analysis of Residual Stresses in Electron Beam Welded Nickel-Based Superalloys

2021 ◽  
Author(s):  
Tom Saju ◽  
M. Velu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Electron Beam ◽  
Residual Stresses ◽  
Electron Beam Welding ◽  
Stress Measurement ◽  
Welding Parameters ◽  
Element Analysis ◽  
Longitudinal Residual Stress ◽  
Nimonic 80A

In this paper, two different nickel-based superalloys, namely Inconel 718 and Nimonic 80A were joined using electron beam welding techniques with three different welding parameters. A finite element analysis (FEA) using Abaqus software was carried out to calculate the residual stresses due to welding. Both transverse and longitudinal residual stresses were determined. Also, an X-ray residual stress measurement system, μ-X360 Ver. 2.5.6.2 was used for measuring transverse residual stress along and across the weld centerline. The transverse residual stress found by FEA and that measured experimentally was nearly the same thus validating the FEA. Also, the peak values of longitudinal residual stress found using the FEA were close to the yield strengths of the base metals as found elsewhere.

Effect of Welding Residual Stress on the Buckling Behavior of Storage Tanks Subjected to Harmonic Settlement

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Jian-Guo Gong ◽  
Lei Yu ◽  
Feng Wang ◽  
Fu-Zhen Xuan
Keyword(s):  
Residual Stress ◽  
Design Method ◽  
Welding Residual Stress ◽  
Welding Parameters ◽  
Strengthening Effect ◽  
Storage Tanks ◽  
Buckling Strength ◽  
Welding Joint ◽  
Buckling Behavior ◽  
Significant Difference

The effect of welding residual stress on the buckling behavior of storage tanks subjected to the harmonic settlement was simulated using the shell-to-solid coupling method. In the numerical model of tanks coupled with the welding residual stress, the welding joint and its adjacent zone were modeled using the solid submodel and the zone far away from the welding joint was built by the shell submodel. Effects of welding parameters (e.g., welding velocities and welding passes) on the buckling behavior of tanks were analyzed systematically. Results indicate that the buckling strength of tanks is enhanced due to the welding residual stress. Comparatively, a slow welding velocity presents a more remarkable strengthening effect than the fast welding velocity due to a larger axial residual stress produced at the welding joint. Nevertheless, no significant difference between the double-side welding and the one-side welding for buckling strength enhancement is observed for the cases studied. This indicates that the current design method causes a conservative design without considering the welding residual stress.

Research on the Effects of Welding Sequence on Welding Residual Stress of High-Speed Train Based on SYSWELD

2011 ◽  
Vol 399-401 ◽  
pp. 1806-1811
Author(s):  
Yong Hong Chen ◽  
Peng Chen ◽  
Ai Qin Tian
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
High Speed ◽  
Element Model ◽  
Welding Residual Stress ◽  
High Speed Train ◽  
Distribution Law ◽  
Element Analysis ◽  
Welding Sequence ◽  
Maximum Residual Stress

The finite element model of the roof of aluminum high-speed train was established, double ellipsoid heat source was employed, and heat elastic-plastic theory was used to simulate welding residual stress of the component under different welding sequence based on the finite element analysis software SYSWELD. The distribution law of welding residual stress was obtained. And the effects of the welding sequence on the value and distribution of residual stress was analyzed. The numerical results showed that the simulation data agree well with experimental test data. The maximum residual stress appears in the weld seam and nearby. The residual stress value decreases far away from the welding center. Welding sequence has a significant impact on the final welding residual stress when welding the roof of aluminum body. The side whose residual stress needs to be controlled should be welded first.

scholarly journals Study on Residual Stress of Welded Hoop Structure

2020 ◽  
Vol 10 (8) ◽  
pp. 2838
Author(s):  
Wenbo Ma ◽  
Heng Zhang ◽  
Wei Zhu ◽  
Fu Xu ◽  
Caiqian Yang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Welding Speed ◽  
Weld Seam ◽  
Outer Cylinder ◽  
Three Dimensional ◽  
Welding Residual Stress ◽  
Welding Parameters ◽  
Forming Process ◽  
Maximum Residual Stress

Residual stress is inevitable during welding, which will greatly affect the reliability of the structure. The purpose of this paper was to study the residual stress of the hoop structure caused by the cooling shrinkage of the weld when the outer cylinder was wrapped and welded under the condition of the existing inner cylinder. In this paper, the “method of killing activating elements” of ANSYS was used to simulate the three-dimensional finite element of the hoop structure. In the case of applying interlayer friction, the welding-forming process and welding circumferential residual stress of the hoop structure were analyzed. The blind hole method was used to test the residual stress distribution of the hoop structure, and the test results were compared with the finite element simulation results to verify the reliability of the simulation calculation method and the reliability of the calculation results. Then, the influence factors of the maximum welding residual stress of the hoop structure were studied. The results show that the maximum residual stress of the outer plate surface of the hoop structure decreases with the increase of the welding energy, the thickness of the laminate, the width of the weld seam, the welding speed, and the radius of the container. Based on the results of numerical simulation, the ternary first-order equations of the maximum residual stress of the hoop structure with respect to the welding speed, the thickness of the laminate, and the width of the weld seam were established. Then, the optimal welding parameters were obtained by optimizing the equations, which provided an important basis for the safe use and optimal design of the welding hoop structure.

An Efficient Modelling Approach for Predicting Residual Stress in Power-Beam Welds

2019 ◽  
Author(s):  
Graeme Horne ◽  
Danny Thomas ◽  
Andrew Collett ◽  
Andrew Clay ◽  
Martin Cott ◽  
...  
Keyword(s):  
Residual Stress ◽  
Structural Integrity ◽  
Welding Residual Stress ◽  
Contour Method ◽  
Element Analysis ◽  
Stress Measurements ◽  
316L Austenitic Stainless Steel ◽  
Important Input ◽  
Integrity Assessments ◽  
Modelling Approach

Abstract The prediction of welding residual stress in components is often an important input to structural integrity assessments. An efficient modelling approach was developed for predicting residual stress in power-beam welds, including validation against residual stress measurements. Specifically, sequentially coupled thermo-mechanical finite element analysis was conducted using a simplified heat source that was tuned to the observed fusion zone from a weld macrograph and thermocouple data for a series of electron beam welds in 316L austenitic stainless steel with a variety of geometries. The predicted residual stresses were compared with contour method and neutron diffraction residual stress measurements.

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