Effect of Bead Deposition by Repair Welding on Residual Stress in Pipe Welds

2004 ◽  
Author(s):  
Masahito Mochizuki ◽  
Masao Toyoda
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Weld Metal ◽  
Initial Stress ◽  
Heat Input ◽  
Welded Joint ◽  
Repair Process ◽  
Residual Stress Distribution ◽  
Initial Residual Stress ◽  
Plastic Analysis

Residual stress by repair welds in a pipe weld is computed using the thermal elastic-plastic analysis. Weld bond and heat-affected zone of a butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered for reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress.

Influence of the Welded Joint on the Mechanical Behavior of Steel Piles during Static and Dynamic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 1469-1472
Author(s):  
Gab Chul Jang ◽  
Kyong Ho Chang ◽  
Chin Hyung Lee
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Mechanical Behavior ◽  
Welded Joint ◽  
Dynamic Deformation ◽  
Three Dimensional ◽  
Steel Structures ◽  
Residual Stress Distribution ◽  
Dynamic Mechanical Behavior ◽  
Steel Piles

During manufacturing the welded joint of steel structures, residual stress is produced and weld metal is used inevitably. And residual stress and weld metal influence on the static and dynamic mechanical behavior of steel structures. Therefore, to predict the mechanical behavior of steel pile with a welded joint during static and dynamic deformation, the research on the influence of the welded joints on the static and dynamic behavior of steel pile is clarified. In this paper, the residual stress distribution in a welded joint of steel piles was investigated by using three-dimensional welding analysis. The static and dynamic mechanical behavior of steel piles with a welded joint is investigated by three-dimensional elastic-plastic finite element analysis using a proposed dynamic hysteresis model. Numerical analyses of the steel pile with a welded joint were compared to that without a welded joint with respect to load carrying capacity and residual stress distribution. The influence of the welded joint on the mechanical behavior of steel piles during static and dynamic deformation was clarified by comparing analytical results

Analysis of Residual Stress Distribution Characteristics at Nozzle Weld in Pressure Vessel and Pipe Components

2019 ◽  
Author(s):  
Shaopin Song ◽  
Pingsha Dong
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Wall Thickness ◽  
Heat Input ◽  
Critical Role ◽  
Residual Stress Distribution ◽  
Thickness Ratio ◽  
Stress Profile ◽  
Distribution Characteristics ◽  
Force Calculation

Abstract In order to achieve a better understanding of residual stress distribution characteristics associated with nozzle welds, this paper focuses on the identification of key parameters that contribute to the development of through-thickness membrane and bending components. This is because, as demonstrated in recent publications by the same authors (Song and Dong, 2016–2017), statically equivalent membrane and bending content in a given residual stress distribution play a far more critical role in fracture driving force calculation in Fitness-for-Service (FFS) assessment. To do so, a recent detailed investigation to residual stress distributions in nozzle welds is presented in this paper, covering nozzle radius to wall thickness ratio from 2 to 50, heat input from 400 J/mm to 1000 J/mm, weld joint types including set-in nozzle weld and set-on nozzle weld. By means of a residual stress decomposition technique, controlling parameters that govern through-thickness membrane and bending stresses have been identified, which are nozzle radius to wall thickness ratio (r/t) and linear heat input parameter (Q). Then, a unified functional form for representing through-thickness residual stress profile in nozzle weld is presented for supporting fitness for service assessment, e.g., by means of API 579-RP.

scholarly journals Evaluation of Residual Stress Distribution in Austenitic Stainless Steel Pipe Butt-Welded Joint

2009 ◽  
Vol 27 (2) ◽  
pp. 240s-244s ◽  
Author(s):  
Akira MAEKAWA ◽  
Michiyasu NODA ◽  
Shigeru TAKAHASHI ◽  
Toru OUMAYA ◽  
Hisashi SERIZAWA ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Stress Distribution ◽  
Welded Joint ◽  
Residual Stress Distribution ◽  
Steel Pipe ◽  
Stainless Steel Pipe

Evaluation of Rolling Contact Fatigue of a Carburized Wind Turbine Gear Considering the Residual Stress and Hardness Gradient

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Wei Wang ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Philippe Bocher ◽  
Heli Liu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Residual Stress Distribution ◽  
Rolling Contact ◽  
Material Strength ◽  
Initial Residual Stress ◽  
Failure Risk ◽  
Local Material

Carburized gears are applied extensively in large-scale heavy duty machines such as wind turbines. The carburizing and quenching processes not only introduce variations of hardness from the case to the core but also generate a residual stress distribution, both of which affect the rolling contact fatigue (RCF) during repeated gear meshing. The influence of residual stress distribution on the RCF risk of a carburized wind turbine gear is investigated in the present work. The concept of RCF failure risk is defined by combining the local material strength and the multi-axial stress condition resulting from the contact. The Dang Van multi-axial fatigue criterion is applied. The applied stress field is calculated through an elastic-plastic contact finite element model. Residual stress distribution and the hardness profile are measured and compared with existed empirical formula. Based upon the Pavlina–Tyne relationship between the hardness and the yield strength, the gradient of the local material strength is considered in the calculation of the RCF failure risk. Effects of the initial residual stress peak value and its corresponding depth position are studied. Numerical results reveal that compressive residual stress (CRS) is beneficial to RCF fatigue life while tensile residual stress (TRS) increases the RCF failure risk. Under heavy load conditions where plasticity occurs, the accumulation of the plastic strain within the substrate is significantly affected by the initial residual stress distribution.

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