Residual Stresses Redistribution in Girth Weld Pipe After Reduction of the Wall Thickness

2017 ◽  
Author(s):  
Xavier Ficquet ◽  
Remi Romac ◽  
Karim Serasli ◽  
Ed J. Kingston
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Wall Thickness ◽  
Hole Drilling ◽  
Gas Oil ◽  
Internal Corrosion ◽  
The North ◽  
Before And After ◽  
The North Sea ◽  
Welded Pipe

Girth welded pipes, such as those located offshore on platforms in the North Sea, are subjected to highly corrosive environment. The need to consider welding residual stresses in the assessment of the fitness for service and damages to these pipes when investigating local corrosion damages across a welded region is therefore important for the operators of the platforms and the manufacturers of the pipes. This paper presents a review of work carried out to ascertain the welding residual stresses present within a thin-walled girth welded pipe mock-up made from steel API 5LX Grade 52 before and after reduction of the wall thickness. The mock-up was manufactured to replicate typical pipes used to convey gas, oil and water through the platforms. The mock-up was of diameter 30” and of thickness 19mm. The incremental deep hole drilling (iDHD), contour, hole drilling, XRD, and ultrasonic technique were applied to characterise the residual stresses in the weld and heat affected zone of the specimen. The residual stresses were then measured during the manufacture of a groove located on the weld at the ID and were compared to an FE prediction. Ultrasonic measurements were then carried out on the outer surface of the pipe and show a significant increase in the residual stress and could be used to monitor the changes in the residual stress caused by internal corrosion.

Residual Stresses in Steel-Titanium Composite Manufactured by Explosive Welding

2012 ◽  
Vol 726 ◽  
pp. 125-132 ◽  
Author(s):  
Aleksander Karolczuk ◽  
Krzysztof Kluger ◽  
Mateusz Kowalski ◽  
Fabian Żok ◽  
Grzegorz Robak
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Hole Drilling ◽  
Element Analysis ◽  
Welded Steel ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Before And After ◽  
Stress States

The main aim of the paper is determination of residual stresses in explosively welded steel-titanium bimetal. The analysis considers two bimetallic specimens: before and after the heat treatment. In residual stress determination the hole drilling method along with finite element analysis were applied. The results show different residual stress states depending on the heat treatment. The obtained results are confirmed by thermal stress calculation.

Reduce the Residual Stress of Welded Structures by Post-Weld Vibration

2005 ◽  
Vol 490-491 ◽  
pp. 102-106 ◽  
Author(s):  
De Lin Rao ◽  
Zheng Qiang Zhu ◽  
Li Gong Chen ◽  
Chunzhen Ni
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Mechanical Vibration ◽  
Welding Process ◽  
Hole Drilling ◽  
Welded Structures ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Before And After

The existence of residual stresses caused by the welding process is an important reason of cracking and distortion in welded metal structures that may affect the fatigue life and dimensional stability significantly. Heat treatment is one of the traditional methods to relieve the residual stresses. But it is often limited by the manufacturing condition and the size of the structures. In this paper a procedure called vibratory stress relief (VSR) is discussed. VSR is a process to reduce and re-distribute the internal residual stresses of welded structures by means of post-weld mechanical vibration. The effectiveness of VSR on the residual stresses of welded structures, including the drums of hoist machine and thick stainless steel plate are investigated. Parameters of VSR procedure are described in the paper. Residual stresses on weld bead are measured before and after VSR treatment by hole-drilling method and about 30%~50% reduction of residual stresses are observed. The results show that VSR process can reduce the residual stress both middle carbon steel (Q345) and stainless steel (304L) welded structures effectively.

Investigation of the Performance of the Contour Residual Stress Measurement Method When Applied to Welded Pipe Structures

2009 ◽  
Author(s):  
R. J. Dennis ◽  
N. A. Leggatt ◽  
E. A. Kutarski
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Measurement Method ◽  
Stress Measurement ◽  
Complex Structure ◽  
Cutting Process ◽  
Residual Stress Measurement ◽  
Contour Method ◽  
Hole Drilling ◽  
Welded Pipe

The ‘Contour Method’ is a relatively new relaxation method for residual stress measurement and may be seen as an evolution of established methods such as hole drilling. The general procedure when applying the Contour Method is cutting, measurement and calculation of residual stress normal to the cut plane using Bueckner’s principle of elastic superposition. That is the residual stresses are determined from the measured profile of a cut surface. While the Contour Method is simple in concept there are certain underlying issues relating to the cutting process that may lead to uncertainties in the measured results. Principally the issues are that of constraint and plasticity during the cutting process and the influence that they have on the measured residual stresses. Both of these aspects have been investigated in previous work by simulating the entire contour measurement method process using finite element techniques for ‘simple’ flat plate welded specimens. Here that work is further investigated and extended by application to a 316 Stainless Steel welded pipe structure containing a part-circumferential repair. This more complex structure and residual stress field is of significantly greater engineering interest. The key objective of this work is to ascertain the feasibility of and further our understanding of the performance of the Contour Method. Furthermore this work has the potential to provide a method to support the optimisation of the contour measurement process when applied to more complex engineering components.

A Comparison Between Measured and Modeled Residual Stresses in a Circumferentially Butt-Welded P91 Steel Pipe

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
A. H. Yaghi ◽  
T. H. Hyde ◽  
A. A. Becker ◽  
W. Sun ◽  
G. Hilson ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Wall Thickness ◽  
Element Model ◽  
Numerical Approach ◽  
Martensite Phase ◽  
Steel Pipe ◽  
Hole Drilling ◽  
Outer Diameter ◽  
Power Generation Plant ◽  
Welded Pipe

Residual macrostresses in a multipass circumferentially butt-welded P91 ferritic steel pipe have been determined numerically and experimentally. The welded joint in a pipe with an outer diameter of 290 mm and a wall thickness of 55 mm is typical of power generation plant components. An axisymmetric thermomechanical finite element model has been used to predict the resulting residual hoop and axial stresses in the welded pipe. The effects of the austenite to martensite phase transformation have been incorporated into the simulation. Residual stresses have been measured using the X-ray diffraction technique along the outer surface of the pipe and using the deep-hole drilling technique through the wall thickness at the center of the weld. Good correlation has been demonstrated between the residual hoop and the axial stresses obtained numerically and experimentally. The paper demonstrates the importance of using a mixed experimental and numerical approach to determine accurately the residual macrostress distribution in welded components.

Failure Mechanisms of Equal and Unequal Wall Thickness Hybrid Maraging Steel-P20 Tubular Joints: Effects of Welding Residual Stresses

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Alireza Ebrahimi ◽  
Shawn Kenny ◽  
Mohsen Mohammadi
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Residual Stresses ◽  
Maraging Steel ◽  
Wall Thickness ◽  
Mechanical Performance ◽  
Fe Modeling ◽  
Residual Stress State ◽  
Welded Pipe ◽  
Pipe Joint

Abstract Joining an additively manufactured component to a forged or cast part through welding processes has recently attracted the attention of engineers and scientists. This technique integrates the technical benefits of additive manufacturing (AM) technology with conventional processes that may be more cost-efficient. In this paper, the effect of residual stresses on the mechanical performance of a hybrid welded pipe joint connecting an additively manufactured maraging steel (MS1) pipe segment with a conventional P20 steel tube having an equivalent outside diameter was studied. A sequentially coupled thermo-mechanical continuum finite element (FE) modeling procedure to predict the residual stress state on circumferential pipe hybrid MS1-P20 joints subjected to multi-axial loads was developed and validated. Available experimental data on a welded pipe joint with conventional stainless steel (SUS304) were used to calibrate the model. The FE modeling procedures were further validated for the hybrid MS1-P20 joint. The predicted residual stress state was mapped on the pipe joint with equal and unequal wall thickness joint transitions. The mechanical performance of these pipe joints was evaluated with the application of internal pressure, uniaxial tension, and flexural loads. The major contribution of this study was the proposition of a new concept of hybrid joints, where a significant transition of the load was expected. The new hybrid joint concept was presented to meet the existing design criteria requirements without sacrificing other parameters (e.g., component weight and manufacturing expense) and facilitate the production of hybrid components using AM techniques.

Residual Stress Analyses of a Multi-Pass Girth Weld: 3-D Special Shell Versus Axisymmetric Models

2000 ◽  
Vol 123 (2) ◽  
pp. 207-213 ◽  
Author(s):  
P. Dong
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Wall Thickness ◽  
Stress Component ◽  
Thick Wall ◽  
Hole Drilling ◽  
Thin Wall ◽  
Weld Residual Stress ◽  
Stress Analyses

In this paper, detailed weld residual stress analyses are presented for a typical multi-pass girth weld in Type 316L stainless steel pipe with r/t ratio of 25. Advanced finite element procedures were used to simulate the residual stress development under controlled welding conditions associated with weld mock-ups. Both axisymmetric and 3-D special shell element models were used to reveal local residual stress details and global residual stress characteristics in the girth weld. Residual stress measurements using hole-drilling method were conducted for model validation on the laboratory weld mock-up welds. A good agreement between finite element predictions and experimental measurements were obtained. The major findings include: (a) Axial residual stresses within and near the weld area exhibit a strong bending feature across the pipe wall thickness, while the hoop residual stresses showed a much less variation through the wall thickness. (b) Some periodic variation of the residual stresses is present along the pipe circumference near the weld, particularly for the axial residual stress component. Such a variation tends to become more pronounced in thick wall than in thin wall girth welds. A 3-D model is essential to adequately capture such 3-D features in residual stress distributions. (c) A rapid variation in weld residual stresses can be seen at start/stop positions, where a high magnitude of axial residual stresses is present in both tension and compression.

Effect of Ageing on Residual Stresses in a Girth Welded Stainless Steel 316 L Pipe

2019 ◽  
Author(s):  
R. J. Coulthard ◽  
M. Mostafavi ◽  
C. E. Truman
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Service Use ◽  
Hole Drilling ◽  
Stainless Steel 316L ◽  
Weld Residual Stress ◽  
Before And After ◽  
Maximum Residual Stress ◽  
Stainless Steel 316

Abstract Residual stresses within welded components can redistribute when exposed to high temperatures and large levels of loading. The ageing process for a specimen attempts to replicate the temperature regime experienced during typical service use of the component, redistributing stresses from the as-welded condition to post-ageing. The aim of this investigation was to study the effects of ageing on weld residual stress redistribution and to evaluate the changes in the residual stress profiles before and after the pipe had been aged. In this investigation the through thickness residual stresses within a narrow gap girth TIG welded stainless steel 316L pipe were measured. The ageing of the pipe specimen involved heating to 400°C for 3000 hours. To measure residual stress the incremental Deep-Hole Drilling (iDHD) method was employed; two measurements were taken, once before and after ageing. Analysis of the measured pre and post-ageing residual stresses showed a consistent reduction in the magnitude of approximately 50 MPa, corresponding to the change in the yield stress of the material at room and elevated (400°C) temperatures; the maximum residual stress, of 450 MPa, was measured at 4 mm from the external surface of the pipe.

Effect of Ageing on Residual Stresses in Welded Stainless Steel Cylinders

2012 ◽  
Author(s):  
Son Do ◽  
David Smith ◽  
Mike Smith
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Power Stations ◽  
Before And After ◽  
Girth Welds ◽  
Effects Of Aging ◽  
Hoop Stresses

Operation of components at high temperature in power stations leads to the relaxation of residual stresses created in welded stainless steel cylinders. In this work a number of Esshete 1250 stainless steel cylinders containing girth welds and repair welds were manufactured. Two cylinders were then put to a furnace for 10,000hrs and 20,000hrs at 650°C. These conditions simulated the effects of aging. The residual stresses in the girth welds and repair welds before and after aging were measured using a number of methods based around the Deep Hole Drilling method. This paper describes the experiments carried out to obtain the through-wall distribution of stresses. It is evident that there was significant relaxation of the residual stresses due to aging. The peak tensile residual stress in girth welds was relaxed from 500MPa to 110MPa and the peak compressive residual stress in girth welds was relaxed from −301MPa to −135MPa after 10,000 hours at 650°C. The repair weld residual stresses were not only relaxed at the peak stresses but relaxed average levels from 220MPa to 140MPa for hoop stresses and from 180MPa to 145MPa for axial stresses. The implications of these findings are discussed in the context of future fracture tests.

Analysis on Residual Stresses of the Casing Part in Aeroengine Based on Hole-Drilling Method

2013 ◽  
Vol 770 ◽  
pp. 159-163
Author(s):  
Dian Ye Cao ◽  
Yin Fei Yang ◽  
Zhi Wu Liu ◽  
Jie Yu ◽  
Liang Li
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Annealing Treatment ◽  
Residual Stress Distribution ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Measurement Results ◽  
Drilling Method ◽  
Before And After

In order to study the residual stress distribution of the casing part in aeroengine, the hole-drilling method was used to measure the residual stress before and after the annealing treatment. The measurement results indicated that the annealing treatment significantly improved the residual stress distribution in the part, and the residual stresses were showed as compressive stress. Meanwhile, the measured residual stress distribution would provide the basis for controlling the machining distortion of the casing part in aeroengine.

Residual Stress Measurement, Finite Element Mapping and Flaw Simulation for a Girth Welded Pipe

2015 ◽  
Author(s):  
Xavier Ficquet ◽  
Karim Serasli ◽  
Ed J. Kingston
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Stress Measurement ◽  
Hole Drilling ◽  
Fe Model ◽  
Mapping Procedure ◽  
Near Surface ◽  
Welded Pipe

Optimising the structural integrity of an oil and gas pipeline is hugely important for its productivity and hence profitability. The structural integrity of a pipeline is influenced by factors such as: stress (i.e. applied and residual), material properties, environment, and the size and orientation of contained flaws. For example, whilst in operation, the integrity of a pipeline can be extended by reducing its applied stresses e.g. the flow and pressure of the oil and gas running within. Prior to operation however the integrity of the pipeline can easily be extended by reducing the residual stresses generated during installation or even “negatively pre-loading” the pipeline using residual stresses to help cancel out some of the applied stresses. Therefore understanding the distribution of residual stresses within a pipeline can be of great benefit to Oil and Gas engineers. In this paper, complementary residual stress measurement techniques are used to obtain near surface and through-thickness residual stress distributions in a fully circumferential butt welded pipe. The deep hole drilling (DHD) method was used to obtain the axial and hoop residual stresses along radial lines through the pipe wall. Near surface measurements on the outer surface of the pipe were obtained using the incremental centre-hole drilling (ICHD) method. The measurements were made only at limited points in and adjacent to the circumferential weld. In order to estimate the complete residual stress field present in the pipe, a mapping procedure utilising a finite element (FE) method was implemented. This entailed introducing the measured residual stresses into a FE model of the pipe as an initial condition and allowing redistribution. Naturally, the stresses at the measurement locations should remain at their initial values. Consequently, the method was developed to allow redistribution while retaining the measured values. The paper provides these estimates of the full residual stress state present in the pipe based on this mapping procedure. The FE model was then used to simulate the influence of various sizes of flaw on the mapped residual stresses field. An assessment of the acceptability of areas of loss of the wall thickness in internally pressurised pressure vessels was then performed.

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