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Welded lined cylindrical structures such as boilers, pressure vessels and transportation pipes are widely used in the oil and gas industries because an inexpensive outer layer is protected from corrosion by a thinner expensive layer, which is made of a corrosion resistant alloy (CRA). Welding in the lined pipe is of two different types, where the f...
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... this study, the specimen of welded lined pipe schematically shown in Fig. 1 was manufactured from two adjacent pipes. The outer pipe is made of low carbon steel equivalent to E235 AISI 10305-1, known as C-Mn pipe, with an outer diameter of 114.3 mm and a wall thickness of 6.35 mm. The inner pipe is made of austenitic stainless steel which is rich in Cr and Ni, known as AISI304 pipe, with an outer diameter of ...
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... case A, the axial and hoop residual stress distributions at 270° central angle are depicted in Fig. 10(a) and (b), respectively. The bottom row of elements is the liner, AISI304 pipe, with the weld overlay, whereas the rest of pipe is the backing steel pipe, namely C-Mn pipe, with the girth ...
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... can be seen that maximum axial residual tensile stresses are located at the toes of the girth welding, weld overlay and HAZ on the inner surface as shown in Fig. 10(a). Furthermore, the axial tensile stresses on the inner surface are balanced by the axial compressive stresses on the FZ and HAZ of girth welding on the outer surface [18]. Therefore, axial bending deformation is produced through the pipe cross section. As a result, the diameter of lined pipe becomes smaller in the FZ and HAZ regions ...
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... to the hoop residual stress distributions shown in Fig. 10(b), the absolute values of tensile stresses in the FZ and HAZ on the inner surface are significantly larger than those of the compressive stresses in the girth welding region and its vicinity on the outer surface. The magnitudes of residual axial stresses have a significant influence on the value of residual hoop stresses [20]. The ranges ...
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... than carbon steel because of its chemical composition. As a result, austenitic stainless steel welding is preferred in the oil and gas industries. girth welding (Z ≤ 3.6 mm). Within this zone, the maximum axial residual stress is 593 MPa at Z = 0.3 mm in case A whilst the maximum one in case B is 529 MPa located at Z = 0.6 mm as shown in Fig. 12(a). Similarly, in the circumferential direction, the maximum hoop residual stress is 573 MPa, over the yield stress of AISI304 welding material, at Z = 2.1 mm in case A whereas the maximum one in case B is 481 MPa on the WCL as indicated in Fig. 12(b). On the outer surface, it can be seen that significant discrepancies exist between the ...
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... Z = 0.3 mm in case A whilst the maximum one in case B is 529 MPa located at Z = 0.6 mm as shown in Fig. 12(a). Similarly, in the circumferential direction, the maximum hoop residual stress is 573 MPa, over the yield stress of AISI304 welding material, at Z = 2.1 mm in case A whereas the maximum one in case B is 481 MPa on the WCL as indicated in Fig. 12(b). On the outer surface, it can be seen that significant discrepancies exist between the numerical results of case A and B in the FZ and its vicinity, for Z ≤ 45 mm, as shown in Fig. 12(c) and (d). Beyond this zone, the results in both cases are almost identical in the axial and hoop residual stress ...
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... welding by forming voids and inclusions. Therefore, in case C welding is conducted without weld overlay to study the influence of this factor on the stress behaviour. Case A-FEA Case B-FEA Case A-Exp. respectively. Beyond these weld zones, the axial residual stress distributions in both cases A and C are much closer to each other as shown in Fig. 13(a). Similarly, in the hoop direction, there is a difference in the hoop residual stress at the weld zones. Beyond that, the results are closer to each other in both cases as depicted in Fig. ...
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... Case A-Exp. respectively. Beyond these weld zones, the axial residual stress distributions in both cases A and C are much closer to each other as shown in Fig. 13(a). Similarly, in the hoop direction, there is a difference in the hoop residual stress at the weld zones. Beyond that, the results are closer to each other in both cases as depicted in Fig. ...
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... the outer surface, there are significant discrepancies between the results of axial and hoop residual stress in case A with their counterparts in case C at the weld zone of girth welding and its HAZ as shown in Fig. 13(c)-(d). The experimental results are in good agreement with the numerical results for both cases at the FZ and HAZ but they are larger beyond that especially at the inner surface due to the effect of initial residual stresses of pre-heat treatment (TFP). ...
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... removing the liner will not only lead to corrosion of the pipe in oil and gas applications but it will also affect the residual stress behaviour especially at welding regions [23]. MPa, is lower than that in case A, 540 MPa, as depicted in Fig. 15(a). In the hoop direction, the magnitude of hoop residual stress at the WCL in case F, 364 MPa, is larger than its counterpart in case A, 203 MPa. With increasing distance from the WCL, the hoop residual stress distribution drops rapidly in case F whereas the distribution in case A goes sharply up within the weld overlay region as shown ...
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... 15(a). In the hoop direction, the magnitude of hoop residual stress at the WCL in case F, 364 MPa, is larger than its counterpart in case A, 203 MPa. With increasing distance from the WCL, the hoop residual stress distribution drops rapidly in case F whereas the distribution in case A goes sharply up within the weld overlay region as shown in Fig. 15(b). Furthermore, the extent of the axial and hoop tensile stresses in case F is relatively narrower, Z = 19 mm, than that of case A, Z = 65 mm, on the inner surface as shown in Fig. 15(a) and (b). This can be attributed to the absence of the liner and of the weld overlay at the inner surface which in turn slows down the heat transfer of ...
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... WCL, the hoop residual stress distribution drops rapidly in case F whereas the distribution in case A goes sharply up within the weld overlay region as shown in Fig. 15(b). Furthermore, the extent of the axial and hoop tensile stresses in case F is relatively narrower, Z = 19 mm, than that of case A, Z = 65 mm, on the inner surface as shown in Fig. 15(a) and (b). This can be attributed to the absence of the liner and of the weld overlay at the inner surface which in turn slows down the heat transfer of the exposed surface to the environment. Axial distance ...
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... the outer surface, the maximum compressive axial stress in case F, -562 MPa, is located within the FZ, at Z = 2.1 mm, whilst the maximum compressive axial stress in case A is located at the WCL, -595 MPa, as shown in Fig. 15(c). In both cases, the hoop residual stress distributions have a wave form as shown in Fig. 15(d). As with tensile stresses at the inner boundary, the compressive range in case F is relatively narrower than that for case A. In general, the numerical residual stress results agree reasonably well with the experimental results obtained by ...
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... the outer surface, the maximum compressive axial stress in case F, -562 MPa, is located within the FZ, at Z = 2.1 mm, whilst the maximum compressive axial stress in case A is located at the WCL, -595 MPa, as shown in Fig. 15(c). In both cases, the hoop residual stress distributions have a wave form as shown in Fig. 15(d). As with tensile stresses at the inner boundary, the compressive range in case F is relatively narrower than that for case A. In general, the numerical residual stress results agree reasonably well with the experimental results obtained by using the hole-drilling strain gauge method. ...
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... to simulate depositing the filler materials in the weld overlay and girth welding while moving the heat source. The coarse mesh size is equal to or larger than 1.5 times the normal mesh size utilized in this study for case A (see Fig. 5) with the coarse mesh model being composed of 40 circumferential elements instead of 60 elements, as shown in Fig. 16. 0 20 40 60 80 100 120 140 160 180 ...
Citations
... Since some physical and thermal properties of Ferro55 are not available, the coating material's properties are decided based on those of AISI H13 comparable to Ferro55 (Komodromos et al., 2024). The physical and thermal properties used in the simulation are shown in Table 4 and Table 5 based on the literature (Lin et al., 2007;Mohajerani et al., 2017;Japan Society of Thermophysical Properties, 2008;MatWeb, LLC, 2024;Obeid et al., 2017;Fukuyama et al., 2022;Santhanakrishnan et al., 2011;Deng and Murakawa, 2006;Cezairliyan and Miiller, 1980). The specific heat and thermal conductivity are temperature-dependent, and others are temperature-independent. ...
High-speed directed energy deposition (DED) offers advantages such as efficiency, thin coating layers, and reduced heat-affected zones, making it ideal for repairs and coating on existing parts across various industries. In the DED process, various deposition parameters are included and affect the thermal history. Moreover, a thermal history significantly affects the deposit's mechanical properties by varying metallographic structure. Therefore, thermal simulations of DED are highly demanded due to the time and cost challenges associated with experimenting across different process parameters. However, thermal simulations of DED have difficulties because of the process by which material and heat source are supplied from time to time to the melt pool. Many studies have been conducted on thermal simulations of DED, however, few studies focus on high-speed DED coating. Therefore, this research develops the thermal simulation techniques for high-speed DED coating by exploring five simple methods for element addition and heat input. The geometry of the workpiece model was simplified to reduce the simulation cost. Using the Ansys Parametric Design Language (APDL) software and the simplified workpiece model, we conducted thermal simulations and validated them against experimental data acquired from high-speed imaging and two-color temperature measurements. Through these methods, the study proposed the temperature comparison method of experiment and simulation results and identified the suitable method for element addition and heat input in high-speed DED coating that closely replicates the actual temperature within the coating layer. This method reduces the need for finer mesh, effectively lowering computational costs while maintaining accuracy. The findings provide insights into practical simulation practices for DED and contribute to enhancing parameter validation in additive manufacturing simulations, supporting further development in high-speed DED coating technology.
... The whole length of the test 107 segment is 400 mm which is symmetric about the mid plane, welding centreline WCL. 109 Table 1 AISI 10305 and AISI 304 chemical composition [21]. The TFP pre-heating process, which mainly depends on expanding the outer pipe by heating 110 and shrinking the inner one by cooling down, is performed to insert the austenitic stainless 111 steel pipe inside the low carbon steel pipe. ...
... In this case, the total heat transfer coefficient takes into account the effect of 213 radiation and convection presented as Eq. (1) [21]: ...
... 320 rapidly and shrinks faster during natural cooling due to its thermal conductivity [21]. Based on Fig. 19 Fig. 28. ...
An experimental and numerical investigation on the thermal and mechanical response of a lined pipe (compound pipe) under welding is presented. The welding process consists of a single-pass overlay welding (inner lap-weld) and a two-pass girth welding (outer butt-weld). The influence of the filler material of the girth welding has been examined thermally and mechanically as it is a key factor that can affect the quality of lined pipe welding. To this end, a three-dimensional non-linear finite element model based on the ABAQUS code has been developed and successfully validated against small-scale experimental results. This study was conducted on two specimens of lined pipe joined together by a girth welding deposited either by mild steel or by austenitic stainless steel. Furthermore, in this study, a pre-heat treatment required to produce lined pipe specimens has been taken into account. Strains and residual stresses have been measured by means of high temperature strain gauges, residual stress gauges and the X-ray diffraction technique along the inner and outer surfaces of the welded lined pipe whereas the thermal history has been recorded by thermocouples. The findings point out that replacing the girth welding mild steel by austenitic stainless steel has a significant effect on the residual stress results but no influence on the thermal history results.
... Mechanical parameters are essential for the proper operation of the circumferentially welded tubular structures. A large amount of heat introduced into the joint has a significant impact on its strength properties [14][15][16][17] of welded pipes. Recognition of values of residual stresses is extremely important when analyzing the development of cracks in welded constructions [18,19]. ...
... Numerical prediction of the thermo-mechanical properties of welded joints and the selection of welding parameters can significantly accelerate the implementation and reduce the costs of the technological process. Over the past decade, a number of numerical models have been developed to evaluate the temperature distribution and residual stresses for welding of steel pipes [5][6][7][8][16][17][18]22]. Researchers use a full three-dimensional numerical model [8,18,[23][24][25] to analyze the effect of changing parameters during circumferential welding of pipes on the distribution of temporary and residual stresses, to analyze stress state resulting from joining dissimilar materials or to simulate the residual stresses during multi-pass welding of a pipe Many researchers choose axisymmetric 2D models to reduce computation time and costs in simulations of circumferential welding of pipes [4,5,26,27]. ...
... There is still a lack of verification of numerical models on the basis of experimentally determined field of values (such as displacement field) in the entire area of the analyzed sample. The current research in the field of numerical modelling of pipe welding is focused mainly on the analysis of thermomechanical phenomena in butt joints [8,[14][15][16][17]. There are only few papers available in the literature concerning numerical analysis of thermomechanical phenomena occurring in socket-welded pipes. ...
The paper presents a numerical model based on the finite element method (FEM) to predict deformations and residual stresses in socket welding of different diameter stainless steel pipes made of X5CrNi18-10 steel. The next part of the paper concerns the determination of strength properties of a welded joint in terms of a shear test. A thermo-elastic–plastic numerical model is developed using Abaqus FEA software in order to determine the thermal and mechanical phenomena of the welded joint. This approach requires the implementation of moveable heat source power intensity distribution based on circumferentially moving Goldak’s heat source model. This model is implemented in the additional DFLUX subroutine, written in Fortran programming language. The correctness of the assumed model of thermal phenomena is confirmed by examinations of the shape and size of the melted zone. The strength of the welded joint subjected to shear is verified by performing a compression test of welded pipes as well as computer simulations with validation of the computational model using the Dantec 3D image correlation system.
... [1][2][3][4] The circumferential butt weld is the most common type of the joints employed in the power plants for the fabrication of stainless steel piping systems. 5,6 In these piping systems, due to the rather large wall thickness, the welding process is completed normally in more than one pass of the weld. Due to the condensation of heat in the welding, the regions around and inside the weld zone experience thermal cycles causing uneven heating and cooling cycles in the metal. ...
... 8 In the risk assessment for defects growth, that is, cracks in piping systems, sometimes rather than the stress made by design loads, the residual stress made by the welding could be a crucial part of the total stress field. 5,9 Furthermore, to hinder inter-granular stress corrosion around the stainless steel weldments, it is essential to control the metal properties, the process situation, and the residual stresses caused probably by the welding. 10 As a result, a proper evaluation of the residual stress fields is important. ...
... The latent heat and liquidus and solidus temperatures for SUS304.5 ...
A numerical investigation is provided to study the residual stress states in multi-pass TIG welding of stainless steel SUS304 pipe. An uncoupled thermomechanical three-dimensional finite element model is developed using the ABAQUS software for a circular weld design around the pipe. The effects of weld pass numbers, electrode moving speed, and heat input on the internal and external surface tensions of the pipe are investigated. The simulation results show that by increasing the welding speed, the axial tensile stresses decrease on the pipe surfaces. In the case of hoop stress, as the welding speed raises, the tensile and compressive stresses are increased for both two- and three-pass welding. However, the width of the stress zone becomes narrower in higher welding speeds. The hoop stresses, in comparison with the axial stresses, are more strongly influenced by the welding speed and the heat input. Furthermore, using the three-pass welding process results in much lower stresses in comparison with the two-pass one.
... The welding processes have found widespread applications in the almost all branches of industry and construction [1,2]. The circumferential butt weld is the most common type of joint employed in the power plants for fabrication of stainless steel piping systems [3,4]. In these piping systems, due to the rather large wall thickness, the welding process completes normally in more than one pass of weld. ...
... The tensile residual stresses are mostly damaging, and improve the susceptibility of weldment to fracture, fatigue and corrosion cracking [6]. In the risk assessment for defects growth, i.e. cracks in piping systems, sometimes rather than the stress made by design loads, the residual stress made by welding could be the important part of total stress field [3,7]. Furthermore, to hinder inter-granular stress corrosion around the stainless steel weldments, it is essential to control the metal properties, process situation and residual stresses caused by welding [8]. ...
... Obeid et al. [3] proposed a 3D FE model based on the ABAQUS and studied the effects of different parameters including the weld overlay, girth welding materials, geometric parameters, and heat input on the thermal and residual stress fields. applications is simulated numerically by Xu and Wang [10], to estimate the residual stresses. ...
A numerical procedure is provided to analyze temperature and residual stress fields in multi-pass TIG welds with different pipe and electrode material. Based on the ABAQUS software and FORTRAN codes, to appraise the temperature fields and the residual stresses over the TIG process, an uncoupled thermo-mechanical, finite element model (FEM) is developed. For considering volumetric thermal flux on the workpiece, the “GOLDACK” method is used. The silent element method is utilized to model the weld deposit. To validate the presented simulation model, the TIG process is performed in two passes on SUS304 stainless steel pipe. Then, the process is modeled for three and four passes to consider the effect of pass number on axial and hoop residual stresses in the outer and inner surfaces of the welded pipes. Additionally, the effects of base material and preheating temperature on the internal and external surface stresses of pipe are investigated. Results show that, the base material type has a greater effect on the tensile axial residual stress of the outer surface rather than that of the inner surface. However, the welding pass number shows no significant influence on the peak of the tensile axial residual stress on the inner surface of the pipe. In terms of preheating, the stress magnitude is reduced by raising the preheating temperature but with more intense in the inner surface of the pipe. Additionally, to keep the tensile axial residual stress below the base metal yield strength, the preheating at least up to 325 °C is essential.
... The results showed that the maximum tensile residual stresses had happened in the interface of the weld and heat affected zone. Obeid et al. evaluated the parametric of thermal and residual stress and the effect of welding process in the lined pipe recently [10][11]. The investigation of in service behavior of the gas pipeline in the weld induced large residual stress zone requires comprehensive identification of the distribution of these stresses. ...
In order to achieve integrated condition in the girth welding of high pressure natural gas transmission pipelines, the weld zones and its surrounding area should have homogeneous mechanical properties as possible. Residual stresses are an important defect specially in the girth welding of pipeline. In this paper, two API X70 steel pipes (with spiral seam weld) of 56 inches outside diameter and 0.780 inch wall thickness were girth welded first. Hole drilling tests were conducted for residual stress measurement on the surfaces of the pipes. Hoop tensile residual stress on the external surface of the pipe with maximum value equal to 318-MPa was measured on the weld centerline. Hoop residual stress distributions in the internal and external surface of the pipe were approximately similar. The maximum axial residual stress was observed in the heat affected zone (a distance of approximately 30 mm from weld centerline). The maximum axial residual stress on the external surface of the pipe was tensile, equal to 137 MPa and on the internal surface of the pipe was compressive equal to 135-MPa. Axial residual stress magnitudes in the weld centerline on the internal and external surfaces of the pipe were close together. Away from the weld centerline, axial residual stresses on the internal and external surface shown opposite behavior. Thus, in the girth welding of natural gas transmission pipelines, peripheral direction on the internal surface of the pipe is the critical zone and have the highest tensile residual stresses.
... The reliability of pipelines in the energy sector, especially those carrying oil and gas, is crucial. Obeid et al. present two papers [11,12] giving information both on stresses in lined pipe during the welding process and on residual stresses in the composite pipe after it has cooled. ...
Achieving thermal systems and processes which are energy efficient and of optimised design is a goal for researchers and engineers in view of rising energy costs and decreasing targets for greenhouse gas emissions. Energy efficiency is also vital if organisations are to remain competitive. Consequently, great effort is being expended on enhancing both systems and individual components because ultimately such enhancement leads to reductions in energy consumption, costs and the impact of the systems on the environment. The papers in this special edition on energy efficient thermal systems and processes cover a very wide range of topics including the optimisation of the design or operation of systems and individual components, the use of renewable energy and low-grade heat and the production of fuels from waste. In each case the outcome of the research provides information which could be used either for reducing energy demand and emissions or for reducing environmental risks.
... However, some discrepancies between the numerical and the experimental results were found because the weld cladding layer under the low alloy steel joint was not taken into account. As a consequence of the lined pipe welding limitation, Obeid et al. [15][16][17] presented a new procedure to simulate a typical lined pipe process including the weld overlay and girth welding. Furthermore, a sensitive analysis to determine the influence of the cooling time between weld overlay and girth welding and of the welding speed has been conducted thermally and mechanically [15]. ...
... with centre that is taken as ( 0 , 0 , 0 ) [17]: ...
Experimental tests of multi-pass lined pipe welding are reported and a computational procedure for the determination of the history of temperature, strains and residual stresses is presented in this paper and validated against the experimental test results. The effect of the manufacturing process of the lined pipe on the thermo-mechanical analysis has been investigated. A 3-D FE model using ABAQUS has been developed to simulate a circumferential single-pass weld overlay (lap-weld) and two-pass girth welding (butt-weld). Thermal history and strain fields have been recorded during welding using thermocouples and high temperature strain gauges, respectively. Residual stresses have been measured using residual stress gauges, deep-hole drilling technique and the X-ray diffraction technique along the outer and inner surfaces of the lined pipe. The welding test has been repeated twice to assess the accuracy of thermal and mechanical measurements. Overall, very good correlation has been observed between the experimental and numerical results.
... One alternative is the use of a lined pipe, consisting of a thinner inner layer (the liner) and outer layer (backing steel) [3]. The liner is made of corrosion resistant alloy (CRA) such as Alloy625, 304 and 316 L stainless steel (SS) whilst the backing steel is made of low-cost carbon steel in which Magnesium Mn percentage is over 1% [4]. A lined pipe is sufficiently a good option for reasonable cost and high corrosion resistance for pipeline design life. ...
... To manufacture the lined pipe, a pre-heat treatment, which is in general known as tight fit pipe (TFP), was used. It consisted of heating up the outer pipe inside a furnace to 500°C and cooling down the inner pipe in Liquid Nitrogen to −200°C [4]. After that, the shrunk AISI304 pipe is inserted inside the heated C-Mn specimen as shown in Fig. 1. ...
An experimental and numerical investigation on the mechanical response of a lined pipe (compound pipe) under a dynamic impact is presented. The influence of the impact energy has been studied in terms of the depth of the dent formed, and of the strains and residual stresses. To this end, a three-dimensional explicit dynamic non-linear finite element model has been developed and successfully validated against the results of impact-test experiments conducted on pipes made of AISI 10305 steel, with and without the AISI304 stainless steel liner. The validation was made by comparing numerically computed strains with those measured by strain gauges, as well as in terms of permanent deformation. The model is then utilized to evaluate the residual stresses, the amount of energy dissipation and the velocity of impact process as a function of different pipes (i.e. with or without liner) and of the free drop heights.
This study presents an in-depth investigation of the influence of welding parameters (welding speed and number of passes) on the residual stress distribution in AISI 304 (Z7CN18-09) austenitic stainless-steel tubes. A three-dimensional finite element modeling (FEM), developed in ABAQUS, was implemented to simulate the circumferential welding process. The DFLUX and FILM subroutines were implemented to model the double ellipsoid mobile heat source and thermal boundary conditions, respectively. Model validation was performed by comparing weld bead profiles and thermal cycles with experimental results, showing excellent correlation (deviation < 5%). The coupled thermal and mechanical analyses allowed evaluation of the spatiotemporal evolution of the temperature field for different welding speeds (80-160-240 mm/min) and the distribution of axial and circumferential residual stresses as a function of tube thickness. The numerical results demonstrate a significant influence of these parameters on the amplitude and distribution of residual stresses, with a notable reduction in maximum stresses for optimized welding speeds and better stress homogenization with multi-pass welding.
