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A numerical analysis of thermal phenomena occurring during lined-pipe welding is presented in this paper. Numerical models of surfaces and volumetric heat sources were used to predict the time evolution of the temperature field both in a corrosion-resistance-alloy (CRA) liner, made of SUS304 stainless steel (SS), and for the single-pass girth weldi...
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... thermal properties for the SUS304 SS liner are obtained from the study of Deng and Murakawa [2]. The 3-D finite element model is shown in Figure 1 with a total of 51840 nodes associated with 10560 fully-integrated 20 noded heat-transfer brick (i.e. solid, continuum) elements, named DC3D20 in ABAQUS, which is the code used for the analyses. ...
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Corrosion resistance has a great relevance in the selection of pipeline and riser material for new pre-salt fields due to the possibility of contaminants in the produced fluid, mainly CO2 and H2S. Carbon steel line pipes and forged materials with clad, lined or weld overlay internally have been selected for subsea pipelines and risers to withstand...
Citations
... Furthermore, for hydrocarbon pipelines where the transported crude oil is corrosive 33 with such impurities as H 2 S or CO 2 , C-Mn steel pipes are not feasible. Cladding the C-Mn 34 pipe with a thinner inner layer, which is resistant to corrosion, is a feasible alternative option, 35 so called lined pipe [1,2]. In this case, the inner layer (the liner) protects the outer pipe 36 (backing steel) from corrosion. ...
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.
... First, a weld overlay is used to seal the ends of the liner with the outer pipe. Consequently, no gap is formed between the liner and the backing steel [1,2]. A girth welding is then executed to join two adjacent specimens of the formed pipe. ...
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.
... Oil & Gas pipelines face cyclic loading generated by fluid pressure changes, especially in the case of offshore pipelines which have high internal pressure, or as a result of waves and currents, the latter possibly leading to vortex-induced vibrations [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.
... In particular, oil and gas applications depend significantly on welding. Although it is a necessary process, the main problems of using lined pipe welding arise from the high temperatures at which two completely different filler materials are deposited into two different welding grooves, the weld overlay and girth welding grooves, which in turn lead to higher residual stresses concentrated in the two fusion zones (FZ) and heat affected zones (HAZ) [1]. Therefore, predicting the locations and magnitudes of residual stresses after completing the lined pipe welding operation is important to determine the reliability and integrity of welded structures. ...
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 first one, so called weld overlay (lap-weld), is deployed to seal the liner with the outer pipe whilst the other one, known as girth welding (butt-weld), is deposited to join two specimens of lined pipe together. Therefore, the precise prediction of the thermal and residual stress fields due to the combination of two different types of circumferential welding is a major concern regarding welded lined pipes to avoid sudden failure during service. Six parametric studies have been conducted primarily to examine the influence of welding properties (weld overlay and girth welding materials), geometric parameters (weld overlay and liner) and welding process parameters (heat input) on the thermal and residual stress fields. All predicted results obtained from a 3-D FE model based on the ABAQUS code are validated against small-scale experimental results. Furthermore, in this study, the effect of mesh size has been investigated.
