Qualification of Local Stress Relief Heat Treatment of Double Submerged-Arc Welded DSAW Pipe for Reel-Lay Installation

2021 ◽  
Author(s):  
James Terris ◽  
Javad Safari
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Uniform Elongation ◽  
Local Stress ◽  
Cost Effective ◽  
Industry Standards ◽  
Minimum Requirements ◽  
Pipe Joints ◽  
Commercial Study ◽  
Submerged Arc

Abstract Reel-lay installation is one of the most effective methods for subsea pipeline installation. Pipes subject to reeling installation experience cyclic plastic deformations and tight control of the yield strength range, yield strength to ultimate tensile strength ratio (YS/UTS) and uniform elongation values is required on the delivered pipe. Double Submerged-Arc Weld (DSAW) pipes formed from Thermo-Mechanically Controlled Process (TMCP) plates do not normally exhibit the minimum requirements for plastic strain requirements such as minimum YS/UTS ratio or uniform elongation values. This paper describes a process for increasing the reelability of DSAW pipes. This has been achieved by induction heating of DSAW pipe ends to normalise the mechanical properties at pipe joints. The mechanical properties of the treated section have been measured and verified against design rules for reeling, based on industry standards such as DNVGL-ST-F101 [Ref. 1] and TechnipFMC supplementary requirements. The improvement in mechanical properties is measured by comparison with the as-manufactured properties of adjacent sections. A commercial study demonstrates that the locally heat-treated DSAW pipe is a cost-effective alternative to seamless pipes for reel-lay installation.

scholarly journals Effect of enhanced weld cooling on the mechanical properties of a structural steel with a yield strength of 700 MPa

2020 ◽  
Vol 2 (11) ◽  
Author(s):  
Juhani Laitila ◽  
Lassi Keränen ◽  
Jari Larkiola
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Fatigue Strength ◽  
Impact Toughness ◽  
Yield Strength ◽  
Uniform Elongation ◽  
High Strength ◽  
Low Alloy Steel ◽  
External Cooling ◽  
Welding Processes

AbstractIn this study, we present the effect of enhanced cooling on the mechanical properties of a high-strength low-alloy steel (having a yield strength of 700 MPa) following a single-pass weld process. The properties evaluated in this study include uniform elongation, impact toughness, yield, tensile and fatigue strengths alongside the cooling time of the weld. With the steel used in this study, the enhanced cooling resulted in a weld joint characterized with excellent cross-weld uniform elongation, yield and fatigue strength. The intensified cooling reduced the time it takes for the weld to reach 100 °C by around 190 s. Not only the fusion line of the weld was less pronounced, but also the grain size of the CGHAZ was greatly refined as a result of the enhanced cooling. The results indicate that combining external cooling to the welding processes can be beneficial for the studied high-strength steel.

scholarly journals Effect of initial tempers on mechanical properties of creep-aged AA2050

2019 ◽  
Vol 6 ◽  
pp. 8
Author(s):  
Yong Li ◽  
Yo-Lun Yang ◽  
Qi Rong ◽  
Zhusheng Shi ◽  
Jianguo Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Uniform Elongation ◽  
Tensile Tests ◽  
Third Generation ◽  
Rate Analysis ◽  
Precipitation Behaviour ◽  
Work Hardening Rate ◽  
Peak Aged ◽  
Creep Age Forming

The evolution of mechanical properties of a third-generation Al–Cu–Li alloy, AA2050, with different initial tempers (as-quenched WQ, naturally aged T34 and peak-aged T84) during creep-ageing has been investigated in this study. A set of creep-ageing tests was carried out under 150 MPa at 155 °C with different durations for all initial temper conditions and tensile tests were performed subsequently to acquire the main mechanical properties of the creep-aged alloys, including the yield strength, ultimate tensile strength and uniform elongation. The evolution of these mechanical properties during creep-ageing has been discussed in association with precipitation behaviour of AA2050 alloys with different initial tempers. The results indicate that the T34 alloy is the best choice for creep age forming (CAF) applications among these initial tempers, as it provides better yield strength and uniform elongation concurrently after creep-ageing. In addition, a work hardening rate analysis has been carried out for all the creep-aged alloys, helping to understand the detailed dislocation/precipitate interaction mechanisms during plastic deformation in the creep-aged AA2050 alloys with WQ, T34 and T84 initial tempers.

scholarly journals Effect of initial temper on mechanical properties of creep-aged Al-Cu-Li alloy AA2050

2018 ◽  
Vol 190 ◽  
pp. 12006
Author(s):  
Yong Li ◽  
Yo-Lun Yang ◽  
Qi Rong ◽  
Zhusheng Shi ◽  
Jianguo Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Yield Strength ◽  
Uniform Elongation ◽  
Tensile Tests ◽  
Third Generation ◽  
Rate Analysis ◽  
Precipitation Behaviour ◽  
Work Hardening Rate ◽  
Creep Age Forming

The evolution of mechanical properties of a third generation Al-Cu-Li alloy, AA2050, with different initial tempers (T34 and as-quenched (WQ)) during creep-ageing has been investigated and analysed in this study. A set of creep-ageing tests under 150 MPa at 155 °C for up to 24 h was carried out for both initial temper conditions and tensile tests were performed subsequently to acquire the main mechanical properties of the creep-aged alloys, including the yield strength, ultimate tensile strength (UTS) and uniform elongation. Precipitation behaviour of the T34 and WQ AA2050 alloys has been summarised and successfully explains the detailed evolutions of the obtained mechanical properties of the alloy with these two initial tempers during creep-ageing. The results indicate that the T34 alloy can be a better choice for creep age forming (CAF) process compared with WQ alloy, as it provides better yield strength and uniform elongation properties concurrently after creep-ageing. In addition, a work hardening rate analysis has been carried out for all the creep-aged alloys, helping to reveal the detailed dislocation/precipitates interaction mechanisms during plastic deformation in the creep-aged T34 and WQ AA2050 alloys.

Reliability Based Assessment of Minimum Wall Thickness for Reeling: A Focus on Cold Worked Pipe

2011 ◽  
Author(s):  
Daniel Smith ◽  
Tomasz Tkaczyk ◽  
Sylvain Denniel
Keyword(s):  
Yield Strength ◽  
Strain Hardening ◽  
Wall Thickness ◽  
Cost Effective ◽  
Cold Forming ◽  
Track Record ◽  
Cost Effective Alternative ◽  
Pipe Joints ◽  
Cold Worked ◽  
Tolerance Control

Pipelines installed by the reel lay method are plastically deformed during installation. The nominal level of plastic deformation is determined by the vessel equipment geometry and pipe dimensions. The natural variation of wall thickness and yield strength determines the potential differences in bending stiffness (also called mismatch) that can occur between adjacent pipe joints. These mismatches cause a localized peak in strain and can drive gross deformation of the pipe, which may result in a buckle if not addressed at the engineering stage. The slenderness of a pipe and the strain hardening capacity determines the capacity of a pipe to handle the effects of mismatches during reeling A minimum wall thickness for reeling design equation has been defined for seamless pipe and has a proven track record and demonstrable reliability. There is a recent increase in the level of interest in cold worked pipe such as HFI/HFW, which appears to be an attractive cost effective alternative to seamless pipes. HFI/HFW potentially has inferior strain hardening properties due to cold forming, but have superior tolerance control of yield strength and wall thickness. This paper presents the results of a reliability based study, demonstrating the applicability of existing minimum wall thickness for reeling criteria, when applied to HFI/HFW linepipe.

scholarly journals Mechanical Properties and Microstructure of a Duplex Nanostructure

2010 ◽  
Vol 667-669 ◽  
pp. 973-978
Author(s):  
L. Chen ◽  
Ping Jiang ◽  
Xiao Lei Wu ◽  
Mu Xin Yang ◽  
Chang Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Yield Strength ◽  
Uniform Elongation ◽  
Tensile Tests ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
Plastic Behavior ◽  
Angular Pressing ◽  
Elongation To Failure

The nanostructure was obtained in a duplex stainless steel (DSS) by means of equal channel angular pressing. The mechanical properties were characterized by uniaxial tensile tests, while the microstructure was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was shown that the yield strength in a deformed nanostructure increased significantly from 402 MPa to 1461 MPa as compared to its coarse-grained counterpart. In contrast, the uniform elongation decreased significant to only 2% together with elongation to failure of 9.8%, much lower than those of 25.4% and 42.6%. After annealing at 700°C for 10 minute, however, uniform elongation increases to 5.3% with the yield strength of 1200 MPa. TEM observation exhibited that deformation twins prevail in the austenite phase whereas the dislocations of high density present in ferrite. The plastic behavior in both phases was analyzed based on the deformation twinning and the presence of dislocation. Finally, the effect of the microstructure on mechanical properties was discussed.

Influence of the Sheet Metal Anisotropy on Polythickness of the Skin after Stretch Forming

2017 ◽  
Vol 743 ◽  
pp. 207-211 ◽  
Author(s):  
Sergey Surudin ◽  
Yaroslav Erisov ◽  
Dmitrij Chernikov
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Computer Simulation ◽  
Regression Analysis ◽  
Yield Strength ◽  
Software Package ◽  
Uniform Elongation ◽  
Optimal Combination ◽  
Stretch Forming ◽  
Forming Process

Computer simulation of the stretch forming process of the with different anisotropy of properties in the software package PAM-STAMP 2G was implemented in the work. The design of the multivariate experiment was made to analyze the effect of the anisotropy of the mechanical properties over the final polythickness of the skin after stretch forming. The regression analysis of the results was implemented after simulation, besides a mathematical model of polythickness dependence on the anisotropy of the properties was formulated. The optimal combination of Lankford coefficients, ultimate strength, yield strength and uniform elongation that minimizes polythickness of the finished skin was established.

scholarly journals Microstructure and Mechanical Properties of Pure Magnesium Subjected to Hot Extrusion

2018 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Work Hardening ◽  
Uniform Elongation ◽  
Hot Extrusion ◽  
Pure Magnesium ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The as-cast pure magnesium (Mg), with a purity of 99.99%, was hot-extruded at 300 o C to prepare a Mg bar with a diameter of 8 mm. The microstructure and mechanical properties of the sample before and after extrusion weis obviously refined with a large number of subgrains rather than equre investigated. The results show that the asextruded microstructure iaxed grains. (10 1 2) tensile twins can be observed significantly in the microstructure at this temperature. Mechanical properties including yield strength (YS), ultimate tensile strength (UTS) increased greatly but uniform elongation (UE) decreased slightly as a result of work hardening.

Effect of ethanol on the mold filling-time and mechanical properties of woven glass fiber reinforced epoxy filled with TiO2 nanoparticles

2020 ◽  
pp. 152808372097134
Author(s):  
Sherif M Youssef ◽  
M Megahed ◽  
Soliman S Ali-Eldin ◽  
MA Agwa
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Cost Effective ◽  
Mold Filling ◽  
High Viscosity ◽  
Ansys Fluent ◽  
Glass Fiber Reinforced ◽  
Filling Time ◽  
Ethanol Addition ◽  
Woven Glass Fiber

Vacuum resin infusion (VRI) is a promising technique for manufacturing complicated structural laminates. This high viscosity of nanofilled resin increases the filling time and leads to an incomplete mold filling. The mold filling time can be reduced either by making the fiber dimensions smaller than the mold (gaps around the fibers) or by adding ethanol to nanofilled epoxy. However, ethanol addition influences the mechanical properties of composite laminates. In this study, different amounts of ethanol (0.5 wt. % and 1 wt. %) were used as a diluent to both neat epoxy and epoxy filled with (0.25 wt. %) of titanium dioxide (TiO2) nanoparticles. From results, it was found that ethanol addition saves the time for neat and nanofilled epoxy by 47.1% and 24.1%, respectively. It was found that adding 0.5 wt. % of ethanol to 0.25wt. % of TiO2 nanoparticles (GT0.25E0.5) enhances the tensile and flexural strength by 30.8% and 55.9%, respectively compared with neat specimens. Furthermore, the tensile and flexural moduli increased by 62% and 72.3%, respectively. Furthermore, the mold filling time was investigated experimentally and validated numerically using ANSYS FLUENT software. The mold filling time prediction using ANSYS FLUENT can be used to avoid resin gelation before the incomplete mold filling and thus can be considered a cost-effective methodology. The results showed that the gaps around the fibers reduce the time by 178% without affecting the mechanical properties.

scholarly journals Melt- vs. Non-Melt Blending of Complexly Processable Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Nur Sharmila Sharip ◽  
Hidayah Ariffin ◽  
Tengku Arisyah Tengku Yasim-Anuar ◽  
Yoshito Andou ◽  
Yuki Shirosaki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Yield Strength ◽  
Young’S Modulus ◽  
High Molecular Weight ◽  
Melt Processing ◽  
Cellulose Nanofiber ◽  
Melt Blending ◽  
Ultra High Molecular Weight

The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.

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