Girth Welding of X100 Pipeline Steels

2002 ◽  
Author(s):  
Mark G. Hudson ◽  
Stephen A. Blackman ◽  
John Hammond ◽  
David V. Dorling
Keyword(s):  
Mechanical Property ◽  
Gas Metal Arc Welding ◽  
Data Generation ◽  
Pipeline Steels ◽  
Metal Arc Welding ◽  
Property Data ◽  
Girth Welding ◽  
Pipeline Welding ◽  
Welding Consumable ◽  
Girth Welds

Girth welding trials involving pipes of minimum proof strength 690 MPa (X100) from several linepipe manufacturers have been conducted. Welding consumable selections for the trials were based on background data generated at Cranfield University coupled with potential weld metal mechanical property requirements thought necessary for the implementation of X100 pipeline steels. Mechanised pulsed gas metal arc welding (PGMAW) and semi-automatic/ manual welding procedures were used to generate mechanical property data of mainline girth welds, tie-ins and repairs using equipment and procedures as close to current field practice as possible. The trials showed no detrimental weldability issues for the X100 steels examined. Testing comprised tensile, toughness (CVN and CTOD), hardness, side bend and nick break data generation, using pipeline welding specifications where possible.

Development and Qualification of Pipeline Welding Procedures for Strain Based Design

2007 ◽  
Author(s):  
Martin W. Hukle ◽  
Dan B. Lillig ◽  
Brian D. Newbury ◽  
John Dwyer ◽  
Agnes Marie Horn
Keyword(s):  
Large Scale ◽  
Scale Validation ◽  
Gas Metal Arc Welding ◽  
Full Scale ◽  
Pipe Material ◽  
Metal Arc Welding ◽  
Offshore Pipeline ◽  
Pipeline Welding ◽  
Girth Welds ◽  
Procedure Development

This paper reviews the specific testing methodologies implemented for the qualification of mechanized pulsed gas metal arc welding (PGMAW) procedures for strain based design applications. The qualified welding procedures were used during recent construction of an offshore pipeline subject to potential ice scour with an initial design target of 4% tensile strain capacity. This paper addresses the integrated development of linepipe specifications, large scale validation testing, weld procedure development, and finally, the verification of robustness through full scale pressurized testing of actual girth welds on project pipe material. The qualification sequence, from linepipe specification development through final full scale girth weld proof test is described.

The First L555 (X80) Pipeline in Japan

2012 ◽  
Author(s):  
Yoshiyuki Matsuhiro ◽  
Noritake Oguchi ◽  
Toshio Kurumura ◽  
Masahiko Hamada ◽  
Nobuaki Takahashi ◽  
...  
Keyword(s):  
Gas Metal Arc Welding ◽  
Control Process ◽  
High Strength ◽  
Longitudinal Direction ◽  
Full Scale ◽  
Ground Movement ◽  
Bending Test ◽  
Metal Arc Welding ◽  
S Curve ◽  
Girth Welds

The construction of the first L555(X80) pipeline in Japan was completed in autumn, 2011.In this paper, the overview of the design consideration of the line, technical points for linepipe material and for girth welds are presented. In recent years the use of high strength linepipe has substantially reduced the cost of pipeline installation for the transportation of natural gas. The grades up to L555(X80) have been used worldwide and higher ones, L690(X100) and L830(X120), e.g., are being studied intensively. In the areas with possible ground movement, the active seismic regions, e.g., pipeline is designed to tolerate the anticipated deformation in longitudinal direction. In Japan, where seismic events including liquefaction are not infrequent, the codes for pipeline are generally for the grades up to L450(X65). Tokyo Gas Co. had extensively investigated technical issues for L555(X80) in the region described above and performed many experiments including full-scale burst test, full-scale bending test, FE analysis on the girth weld, etc., when the company concluded the said grade as applicable and decided project-specific requirements for linepipe material and for girth weld. Sumitomo Metals, in charge of pipe manufacturing, to fulfill these requirements, especially the requirement of round-house type stress-strain (S-S) curve to be maintained after being heated by coating operation, which is critical to avoid the concentration of longitudinal deformation, developed and applied specially designed chemical composition and optimized TMCP (Thermo-Machanical Control Process) and supplied linepipe (24″OD,14.5∼18.9mmWT) with sufficient quality. It had also developed and supplied induction bends needed with the same grade. Girth welds were conducted by Sumitomo Metal Pipeline and Piping, Ltd and mechanized GMAW (Gas Metal Arc Welding) was selected to achieve the special requirements, i.e., the strength of weld metal to completely overmatch the pipe avoiding the concentration of longitudinal strain to the girth weld, and the hardness to be max.300HV10 avoiding HSC (Hydrogen Stress Cracking) on this portion. Both of RT (Radiographic Test) and UT (Ultrasonic Test) were carried out to all the girth welds. These were by JIS (Japan Industrial Standards) and the project-specific requirements.

Analysis and Improvement of Metal Transfer Behaviors in Consumable Double-Electrode GMAW Process

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Ming Zhu ◽  
Yu Shi ◽  
Ding Fan
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Metal Transfer ◽  
Force Balance ◽  
Current Electrode ◽  
Main Metal ◽  
Metal Arc Welding ◽  
Weld Appearance ◽  
Double Electrode ◽  
Welding Consumable

Consumable double-electrode gas metal arc welding (consumable DE-GMAW) is the efficient improvement of DE-GMAW. Due to the variety of coupled arc and metal transfer behaviors, this paper applies static force balance theory to analyze the changes in the forces acting on the main and bypass droplets separately. For main torch, the bypass arc changes the forces affecting on the main droplet, and the main metal transfer becomes more desirable. For bypass torch, with direct current electrode negative (DCEN) polarity, the volume of droplet is big and not easily transfers to the weld pool. In order to improve the bypass metal transfer, a method has been proposed which adds CO2 to pure argon shielding gas to change the forces affecting on the bypass droplet. Then, the welding experiment is carried out to test the effectiveness of this method. It is found that bypass droplet transfers easily and the diameter of bypass droplet is decreased significantly. Also a good weld appearance is acquired.

Development of Optimized Weld Metal Chemistries for Pipeline Girth Welding of High Strength Line Pipe

2008 ◽  
Author(s):  
Susan R. Fiore ◽  
James A. Gianetto ◽  
Mark G. Hudson ◽  
Suhas Vaze ◽  
Shuchi Khurana ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Yield Strength ◽  
Weld Metal ◽  
High Strength ◽  
Process Variations ◽  
Line Pipe ◽  
Girth Welding ◽  
Dimensional Finite Element ◽  
Initial Work ◽  
Girth Welds

The primary objectives of this program were to provide a better understanding of the factors that control strength and toughness in high strength steel girth welds and to develop optimized welding consumables and welding procedures for high strength pipelines. The initial work on the program involved developing cooling rate models so that optimized weld metal compositions for high-strength pipelines could be developed, ensuring that the ideal balance of strength and ductility, together with tolerance to process variations and resistance to hydrogen cracking is achieved. The model, which was developed under a companion program, uses a two-dimensional finite element approach. Complete details can be found in Reference [1]. The model predicts the cooling rates during various weld passes in narrow groove welding of X80 and X100 pipes. Using this model, along with experimental datasets, a neural network model was developed which has been used to predict weld metal properties for various weld metal compositions. Based on the predictions, eight target compositions were selected and were manufactured by one of the team partners. The results of mechanical property testing showed that it was possible to develop weld metal compositions which exceeded the target yield strength of 820 MPa and also provided excellent toughness (>50J at −60°C). It was also found that the weld metal yield strength measured close to the ID of the pipe was significantly higher than that which was measured closer to the OD of the pipe. Complete mechanical property results, including results for round-bar and strip tensiles, CVN impact toughness, microhardness and more, are presented.

scholarly journals Effect of Different Filler Wires on Mechanical Property and Conductivity of Aluminum-Copper Joints

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3648
Author(s):  
Hengming Zhang ◽  
Yu Shi ◽  
Yufen Gu ◽  
Chunkai Li
Keyword(s):  
Mechanical Property ◽  
Tensile Strength ◽  
Intermetallic Compounds ◽  
Arc Welding ◽  
Pure Aluminum ◽  
Gas Metal Arc Welding ◽  
Interface Zone ◽  
Metal Arc Welding ◽  
Different Types ◽  
Double Electrode

The 1060 aluminum and T2 copper were joined by the pulsed double electrode gas metal arc welding (DE-GMAW) brazing method by using four types of filler wires, namely pure aluminum (Al) ER1100, aluminum-magnesium (Al–Mg) ER5356, aluminum-silicon (Al–Si) ER4043, and Al–Si ER4047, respectively. The effects of different types of filler wires on intermetallic compounds, microhardness tensile strength, and conductivity of joints were investigated. The results showed that a lot of brittle intermetallic compounds laying in the copper side brazing interface zone were generated using pure Al, Al–Mg, and Al–Si filler wires, which caused the change of microhardness, tensile strength, and the conductivity of joints. Meanwhile, with the increase in Si elements contents for Al–Sifiller wires, the thickness of the intermetallic compound layers decreased obviously, which was only up to 3 µm and the conductivity of the joints decreased. In addition, the microhardness, tensile strength, and the conductivity of the joints, when using Al–Sifiller wires, was higher than that using pure Al and Al–Mg filler wires. Hence, in comparison to the pure filler wires and Al–Mg filler wires, the Al–Si filler wires were more suitable for Al–Cu joints by DE-GMAW as Si element content was lower.

Structures and Properties of X80 Pipeline Girth Welds for Different Welding Procedures

2012 ◽  
Author(s):  
Xiaodong He ◽  
Yangqin Liu ◽  
Lixia Zhu ◽  
Ke Tong ◽  
Xiaodong Shao
Keyword(s):  
Tensile Properties ◽  
Welded Joints ◽  
Arc Welding ◽  
Mass Fraction ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Single Wire ◽  
Metal Arc Welding ◽  
The Difference ◽  
Girth Welds

The X80 girth welds were produced by solid-wire gas metal arc welding (GMAW) and shield metal arc welding (SMAW) using two welding consumables respectively, which contained different mass fraction of C, Mo and Ni. The tensile properties, notch toughness, hardness, and microstructures of welded joints were evaluated. The results indicate that high strength and good toughness of welded joints can be achieved. But the tensile properties of all weld metal of GMAW and SMAW process were evidently different because of the difference of mass fraction of C, Mo, Ni. The strength reduced slightly in softening zone of HAZ. Using welding consumable which contain higher Mo additions, the microstructure in weld seam and fusion zones were IAF+GB and GB+M respectively. Furthermore, the mechanical properties of X80 pipeline welded by single wire welding and double wire welding respectively have been compared. The double wire welds exhibited lower yield strength but higher toughness compared to the corresponding single wire welds.

Girth Weldability Evaluation of SAWH Pipes Produced From 23.7mm Thick, High-Nb Containing X70 Linepipe Steel

2014 ◽  
Author(s):  
Özlem E. Güngör ◽  
Martin Liebeherr ◽  
Hervé Luccioni
Keyword(s):  
Gas Metal Arc Welding ◽  
Construction Companies ◽  
Controlled Processing ◽  
Metal Arc Welding ◽  
Increasing Demand ◽  
Girth Welds ◽  
Welding Procedure ◽  
Linepipe Steels ◽  
Linepipe Steel

In the energy market, there is an increasing demand for oil & gas transmission pipelines with larger wall thicknesses and from higher strength linepipe steels. Addition of niobium (Nb) to the steel chemistry in combination with thermo-mechanical controlled processing allow increasing the thickness of the linepipe steels on coil while maintaining good strength and toughness. However, pipeline construction companies often indicate their concerns about the weldability of high Nb containing linepipe steels and in addition, Nb levels are restricted in some of the steel specifications for linepipe applications. In this study, field weldability of industrially produced helical pipes made from 23.7 mm thick, high Nb containing X70 linepipe steel was evaluated. Welding procedure development was realized for narrow-groove mechanized gas metal arc welding (GMAW). Characterization of the girth welds produced revealed the suitability of the material for typical field welding procedures for onshore pipe laying. The details and the results of the investigations are presented and discussed in the paper.

Integration of Welding, NDT, Mechanical Testing and Field Control When Using an ECA Flaw Acceptance Criteria in Pipeline Construction

2018 ◽  
Author(s):  
Junfang Lu ◽  
Bob Huntley ◽  
Luke Ludwig ◽  
Axel Aulin ◽  
Andy Duncan
Keyword(s):  
Mechanical Testing ◽  
Gas Metal Arc Welding ◽  
Probability Of Detection ◽  
Destructive Testing ◽  
Acceptance Criteria ◽  
Pipeline Construction ◽  
High Productivity ◽  
Metal Arc Welding ◽  
Field Control ◽  
Girth Welds

The fracture mechanics based engineering critical assessment (ECA) method has been accepted as a fitness for service (FFS) approach to defining weld flaw acceptance criteria for pipeline girth welds. Mechanized gas metal arc welding (GMAW) processes are commonly used in cross country pipeline girth weld welding because of the advantages in good quality and high productivity. With the technical advancements of non-destructive testing (NDT) techniques, automated ultrasonic testing (AUT) has greatly improved flaw characterization, sizing and probability of detection during weld inspection. Alternative weld flaw acceptance criteria are permitted in pipeline construction code to assess the acceptability of mechanized girth welds using an ECA. The use of an ECA based weld flaw acceptance criteria can significantly reduce the construction cost. Mechanized girth weld acceptance criteria have been progressively transitioned from workmanship standards into using fitness for service based ECAs. To successfully deliver an ECA on a pipeline project, a multidisciplinary approach must be taken during the welding design and construction stages. Welding, NDT, mechanical testing and field control are all integral elements of pipeline construction. All these four elements have to be fully integrated in order to implement the ECA and achieve the overall integrity of a pipeline. The purpose of this paper is to discuss the importance of the integration of these four elements necessary for proper implementation of the ECA weld flaw acceptance criteria.

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