scholarly journals Bond Formation Mechanism for Resistance Welding of X70 Pipeline Steel

2020 ◽  
Vol 99 (8) ◽  
pp. 209s-223s
Author(s):  
RANGASAYEE KANNAN ◽  
◽  
LEIJUN LI ◽  
LULU GUO ◽  
NEIL ANDERSON ◽  
...  
Keyword(s):  
Mushy Zone ◽  
Pipeline Steel ◽  
Microstructure Characterization ◽  
Resistance Welding ◽  
Delta Ferrite ◽  
Weld Formation ◽  
Seam Weld ◽  
Resistance Weld ◽  
Welded Pipe ◽  
First Time

A Gleeble® thermo-mechanical simulator combined with microstructure characterization using a field emission scanning electron microscope was used to provide insights into the seam weld formation during resistance welding (RW). Gleeble® was used to physically/microstructurally simulate the seam weld formation during RW for the first time. It was found that a peak temperature of 1500˚C and 10-mm stroke produced a microstructure in the solid-state bondline, the flash, and the heat-affected zone similar to the resistance welded pipe manufactured in an industrial scale. Using the force response obtained during seam weld formation in Gleeble®, microstructure characterization of the seam weld, and thermodynamic calculations, it is pro-posed the seam weld in a resistance weld consists of a mushy zone with delta ferrite and solute-enriched liquid, which solidifies into austenite, and on post welding cooling, transforms into ferrite and stringers of M/A, respectively. The presence of a mushy zone in the weld joints provides a physical explanation for the “decarburization” phenomenon observed in the seam of resistance welds.

Effect of Reheating and Deformation Processes on DWTT Performance for Heavy Gauge Pipeline Steel

2018 ◽  
Vol 921 ◽  
pp. 149-156
Author(s):  
Chuan Guo Zhang ◽  
Qi Jie Zhai ◽  
Lei Zheng
Keyword(s):  
Steel Plate ◽  
Pipeline Steel ◽  
Reduction Ratio ◽  
Toughening Mechanism ◽  
Soaking Time ◽  
Single Pass ◽  
Fracture Appearance Transition Temperature ◽  
Fracture Appearance ◽  
Deformation Processes ◽  
Welded Pipe

DWTT (Drop weigh tear test) is an effective way to evaluate the fracture propagation for pipeline steel. The effects of slab reheating temperature, soaking time, single pass reduction ratio during recrystallization zone rolling and transfer bar ratio during non-recrystallization zone rolling on DWTT performance were studied for heavy gauge pipeline steel. And the grain refinement and toughening mechanism were discussed. It was found that the grain in the core of the plate can be refined by reducing the reheating temperature, increasing the single pass reduction ratio during recrystallization zone rolling and setting suitable transfer bar ratio during non-recrystallization zone rolling, which promote the DWTT property improvement for heavy gauge pipeline steel. The 30.9mm heavy gauge pipeline steel plate was industrial produced and the X70 UOE welded pipe with dimension in Φ1219×30.9mm was manufactured. The DWTT 85%FATT (fracture appearance transition temperature) of pipe body is as low as -20°C.

Microstructure and Properties of Longitudinal Submerged Arc Welded Linepipes for Deep-Sea Pipeline

2014 ◽  
Vol 997 ◽  
pp. 409-414 ◽  
Author(s):  
Ji Xiang Gao ◽  
Lie Jun Li ◽  
Jian Feng Li ◽  
Xiao Ning Wang ◽  
Shao Jun Wei
Keyword(s):  
Deep Sea ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
Test Methods ◽  
Granular Bainite ◽  
Thick Wall ◽  
Fine Crystal ◽  
Microstructure And Properties ◽  
Welded Pipe ◽  
Submerged Arc

This paper provides description of deep-sea JCOE process of longitudinal submerged-arc welded pipe.The test methods including optical microscopy and tensile,toughness,drop weight tear are applied, the microstructure and properties of deep-sea pipeline steel and deep longitudinal submerged arc welded pipe with thick wall are studied. The results indicates that pipeline steel of substrate organization to acicular ferrite mainly and deep with longitudinal submerged-arc welded thick wall pipe welding HAZ of rough crystal area and fine crystal area respectively main for granular bainite and associate polygon ferrite organization; Deep-sea LSAW steel pipe has reasonable control parameters for process, and its performance meets DNV-OS-F101:2007 specification and user project technology conditions,used for materiels of pipeline steel for China deep-sea oil and gas pipeline project.

Microstructure and Mechanical Properties of a Cold-Rolled Medium Manganese Steel with Delta Ferrite

2015 ◽  
Vol 816 ◽  
pp. 750-754 ◽  
Author(s):  
Zhi Ping Hu ◽  
Yun Bo Xu ◽  
Xiao Dong Tan ◽  
Xiao Long Yang ◽  
Yong Mei Yu
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Microstructure Characterization ◽  
Manganese Steel ◽  
Electron Backscattered Diffraction ◽  
Delta Ferrite ◽  
Tension Tests ◽  
Before And After ◽  
Cold Rolled

In this paper, a quenching and tempering process was applied to the cold-rolled medium Mn steel with the delta ferrite (Fe-0.18C-6.4Mn-2.8Al). Microstructure characterization was carried out by means of optical microscope, scanning electron microscope (SEM) equipped with electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). Mechanical properties tests were carried out by uniaxial tension tests. The microstructure characterization results revealed that the steel possessed a complex microstructure composed of three phases (austenite, martensite and delta ferrite). The volume fractions of austenite before and after a deformation were determined by X-ray diffraction (XRD). The XRD results indicated that the amount of austenite reached up to 20 vol.% and the TRIP effect occurred quite apparently. The mechanical property results showed that the steel possessed adequate ultimate tensile strength of 800MPa and excellent elongation of 25%. The outstanding combination of strength and ductility with the product of strength and elongation (PSE) reaching up to over 20GPa% indicates that the steel has a bright application prospect.

Identifying and Sizing Axial Seam Weld Flaws in ERW Pipe Seams and SCC in the Pipe Body Using Ultrasonic Imaging

2016 ◽  
Author(s):  
Harvey Haines ◽  
Lars Hörchens ◽  
Pushpendra Tomar
Keyword(s):  
New Technologies ◽  
Ultrasonic Imaging ◽  
Three Dimensional ◽  
Low Frequency ◽  
Fatigue Cracking ◽  
Seam Weld ◽  
Current State ◽  
Pressure Cycle ◽  
Ultrasonic Phased Array ◽  
Resistance Weld

A significant portion of the global energy pipeline infrastructure is constructed with pipe materials manufactured using the Electric Resistance Weld (ERW) process. The longitudinal seam of these ERW pipelines may contain manufacturing flaws and anomalies that can grow over time through pressure cycle fatigue and result in a pipeline integrity failure. These flaws/anomalies can be present in both vintage pipe (generally pre-1970) manufactured using a low frequency ERW process and more modern pipe that is manufactured using a high frequency ERW process. ERW seam anomalies are challenging to detect, discriminate, and size with current In-Line Inspection and In-Ditch NDE inspection technologies, which is driving the industry to better understand current inspection industry performance and to develop new technologies for ERW seam anomaly inspection. Ultrasonic (UT) imaging using inverse wave field extrapolation (IWEX) is an emerging NDE technique that is being applied to improve discrimination and sizing of anomalies in pipelines. This paper will describe the IWEX development, the challenges related to seam weld integrity and assessment and SCC assessment, and results from studies to evaluate performance. Ultrasonic imaging is also compared to the current state-of-the-art techniques such as ultrasonic phased array (PA). A goal of the project is to produce images capable of discriminating cold welds, surface breaking hook cracks, non-surface breaking upturned fiber indications, poor trim, offset plate edges, and anomalies with fatigue cracking. The goal is to size all of the cracks in a SCC colony and produce a three-dimensional map of the area. In mapping these anomalies the sizing needs to be sufficiently accurate to qualify in-line inspection tools used for crack inspection.

Ultrasonic NDE Technology Comparison for Measurement of Long Seam Weld Anomalies in Low Frequency Electric Resistance Welded Pipe

2018 ◽  
Author(s):  
Luis Torres ◽  
Matthew Fowler ◽  
Jason Bergman
Keyword(s):  
Ultrasonic Testing ◽  
Low Frequency ◽  
Management Approach ◽  
Electric Resistance ◽  
Seam Weld ◽  
Tool Performance ◽  
Ultrasonic Nde ◽  
Welded Pipe ◽  
Continuous Technology ◽  
Non Destructive

In the pipeline industry, a widely accepted methodology for integrity crack management involves running ultrasonic In-Line Inspection (ILI) technologies. After an ILI tool run is completed, the performance of the tool is typically validated by excavating the pipeline and conducting in-the-ditch investigations. Ultrasonic Non-Destructive Evaluation (NDE) techniques are used in the field to characterize and measure crack-like features. These in-the-ditch measurements are compared back to ILI results in order to validate tool performance and drive continuous technology improvements. Since validation of the ILI tool relies on NDE measurements, acquiring accurate and representative data in the field is a critical step in this integrity crack management approach. Achieving an accurate field inspection comes with its challenges, some of which relate to complex long seam weld conditions present in older vintage pipelines including: weld misalignment, weld trim issues, and dense populations of manufacturing anomalies. In order to better understand the challenges associated with complex long seam weld conditions, an evaluation and comparison of the performance of NDE technologies currently available was conducted. In this study, a portion of a Canadian pipeline with complex long seam weld conditions was cut-out and removed from service. Multiple NDE crack inspection technologies and methods from three different vendors were used to assess the condition of the long seam weld. Conventional Ultrasonic Testing (UT), Phased Array Ultrasonic Testing (PAUT), Time of Flight Diffraction (TOFD), and variations of Full Matrix Capture Ultrasonic Testing (FMCUT) were used to assess the long seam weld and their results were compared. The performance of all NDE technologies is baselined by comparing them with destructive examination of sections of the long seam weld. The newer NDE assessment methodologies were shown to be consistently more accurate in characterizing long seam features.

Stress Intensity Factor Solutions for Crack-Like Anomalies in ERW Seam Welded Pipe

2017 ◽  
Author(s):  
Jennifer O’Brian ◽  
Richard Olson ◽  
Bruce Young
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Transportation Safety ◽  
Department Of Transportation ◽  
Axial Crack ◽  
Resistance Weld ◽  
Welded Pipe ◽  
Weld Corrosion ◽  
Longitudinal Seam

In response to the National Transportation Safety Board (NTSB) Recommendation P-09-1, the Department of Transportation (DOT) Pipeline and Hazardous Material Safety Administration (PHMSA) initiated a comprehensive study to identify actions that could be implemented by pipeline operators to significantly reduce longitudinal seam failures in electric resistance weld (ERW) pipe. As part of the project, Task 3 in Phase II was designed to determine more appropriate stress intensity factor solutions for non-standard, axial, crack-like anomalies in ERW seam-welded pipe. The purpose of this paper is to provide an overview of the normalized stress intensity factor solutions for cold weld (CW), selected seam-weld corrosion (SSWC), and hook crack type anomalies. ERW seams with and without weld caps are also included. The limitations on design space are discussed in the context of presenting results and interpolation and extrapolation schemes beyond that space with infinitely long solutions used as a boundary value. Results are presented in the form of surface plots for various combinations of parameters. The reports generated during the project are publicly available and are located on the following PHMSA website: http://primis.phmsa.dot.gov/matrix/PrjHome. rdm?prj=390.

Remaining Life Assessment of ERW Flaws: A Case Study

2012 ◽  
Author(s):  
Pablo Cazenave ◽  
Samarth Tandon ◽  
Katina Tinacos ◽  
Ming Gao ◽  
David C. Katz ◽  
...  
Keyword(s):  
Low Frequency ◽  
Management Program ◽  
Life Assessment ◽  
Seam Weld ◽  
Natural Gas Pipelines ◽  
Integrity Management ◽  
Remaining Life Assessment ◽  
Welded Pipe ◽  
Weld Area

Recent failures in seam weld pipe have raised concerns within the pipeline industry over the integrity of such welded pipe. Low-Frequency (LF) Electric Resistance Welded (ERW) pipe manufactured prior to 1970, in particular, can be susceptible to failures caused by hook cracks, lack of fusion and other planar defects should the weld area exhibit low toughness. Integrity management regulations and Pipeline operators are evaluating potential methodologies to address and mitigate the LF-ERW seam weld threat. A program has been initiated at Williams Northwest Pipeline GP (NWPGP) to address the integrity management of its pre-70s ERW pipelines. In this case study, as part of an overall integrity management program, a hydrostatic test and fatigue analysis based methodology for addressing the LF-ERW seam weld threat is presented. The methodology was applied to 15 pre-1970’s natural gas pipelines. The results and findings are summarized in terms of the integrity threat mitigation and maintenance strategies.

Characterization of Motion of Dendrite Fragment by X-Ray Radiography on Earth and under Microgravity Environment

2014 ◽  
Vol 790-791 ◽  
pp. 311-316 ◽  
Author(s):  
Georges Salloum-Abou-Jaoude ◽  
Henri Nguyen-Thi ◽  
Guillaume Reinhart ◽  
Ragnvald H. Mathiesen ◽  
Gerhard Zimmermann ◽  
...  
Keyword(s):  
Mushy Zone ◽  
Liquid Fraction ◽  
Microgravity Environment ◽  
Bulk Liquid ◽  
In Situ Observation ◽  
X Ray ◽  
Solidification Microstructures ◽  
First Time

In the frame of ESA-MAP (Microgravity Application Promotion) project entitled XRMON (In situ X-Ray MONitoring of advanced metallurgical processes under microgravity and terrestrial conditions), a microgravity (μg) experiment in the XRMON-GF (Gradient Furnace) setup was successfully launched in 2012 on board MASER 12 sounding rocket. During this experiment, in situ and real time observations of the formation of the solidification microstructures in diffusive conditions were carried out for the first time by using X-ray radiography. In addition, two reference experiments with the same control parameters but in ground-based conditions were performed to enable us a direct comparison with the μg experiment and therefore to enlighten the effects of gravity upon microstructure formation. This communication reports on fragmentation phenomenon observed during those experiments. For 1g upward solidification, fragmentations mainly take place in the upper part of the mushy zone. After their detachments, dendrite fragments are carried away by buoyancy force in the bulk liquid where they are gradually remelted. For μg experiment and horizontal solidification, this type of fragmentation is not observed. However, a great number of fragmentations are surprisingly revealed by in situ observation in the deep part of the mushy zone, when the liquid fraction is very small. Moreover, as soon as they are detached, the dendrite fragments move toward the cold part of the mushy zone, even in the case of μg experiment. The observations suggest that sample shrinkage may be at the origin of this fragment motion.

CTOA Measurements of Welds in X100 Pipeline Steel

2008 ◽  
Author(s):  
Elizabeth Drexler ◽  
Philippe Darcis ◽  
Christopher McCowan ◽  
J. Matthew Treinen ◽  
Avigdor Shtechman ◽  
...  
Keyword(s):  
Stress Field ◽  
Base Metal ◽  
Pipeline Steel ◽  
Base Material ◽  
Fusion Line ◽  
Opening Angle ◽  
Seam Weld ◽  
Weld Material ◽  
X100 Pipeline Steel ◽  
Girth Welds

A suite of tests characterizing X100 pipeline steels was initiated at the National Institute of Standards and Technology (NIST) in Boulder. Part of the test matrix included testing the toughness of the base metal, welds, and heat-affected zones (HAZ) by use of modified double cantilever beam specimens for crack tip opening angle (CTOA) testing. The thickness of the test section was either 3 mm or 8 mm. Girth welds perpendicular to the growing crack, and seam welds and their HAZ parallel with the crack, were tested with a crosshead displacement rate of 0.02 mm/s (with the exception of one girth weld specimen for each thickness, which were tested at 0.002 mm/s). Analysis of the data revealed some general differences among the weld specimens. The tests where the crack ran perpendicular to the girth weld demonstrated changes in CTOA and crack growth rate as the crack moved through the base metal, HAZ, and weld material. We observed the values for CTOA increasing and the crack propagation slowing as the crack moved through the weld and approached the fusion line. The stress field appeared to be strongly influenced by the thin HAZ, the fusion line, and the tougher base material. Consequently, the CTOA of the HAZ associated with the girth weld was larger than that of the seam-weld HAZ. It was not possible to obtain CTOA data for the seam weld, with the crack parallel within the weld, because the crack immediately diverted out of the stronger weld material into the weaker HAZ. CTOA values from both girth welds and seam-weld HAZ were smaller than those of the base material. The 8 mm thick specimens consistently produced larger CTOA values than their 3 mm counterparts, introducing the possibility that there may be limitations to CTOA as a material property. Further tests are needed to determine whether a threshold thickness exists below which the constraints and stress field are sufficiently changed to affect the CTOA value.

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