Investigation of Transition Temperature Tests for Line Pipe Materials

2009 ◽  
pp. 192-192-32
Author(s):  
EB Norris ◽  
RD Wylie
Keyword(s):  
Transition Temperature ◽  
Line Pipe ◽  
Pipe Materials

Predicting the Brittle-to-Ductile Transition Temperatures for Surface Cracks in Pipeline Girth Welds: It’s Better Than You Thought

2008 ◽  
Author(s):  
Gery Wilkowski ◽  
David Rudland ◽  
Do-Jun Shim ◽  
David Horsley
Keyword(s):  
Transition Temperature ◽  
Surface Crack ◽  
Master Curve ◽  
Crack Depth ◽  
Temperature Shift ◽  
Transition Temperatures ◽  
Surface Cracks ◽  
Line Pipe ◽  
Brittle To Ductile Transition ◽  
Girth Welds

A methodology to predict the brittle-to-ductile transition temperature for sharp or blunt surface-breaking defects in base metals was developed and presented at IPC 2006. The method involved applying a series of transition temperature shifts due to loading rate, thickness, and constraint differences between bending versus tension loading, as well as a function of surface-crack depth. The result was a master curve of transition temperatures that could predict dynamic or static transition temperatures of through-wall cracks or surface cracks in pipes. The surface-crack brittle-to-ductile transition temperature could be predicted from either Charpy or CTOD bend-bar specimen transition temperature information. The surface crack in the pipe has much lower crack-tip constraint, and therefore a much lower brittle-to-ductile transition temperature than either the Charpy or CTOD bend-bar specimen transition temperature. This paper extends the prior work by presenting past and recent data on cracks in line-pipe girth welds. The data developed for one X100 weld metal shows that the same base-metal master curve for transition temperatures works well for line-pipe girth welds. The experimental results show that the transition temperature shift for the surface-crack constraint condition in the weld was about 30C lower than the transition temperature from standard CTOD bend-bar tests, and that transition temperature difference was predicted well. Hence surface cracks in girth welds may exhibit higher fracture resistance in full-scale behavior than might be predicted from CTOD bend-bar specimen testing. These limited tests show that with additional validation efforts the FITT Master Curve is appropriate for implementation to codes and standards for girth-weld defect stress-based criteria. For strain-based criteria or leak-before-break behavior, the pipeline would have to operate at some additional temperature above the FITT of the surface crack to ensure sufficient ductile fracture behavior.

Fracture Behavior in West Jefferson Test Under Low-Temperature Condition for X65 Steel Pipe With High Charpy Energy: Current Activities in HLP Committee, Japan, Report 1

2016 ◽  
Author(s):  
Toshihiko Amano ◽  
Satoshi Igi ◽  
Takahiro Sakimoto ◽  
Takehiro Inoue ◽  
Shuji Aihara
Keyword(s):  
Transition Temperature ◽  
Low Temperature ◽  
Brittle Fracture ◽  
Pressure Vessel ◽  
Fracture Behavior ◽  
Line Pipe ◽  
Burst Test ◽  
Pipe Burst ◽  
Test Vessel ◽  
Fracture Appearance

This paper describes the results of pressure vessel fracture test which called West Jefferson and/or partial gas burst testing using Grade API X65 linepipe steel with high Charpy energy that exhibits inverse facture in the Drop Weight Tear Test (DWTT). A series of pressure vessel fracture tests which is as part of an ongoing effort by the High-strength Line Pipe committee (HLP) of the Iron and Steel Institute of Japan (ISIJ) was carried out at low temperature in order to investigate brittle-to-ductile transition behavior and to compare to DWTT fracture behavior. Two different materials on Fracture Appearance Transition Temperature (FATT) property were used in these tests. One is −60 degree C and the other is −25 to −30 degree C which is defined as 85 % shear area fraction (SA) in the standard pressed notch DWTT (PN-DWTT). The dimensions of the test pipes were 24inches (609.6 mm) in outside diameter (OD), 19.1 mm in wall thickness (WT). In each test, the test pipe is cooled by using liquid nitrogen in the cooling baths. Two cooling baths are set up separately on the two sides of the test vessel, making it possible to obtain fracture behaviors under two different test temperatures in one burst test. The test vessel was also instrumented with pressure transducers, thermocouples and timing wires to obtain the pressure at the fracture onset, temperature and crack propagation velocity, respectively. Some informative observations to discuss appropriate evaluation method for material resistance to brittle facture propagation for high toughness linepipe materials are obtained in the test. When the pipe burst test temperatures are higher than the PN-DWTT transition temperature, ductile cracks were initiated from the initial notch and propagated with short distance in ductile manner. When the pipe burst test temperatures were lower than the PN-DWTT transition temperature, brittle cracks were initiated from the initial notch and propagated through cooling bath. However, the initiated ductile crack at lower than the transition temperature was not changed to brittle manner. This means inverse facture occurred in the PN-DWTT is a particular problem caused by the API DWTT testing method. Furthermore, results for the pipes tested indicated that inverse facture occurred in PN-DWTT at the temperature above the 85 % FATT may not affect the arrestability against the brittle fracture propagation and it is closely related with the location of brittle fracture initiation origin in the fracture appearance of PN-DWTT.

Transition Temperature Determination for Thick Wall Line Pipe

1998 ◽  
Author(s):  
G. Demofonti ◽  
G. Junker ◽  
V. Pistone ◽  
Gerd Junker ◽  
Valentino Pistone ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Test Specimen ◽  
Laboratory Data ◽  
Full Scale ◽  
Thick Wall ◽  
Line Pipe ◽  
Brittle Transition ◽  
Brittle Transition Temperature ◽  
Ductile To Brittle Transition ◽  
Shear Area

The applicability of Drop Weight Tear Test specimen to evaluate the ductile to brittle transition temperature of thick wall pipes (30 mm and 40 mm wall thickness) has been investigated by comparing West Jefferson tests at different temperatures and laboratory data. The traditional API pressed notch specimen has been used with full and reduced thickness, together with chevron notch and weld notch starters. The different crack initiation methods have been examined with the goal of providing an easier test specimen, with reduced fracture energy. The 85% shear area transition temperature indicated by the different test specimen show a reasonable similarity, but the higher costs of preparation of the alternative notch geometries limit their adequacy in substituting the traditional pressed notch specimen. Good agreement has been found between standard DWTT specimen and full-scale test transition temperature. The results of this program together with literature data, confirm the validity of the DWTT specimen to measure the ductile to brittle transition temperature for thermomechanical rolled linepipe steels of thickness up to 40 mm. The reduced thickness specimens conservatively predicted full scale behaviour.

Determination of Brittle-to-Ductile Transition Temperatures of Large-Diameter TMCP Linepipe Steel With High Charpy Energy by Use of Modified West Jefferson Testing

2016 ◽  
Author(s):  
Y. Hioe ◽  
G. Wilkowski ◽  
M. Fishman ◽  
M. Myers
Keyword(s):  
Transition Temperature ◽  
Brittle Fracture ◽  
Large Diameter ◽  
Pipe Steels ◽  
Line Pipe ◽  
Brittle To Ductile Transition ◽  
Pipe Burst ◽  
Drop Weight Tear Test ◽  
Fracture Appearance ◽  
Shear Area

In this paper the results will be presented for burst tests from a Joint Industry Project (JIP) on “Validation of Drop Weight Tear Test (DWTT) Methods for Brittle Fracture Control in Modern Line-Pipe Steels by Burst Testing”. The JIP members for this project were: JFE Steel as founding member, ArcelorMittal, CNPC, Dillinger, NSSMC, POSCO, Tenaris, and Tokyo Gas. Two modified West Jefferson (partial gas) pipe burst tests were conducted to assess the brittle-to-ductile transition temperature and brittle fracture arrestability of two 48-inch diameter by 24.6-mm thick X65 TMCP line-pipe steels. These steels had very high Charpy energy (350J and 400J) which is typical of many modern line-pipe steels. In standard pressed-notch DWTT specimen tests, these materials exhibited abnormal fracture appearance (ductile fracture from the pressed notch prior to brittle fracture starting) that occurs with many high Charpy energy steels. Such behavior makes the transition temperature difficult to determine. The shear area values versus temperature results for these two burst tests compared to various modified DWTT specimens are shown. Different rating methodologies; DNV, API, and a Best-Estimate of steady-state fracture propagation appearance were evaluated.

Modified West Jefferson Burst Test for Assessment of Brittle Fracture Arrest in Thick-Wall TMCP Line-Pipe Steel With High Charpy Energy

2016 ◽  
Author(s):  
S. Igi ◽  
T. Sakimoto ◽  
J. Kondo ◽  
Y. Hioe ◽  
G. Wilkowski
Keyword(s):  
Transition Temperature ◽  
Brittle Fracture ◽  
Ductile Fracture ◽  
Base Metal ◽  
The Other ◽  
Line Pipe ◽  
Burst Test ◽  
Seam Weld ◽  
Shear Area ◽  
Fracture Arrest

Three partial gas pipe burst tests were conducted to assess the brittle-to-ductile transition temperature and brittle fracture arrestability of a heavy-walled TMCP line-pipe steel. This steel had a very high Charpy energy (400 J) which is typical of many modern line-pipe steels. In standard pressed-notch DWTT specimen tests this material exhibited abnormal fracture appearance (ductile fracture from the pressed notch prior to brittle fracture starting) that occurs with many high Charpy energy steels. Such behavior gives an invalid test by API RP 5L3, which makes the transition temperature difficult to determine. The first burst test was conducted in a manner that is typical of a traditional West Jefferson (partial gas vessel) burst tests. The crack was initiated in the center of the cooled vessel (with a partial air gap), but an unusual result occurred. In this test a ductile fracture just barely started from each crack tip, but one of the endcaps blew off. The pipe rocketed into the wall of a containment building. The opposite endcap impacted the wall of the building and brittle fractures started there with one coming back to the center of the vessel. The implication from this test was that perhaps initiation of the brittle fracture in the base metal gives different results than if the initial crack came from a brittle location. The second burst test used a modified West-Jefferson Burst Test procedure. The modification involved cutting a short length of pipe at the center of the vessel and rotating the seam weld to the line of crack propagation. The HAZ of the axial seam weld had a higher dynamic transition temperature. The initiation flaw was across one of the center girth welds so that one side of the initial through-wall crack had the crack tip in the base metal while the other side initiated in the seam weld HAZ. On the base metal side, the crack had about 220 mm of crack growth before reaching steady-state shear area, i.e., the shear area gradually decreased as the fracture speed was increasing. On the other side, a brittle fracture was started in the HAZ as expected, and once it crossed the other central girth weld into the base metal, the fracture immediately transformed to a lower shear area percent. These results along with those from the first burst test suggest that the DWTT specimen should have a brittle weld metal in the starter notch region to ensure the arrestability of the material. The final burst test was at a warmer temperature. There was a short length of crack propagation with higher shear area percent, which quickly turned to ductile fracture and arrested. In addition various modified DWTTs were conducted and results were analyzed using an alternative brittle fracture arrest criterion to predict pipe brittle fracture arrestability.

When Old Line Pipes Initiates Fracture in a Ductile Manner

2006 ◽  
Author(s):  
G. Wilkowski ◽  
D. Rudland ◽  
D. Rider ◽  
P. Mincer ◽  
W. Sloterdijk
Keyword(s):  
Transition Temperature ◽  
Ductile Fracture ◽  
Static Loading ◽  
Crack Depth ◽  
Temperature Shift ◽  
Charpy Impact ◽  
Pipe Material ◽  
Line Pipe ◽  
Strain Rate Effects ◽  
Constraint Effects

This paper presents a procedure to determine the lowest temperature that a ductile fracture will initiate in old (or new) pipe that behaves in a brittle manner (by Charpy testing). Over the last decade, much work has been done to assess constraint effects on the crack-driving force for specimens and cracks in pipes. The material’s transition temperature where the fracture process changes from ductile tearing to cleavage fracture at crack initiation is affected by the constraint conditions, but is a material property that cannot be determined analytically. This paper presents a methodology to account for constraint effects to predict the lowest temperature where ductile fracture initiation occurs and relates that temperature back to Charpy impact data for X60 and lower grades, particularly for older vintage linepipe materials. The method involves a series of transition temperature shifts to account for thickness effects, strain-rate effects, and constraint effects to give a master curve of transition temperatures from Charpy data to through-wall-cracked or surface-cracked pipes (with various surface-crack depth values) under quasi-static loading. These transition temperature shifts were based on hundreds of pipe tests and thousands of specimen tests over several decades of work by numerous investigators. Conducting tests on 1927 and 1948 vintage line-pipe steels subsequently validated this method. In addition, data were developed on the 1927 vintage pipe material to assess the effect of the bluntness of a corrosion flaw on the lowest temperature where ductile fracture will still occur under quasi-static loading. An addition transition temperature shift occurs as a function of the bluntness of the flaw.

Seamless Linepipe Response Under Small and Full Scale Reeling Simulation

2016 ◽  
Author(s):  
Israel Marines-Garcia ◽  
Jorge A. Aldana-Díaz ◽  
Philippe P. Darcis ◽  
Hector M. Quintanilla
Keyword(s):  
Lead Time ◽  
Cyclic Strain ◽  
Extensive Study ◽  
Full Scale ◽  
Small Scale ◽  
Pipe Material ◽  
Line Pipe ◽  
Offshore Pipelines ◽  
Ageing Condition ◽  
Pipe Materials

Offshore pipelines projects, installed by reel-laying operations, are gaining momentum due to the increasing worldwide capacity of Reel Lay Vessels. It is well known that reel-laying installation causes repeated plastic straining (cyclic deformation) and, as a consequence, cyclic strain and ageing test is usually required for qualifying line pipe materials for such installation method. This qualification is typically named reeling simulation. Reeling simulations can be made via full or small scale. In practice, full scale qualification lead time and full scale reeling simulation machines availability could be a constraint, thus, small scale reeling simulation is usually the best alternative. However, the similitude of small scale versus full scale simulations could be questioned. On this basis, an extensive study was carried-out considering tensile, toughness and sour testing, in order to evaluate the material response after reeling simulation, in order to clarify if the line pipe material will behave similarly regardless the straining method (small scale or full scale). Different small scale samples configuration for straining were tested, depending on the posterior mechanical or sour test, and two different full scale reeling simulation machines were used for plain pipes straining. Five seamless plain pipes, X65 line pipe were used for this study, with 3 (three) different outer diameters of 10.75″, 11.67″ & 16″ (273 mm, 296 mm & 406 mm). The current paper will present the main mechanical results of these materials after strain and ageing condition, comparing full and small scale straining methods.

Predicting the Fracture Initiation Transition Temperature in High Toughness, Low Transition Temperature Line Pipe With the COD Test

1974 ◽  
Vol 96 (4) ◽  
pp. 330-334 ◽  
Author(s):  
R. J. Podlasek ◽  
R. J. Eiber
Keyword(s):  
Transition Temperature ◽  
Static Loading ◽  
Crack Opening ◽  
Fracture Initiation ◽  
Full Scale ◽  
Pipe Material ◽  
Opening Displacement ◽  
Line Pipe ◽  
High Toughness ◽  
Critical Flaw

This paper describes the use of the crack opening displacement (COD) test to predict the fracture initiation transition temperature of high toughness, low-transition temperature in line pipe. A series of COD tests using t × t and t × 2t specimens made from this line pipe material. The COD test was conducted over a range of temperatures and the point where the upper shelf COD values began to decrease with decreasing temperature was defined. To verify the full-scale significance of this temperature, a series of three experiments was conducted on 48-in. (1.22m) dia line pipe to bracket the transition temperature defined in the COD Test. The results suggest that the COD transition temperature can ve used to define the fracture initiation temperature for static loading in pipe. In addition, in the transition temperature region, the full-scale results, while limited in number, suggest that the COD values could possibly be used to predict the critical flaw sizes in the pipe material.

Effects of Prestrain on Fracture Toughness and Fatigue-Crack Growth of Line Pipe Steels

2000 ◽  
Author(s):  
Naoto Hagiwara ◽  
Tomoki Masuda ◽  
Noritake Oguchi
Keyword(s):  
Fatigue Crack ◽  
Transition Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Pipe Steels ◽  
Crack Tip Opening Displacement ◽  
Line Pipe ◽  
Brittle Transition ◽  
Ductile To Brittle Transition

To investigate the failure mechanism of pipelines subjected to mechanical damage, Charpy impact, crack-tip-opening displacement (CTOD) and fatigue-crack growth tests were carried out for six series of line pipe steels with uniaxial plastic prestrain, εpr. The Charpy absorbed energy and critical CTOD (δc) decreased with increasing |εpr|; ln δc = α εpr + β. The derivative, dδc/dεpr, was dependent on the ductile-to-brittle transition temperature of the steels. In the CTOD tests, the prestrain caused ductile-to-brittle transition for the steels with a higher transition temperature. The effects of the compressive εpr on both the reduction of δc and ductile-to-brittle transition were larger than those of the tensile εpr. The compressive εpr accelerated both the fatigue-crack initiation and growth.

Fatigue Qualification of Heavy Wall Line Pipe and Girth Weld for High Pressure Applications

2013 ◽  
Author(s):  
Philippe P. Darcis ◽  
Noe Mota ◽  
Enrique Garcia ◽  
Israel Marines-Garcia ◽  
Hector M. Quintanilla ◽  
...  
Keyword(s):  
High Pressures ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Performance Comparison ◽  
Full Scale ◽  
Fatigue Performance ◽  
Thick Wall ◽  
Test Machine ◽  
Line Pipe ◽  
Pipe Materials

As the offshore oil & gas industry moves into deeper waters, more and more offshore projects, specifically the subsea, riser and flowline designs, rely on heavy wall line pipe materials. These pipe materials must be capable of operating in stringent working conditions such as high pressures, high temperatures, large deformations, fatigue loading, sour environments, etc. Within this context, ExxonMobil Development Company and Tenaris have jointly conducted a detailed technical assessment of the mechanical and fatigue performance of the newly developed heavy wall X65 line pipe (LP) developed by Tenaris. The main goal of such project is to evaluate and demonstrate via full-scale testing the fatigue performance of this new generation of heavy wall line pipe materials and the associated girth weld also recently developed by Tenaris. Although conclusive fatigue performance results at ID are not included in the present paper, the comprehensive test/qualification plan also includes a fatigue performance comparison at ID and OD. The present work clearly demonstrates weldability of this Heavy Wall X65 (273 mm OD × 46 mm WT) line pipe. A narrow-groove bevel welding procedure utilizing the STT® process for the root pass and single torch GMAW process for hot-pass, fill, and cap has been successfully developed. Four full scale fatigue tests were also successfully conducted using a resonant fatigue test machine. The presented fatigue results help demonstrate a realistic level of fatigue performance achievable with this thick wall LP/girth weld technology which will help facilitate assessment of riser/flowline design feasibility in ultra-deep water applications and/or high pressures fields.

Sign in / Sign up

Export Citation Format

Share Document