Fracture Toughness Testing of Pipeline Girth Welds

2004 ◽  
Author(s):  
G. Shen ◽  
J. A. Gianetto ◽  
R. Bouchard ◽  
J. T. Bowker ◽  
W. R. Tyson
Keyword(s):  
Fracture Toughness ◽  
Pipeline Steel ◽  
High Strength ◽  
X80 Pipeline Steel ◽  
Factors Affecting ◽  
Fracture Toughness Testing ◽  
Toughness Testing ◽  
Girth Welds ◽  
Guidelines And Recommendations ◽  
Testing Standards

The guidelines and recommendations for fracture toughness testing of pipeline girth welds outlined in CSA Z662-03, Annex K are reviewed in this work. In Annex K of CSA Z662-03, the specimen type and notch location have been grouped into four categories and the CTOD tests are to be carried out in accordance with either BSI Standard 7448 or ASTM Standard E 1290. In the present study, CTOD tests have been conducted on a manual shielded-metal-arc weld (SMAW) that was prepared in a high strength X80 pipeline steel. The experimental results obtained by applying the two testing standards are compared. The focus was to identify the differences between these two standards that may significantly affect the test results, such as the requirements for straightness of the fatigue crack, and the equations and parameters used for evaluation of CTOD. Some additional factors affecting the testing, such as selection of test specimen location and procedures for targeting specific weldment microstructures as well as the application of local compression, are also discussed. The variation of strength and toughness with clock position around the circumference of the girth welds has also been studied.

Forming mechanism of delamination cracks observed during tensile and fracture toughness testing of X70 pipeline steel

2017 ◽  
Vol 209 (1-2) ◽  
pp. 223-229 ◽  
Author(s):  
Dong-Yeob Park ◽  
Babak Shalchi Amirkhiz ◽  
Jean-Philippe Gravel ◽  
Jie Liang ◽  
Renata Zavadil ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Pipeline Steel ◽  
X70 Pipeline Steel ◽  
Forming Mechanism ◽  
Fracture Toughness Testing ◽  
Toughness Testing ◽  
Delamination Cracks

Applicability of SE(T) and SE(B) Fracture Specimens in Crack Growth Measurements of Pipeline Girth Welds

2012 ◽  
Author(s):  
Leonardo L. S. Mathias ◽  
Gustavo H. B. Donato ◽  
Claudio Ruggieri
Keyword(s):  
Crack Growth ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
High Strength ◽  
Oil And Gas Industry ◽  
Crack Growth Resistance ◽  
X80 Pipeline Steel ◽  
Fixed Amount ◽  
Resistance Curves ◽  
Girth Welds

This work presents an investigation of the ductile tearing properties for a girth weld made of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves (J-Δa curves). Use of these materials is motivated by the increasing demand in the number of applications for manufacturing high strength pipes for the oil and gas industry including marine applications and steel catenary risers. Testing of the pipeline girth welds utilized side-grooved, clamped SE(T) specimens and 3P bend SE(B) specimens with a weld centerline notch to determine the crack growth resistance curves based upon the unloading compliance (UC) method using a single specimen technique. The shallow-crack SE(B) specimen provides an R-curve which, albeit slightly more conservative, exhibits levels of J-values which are relatively comparable to the levels of J corresponding to the deeply-cracked SE(T) specimen at a fixed amount of crack growth, Δa. This experimental characterization provides additional toughness data which serve to evaluate crack growth resistance properties of pipeline girth welds using SE(T) and SE(B) specimens with weld centerline cracks.

Effects of Strain Rate on Fracture Toughness in Sour Environment

2010 ◽  
Author(s):  
Wen Guo Yuan ◽  
Da Qin Xu ◽  
You You Wu ◽  
Jens P. Tronskar
Keyword(s):  
Fracture Toughness ◽  
Strain Rate ◽  
Strain Rate Range ◽  
J Integral ◽  
Single Edge ◽  
Fracture Toughness Testing ◽  
Single Edge Notch ◽  
Edge Notch ◽  
Toughness Testing ◽  
Girth Welds

Fracture toughness testing in sour environment using Single Edge Notch Tensile (SENT) and Single Edge Notch Bend (SENB) specimens has been developed and applied by authors’ laboratory for Engineering Critical Assessment (ECA) of pipeline girth welds. The method of testing and application of fracture toughness result for ECAs of pipeline girth welds for sour service has been presented at a previous OMEA conference (paper OMAE2009-79305). The current paper presents the results of further experimental work carried out to evaluate the effect of strain rate on the fracture toughness value. A series of fracture toughness tests using SENT specimens was carried out in artificial brine sour environment (NACE solution “A” saturated with H2S) at ambient temperature. For comparison, the result from test in air condition are also presented and discussed. Following the test, the J-integral and the CTOD values were calculated and assessed. As expected, the results show significant effect of strain rate on the J integral value and the CTOD, especially for the strain rate range between 10−6/s to 10−7/s. Further experiments and studies are suggested to establish appropriate procedures and guidelines for selection of suitable strain rates for sour environment fracture toughness testing of pipeline girth welds.

Fracture Toughness Testing Using Non-Standard PCVN Specimens: Experiments and Specimen Geometry Effects on T0 Reference Temperature

2018 ◽  
Author(s):  
Vitor Scarabeli Barbosa ◽  
Claudio Ruggieri
Keyword(s):  
Fracture Toughness ◽  
Cleavage Fracture ◽  
Master Curve ◽  
High Strength ◽  
Potential Effect ◽  
Reference Temperature ◽  
Fracture Toughness Testing ◽  
Toughness Testing ◽  
Additional Support

This work addresses an experimental investigation on the cleavage fracture behavior of a high strength, low alloy structural steel using non-standard PCVN specimens. The primary purpose is to investigate the effects of increased specimen span on experimentally measured fracture toughness values and implications for the characterization of the temperature dependence of toughness based on the Master Curve methodology. Fracture toughness testing conducted on various PCVN geometries with increased specimen span extracted from an A572 Grade 50 steel plate provides the cleavage fracture resistance data in terms of the J-integral at cleavage instability, Jc. The experimental results show a potential effect of specimen span on Jc-values which can help mitigating the effects of constraint loss often observed in smaller fracture specimens. An exploratory application to determine the reference temperature, T0, derived from the Master Curve methodology also provides additional support for using non-standard bend specimens in routine fracture applications.

Fracture Toughness Testing and its Implications to Engineering Fracture Mechanics Analysis of Energy Pipelines

2018 ◽  
Author(s):  
Sergio Limon ◽  
Peter Martin ◽  
Mike Barnum ◽  
Robert Pilarczyk
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Test Data ◽  
Fracture Mode ◽  
Fracture Process ◽  
Fracture Behavior ◽  
Fracture Initiation ◽  
Fracture Toughness Testing ◽  
Final Fracture ◽  
Toughness Testing

The fracture process of energy pipelines can be described in terms of fracture initiation, stable fracture propagation and final fracture or fracture arrest. Each of these stages, and the final fracture mode (leak or rupture), are directly impacted by the tendency towards brittle or ductile behavior that line pipe steels have the capacity to exhibit. Vintage and modern low carbon steels, such as those used to manufacture energy pipelines, exhibit a temperature-dependent transition from ductile-to-brittle behavior that affects the fracture behavior. There are numerous definitions of fracture toughness in common usage, depending on the stage of the fracture process and the behavior or fracture mode being evaluated. The most commonly used definitions in engineering fracture analysis of pipelines with cracks or long-seam weld defects are related to fracture initiation, stable propagation or final fracture. When choosing fracture toughness test data for use in engineering Fracture Mechanics-based assessments of energy pipelines, it is important to identify the stage of the fracture process and the expected fracture behavior in order to appropriately select test data that represent equivalent conditions. A mismatch between the physical fracture event being modeled and the chosen experimental fracture toughness data can result in unreliable predictions or overly conservative results. This paper presents a description of the physical fracture process, behavior and failure modes that pipelines commonly exhibit as they relate to fracture toughness testing, and their implications when evaluating cracks and cracks-like features in pipelines. Because pipeline operators, and practitioners of engineering Fracture Mechanics analyses, are often faced with the challenge of only having Charpy fracture toughness available, this paper also presents a review of the various correlations of Charpy toughness data to fracture toughness data expressed in terms of KIC or JIC. Considerations with the selection of an appropriate correlation for determining the failure pressure of pipelines in the presence of cracks and long-seam weld anomalies will be discussed.

Equipment for fracture toughness testing of specimen at low temperatures

1988 ◽  
Vol 20 (5) ◽  
pp. 698-702
Author(s):  
I. D. Abushenkov ◽  
A. I. Alekseev ◽  
V. Ya. Il'ichev ◽  
N. I. Mokryi ◽  
A. I. Telegon ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Low Temperatures ◽  
Fracture Toughness Testing ◽  
Toughness Testing
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