Crack Growth Testing of an X80 Pipeline Girth Weld Using SE(T) and SE(B) Fracture Specimens

2012 ◽  
Author(s):  
Leonardo L. S. Mathias ◽  
Diego F. S. Burgos ◽  
Gustavo H. B. Donato ◽  
Marcelo Paredes ◽  
Claudio Ruggieri
Keyword(s):  
Crack Growth ◽  
Pipeline Steel ◽  
Oil And Gas Industry ◽  
Crack Growth Resistance ◽  
Homogeneous Material ◽  
Single Edge ◽  
X80 Pipeline Steel ◽  
Resistance Curves ◽  
Girth Welds ◽  
Fracture Specimens

Accurate measurements of fracture resistance properties, including crack growth resistance curves for pipeline girth welds, become essential in defect assessment procedures of the weldment region and the heat affected zone, where undetected cracklike defects (such as lack of penetration, deep undercuts, root cracks, etc.) may further extend due to to high tension stresses and strains. 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 single edge notched tensiles (SE (T)) specimens and three-point (3P) bend single edge 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. Recently developed compliance functions and η-factors applicable for SE (T) and SE(B) fracture specimens with homogeneous material and overmatch welds are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records. 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.

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.

Experimental Evaluation of J Resistance Curves for Ductile Steels Using SE(T) Fracture Specimens

2007 ◽  
Author(s):  
Sebastian Cravero ◽  
Claudio Ruggieri ◽  
Roberto Piovatto ◽  
Waldek W. Bose ◽  
Dirceu Spinelli
Keyword(s):  
Crack Growth ◽  
Oil And Gas ◽  
Pipeline Steel ◽  
High Strength ◽  
Oil And Gas Industry ◽  
Crack Size ◽  
Crack Growth Resistance ◽  
Pipeline Steels ◽  
Resistance Curves ◽  
Fracture Specimens

This work presents an investigation of the ductile tearing properties for an API 5L X60 pipeline steel using experimentally measured crack growth resistance curves (J-R curves). Use of these materials are motivated by the increasing demand in the number of applications for manufacturing high strength pipes for the Brazilian oil and gas industry including marine applications and steel catenary risers. Testing of the pipeline steels employed side-grooved SE(T) specimen with varying crack size to determine the J-R curves based upon the unloading compliance method using a single specimen technique. Recent developed compliance functions and eta-factors applicable for SE(T) fracture specimens are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records. This experimental characterization provides additional toughness data which serve to evaluate crack growth resistance properties of pipeline steels using SE(T) specimens with varying geometries.

Numerical Investigation of Ductile Crack Growth Behavior at Different Locations of Weld Joint for X80 Pipeline Steel

2019 ◽  
Author(s):  
Bin Qiang ◽  
Xin Wang
Keyword(s):  
Crack Growth ◽  
Weld Joint ◽  
Pipeline Steel ◽  
Crack Growth Behavior ◽  
Ductile Crack ◽  
Single Edge ◽  
X80 Pipeline Steel ◽  
Gtn Model ◽  
Ductile Crack Growth ◽  
Resistance Curves

Abstract The finite element method (FEM) based on the Gurson–Tvergaard–Needleman (GTN) model was used to investigate the ductile crack growth behavior at different weld joint locations in X80 pipeline steel. The X80 weld joints are inhomogeneous and can be divided into five different zones. By fitting the results of uniaxial tension and single-edge notched bending tests, the GTN model parameters were determined using FEM in consideration of the inhomogeneity of the weld joint. The calibrated GTN model was then used to analyze the fracture toughness in single-edge notched tension tests. The results show that the different weld joint zones produce different mechanical properties and crack growth resistance curves. To accurately assess the integrity of X80 weld joints, the calibrated GTN model is a reasonable method for obtaining fracture toughness data and resistance curves for different joint locations under different loading conditions.

scholarly journals Numerical Investigation of Strength Mismatch Effect on Ductile Crack Growth Resistance in Welding Pipe

2020 ◽  
Vol 10 (4) ◽  
pp. 1374
Author(s):  
Lin Su ◽  
Jie Xu ◽  
Wei Song ◽  
Lingyu Chu ◽  
Hanlin Gao ◽  
...  
Keyword(s):  
Crack Growth ◽  
Fracture Resistance ◽  
Crack Growth Resistance ◽  
Ductile Crack ◽  
Single Edge ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Ductile Crack Growth ◽  
Welding Pipe ◽  
Resistance Curves

The effect of strength mismatch (ratio between the yield stress of weld metal and base metal, My) on the ductile crack growth resistance of welding pipe was numerically analyzed. The ductile fracture behavior of welding pipe was determined while using the single edge notched bending (SENB) and single edge notched tension (SENT) specimens, as well as axisymmetric models of circumferentially cracked pipes for comparison. Crack growth resistance curves (as denoted by crack tip opening displacement-resistance (CTOD-R curve) have been computed using the complete Gurson model. A so-called CTOD-Q-M formulation was proposed to calculate the weld mismatch constraint M. It has been shown that the fracture resistance curves significantly increase with the increase of the mismatch ratio. As for SENT and pipe, the larger My causes the lower mismatch constraint M, which leads to the higher fracture toughness and crack growth resistance curves. When compared with the standard SENB, the SENT specimen and the cracked pipe have a more similar fracture resistance behavior. The results present grounds for justification of usage of SENT specimens in fracture assessment of welding cracked pipes as an alternative to the traditional conservative SENB specimens.

Evaluation of Crack Growth Resistance Curves for Pipeline Steels Using Constraint Designed Fracture Specimens

2006 ◽  
Author(s):  
Sebastian Cravero ◽  
Claudio Ruggieri
Keyword(s):  
Crack Growth ◽  
Estimation Procedure ◽  
Standard Test ◽  
Crack Growth Resistance ◽  
Test Procedures ◽  
Pipeline Steels ◽  
Wide Range ◽  
Resistance Curves ◽  
Unloading Compliance ◽  
Fracture Specimens

This work provides an estimation procedure to determine J-resistance curves for SE(T) fracture specimens using the unloading compliance technique and the eta-method. In the present study, attention is directed to pin-loaded SE(T) specimens with varying geometry and crack sizes but representative solutions are also included for clamped SE(T) specimens. A summary of the methodology upon which J and crack extension are derived sets the necessary framework to determine crack resistance data from the measured load vs. displacement curves. The extensive plane-strain analyses enable numerical estimates of the nondimensional compliance, μ, and parameters η and γ for a wide range of specimen geometries and material properties characteristic of structural and pipeline steels. Laboratory testing of an API 5L X60 steel at room temperature using pin-loaded SE(T) specimens with side-grooves provide the load-displacement data needed to validate the estimation procedure for measuring the crack growth resistance curve for the material. The results presented here produce a representative set of solutions which lend further support to develop standard test procedures for constraint-designed SE(T) specimens applicable in measurements of crack growth resistance for pipelines.

Fracture Toughness Testing of an Overmatched Pipe Girth Weld Using Clamped SE(T) Specimens

2019 ◽  
Author(s):  
Claudinei Ferreira ◽  
Diego F. S. Burgos ◽  
Claudio Ruggieri
Keyword(s):  
Crack Growth ◽  
Base Material ◽  
Welding Process ◽  
High Strength ◽  
Crack Growth Resistance ◽  
Ductile Tearing ◽  
Average Crack ◽  
Toughness Testing ◽  
Resistance Curves ◽  
Girth Welds

Abstract This work presents an investigation of the ductile tearing properties for a girth weld made of an ASTM A106 Gr C steel using the SMAW welding process with a low hydrogen E7018 electrode thereby resulting in a weld with high strength overmatching with respect to the base material. Testing of the pipe girth welds employed side-grooved, clamped SE(T) 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. Recently developed compliance functions and η-factors applicable to weld centerline notched SE(T) specimens are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records. While the UC procedure resulted in measured crack extensions for the tested specimens with weld centerline notch that underestimated the 9-point average crack extension, our preliminary results demonstrate the capability of the methodology in describing crack growth resistance behavior which serves as a basis for ductile tearing assessments in ECA procedures applicable to overmatched girth welds and similar structural components.

Effect of Residual Stresses on Ductile Crack Growth in Pipeline Steel

2016 ◽  
Vol 850 ◽  
pp. 403-408
Author(s):  
Xiao Min Zhuo ◽  
Jie Xu ◽  
Peng Peng Li ◽  
Yu Fan ◽  
Zhi Sun
Keyword(s):  
Residual Stresses ◽  
Crack Growth ◽  
Pipeline Steel ◽  
Crack Tip ◽  
Crack Growth Resistance ◽  
Ductile Crack ◽  
Single Edge ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Ductile Crack Growth

In this study, the effects of residual stresses on the ductile crack growth resistance was investigated using single-edge-notched bending (SENB) and single-edge-notched tension (SENT) specimens as well as axisymmetric model. Weld residual stresses were introduced by the so-called eigenstrain method. The crack tip opening displacement (CTOD) and constraint parameter R were calculated for different specimens and residual stresses. Results show that the residual stresses slightly reduced the ductile crack growth resistance. However, crack tip constraint R elevated with the increase of residual stress.

Comparison of Fracture Toughness Curves Obtained by Single and Multi-Specimen Methodologies for a Pipe Having an Undermatched Girth Weld

2020 ◽  
Author(s):  
Diego F. B. Sarzosa ◽  
R. Savioli ◽  
C. Ruggieri ◽  
Alexandre Galiani Garmbis
Keyword(s):  
Carbon Steel ◽  
Crack Growth ◽  
Pipeline Steel ◽  
Crack Growth Resistance ◽  
Inconel 625 ◽  
External Diameter ◽  
Chromium Alloy ◽  
Nickel Chromium ◽  
Wide Range ◽  
Resistance Curves

Abstract Preventing catastrophic failure of engineering components is critical during the exploration and production of oil and gas resources from the offshore deep-water fields in Brazil. Pre-salt reserves are associated with high concentration of aggregated elements to hydrocarbons, particularly carbon dioxide (CO2) and hydrogen sulfide (H2S) which, in the presence of water can produce highly corrosive elements. One solution to this problem is to apply a metal liner made of corrosion-resistant alloy (CRA) internally to the carbon steel pipe. Such a bi-metallic configuration, commonly referred to as a lined pipe or clad pipe, consists essentially of a relatively thin CRA material pipe physically or metallurgically joined to the main carbon steel outer pipe. This experimental study presents an investigation of the ductile tearing properties for the girth weld of a typical C-Mn pipe internally clad with Inconel 625 CRA alloy using experimentally measured crack growth resistance curves. Here, the material of the external pipe is an API 5L Grade X65 pipeline steel and the inner clad layer is made of Inconel nickel-chromium alloy 625 (UNS N06625). The higher mechanical strength and superior resistance to a wide range of corrosive environments of unusual severity for this material derived from the combination of the nickel-chromium matrix with other microalloying elements. Testing of the pipeline girth welds employed clamped SE(T) specimens with a weld centerline notch to determine the crack growth resistance curves based upon the unloading compliance (UC) method using a single specimen method and the multi-specimen technique. The SE(T) specimens were extracted from a clad pipe having an external diameter of 220 mm and thickness of 23 mm. Further, the current experimental characterization provides toughness data that serve to evaluate the effectiveness of current procedures in determining accurate experimentally measured R-curves for this class of material.

Experimental Study of Fatigue Crack Overload Retardation in X80 Grade Steel

2008 ◽  
Author(s):  
Qingquan Duan ◽  
Hong Zhang ◽  
Feng Yan
Keyword(s):  
Fatigue Crack ◽  
Crack Growth ◽  
Oil And Gas ◽  
Prediction Models ◽  
Pipeline Steel ◽  
Compact Tension ◽  
X80 Pipeline Steel ◽  
Oil And Gas Pipelines ◽  
Crack Retardation ◽  
Grade Steel

The tests of fatigue crack overload retardation were performed to gain a some what deeper understanding of overload retardation. We present an experimental investigation of fatigue crack retardation behavior caused by intermediate single peak tensile overload under constant amplitude cyclic loading. The compact tension (CT) specimens of API grade X80 pipeline steel were used in fatigue test. The results show there was an instant crack extension during overloading for the tested overload ratios. As soon as the overload cycle was removed, instant delay in crack growth occurred. The results should be of interest for fracture mechanics prediction models on fatigue crack growth under variable amplitude loading and overloading effect for oil and gas pipelines.

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