Stepwise Cracking of Line Pipe Steels in Simulated Oilfield Environments

1982 ◽  
Author(s):  
Beverlee Gail Steinberg ◽  
Russell D. Kane
Keyword(s):  
Pipe Steels ◽  
Line Pipe

Niobium Microalloyed Line Pipe Steels: Technological Overview

2013 ◽  
Author(s):  
J. M. Gray ◽  
S. V. Subramanian
Keyword(s):  
Process Integration ◽  
Target Strength ◽  
Accelerated Cooling ◽  
Pipe Steels ◽  
Line Pipe ◽  
Steel Technology ◽  
Quantitative Understanding ◽  
Line Pipe Steel ◽  
Low Levels ◽  
Evolution Of Microstructure

A quantitative understanding of hierarchical evolution of microstructure is essential in order to design the base chemistry and optimize rolling schedules to obtain the morphological microstructure coupled with high density and dispersion of crystallographic high angle boundaries to achieve the target strength and fracture properties in higher grade line pipe steels, microalloyed with niobium. Product-process integration has been the key concept underlying the development of niobium microalloyed line pipe steel technology over the years. The development of HTP technology based on 0.1 wt % Nb and low interstitial was predicated by advances in process metallurgy to control interstitial elements to low levels (C <0.03wt% and N< 0.003wt%), sulfur to ultra-low levels (S<20ppm), as well as in product metallurgy based on advances in basic science aspects of thermo-mechanical rolling and phase transformation of pancaked austenite under accelerated cooling conditions, and toughness properties of heat affected zones in welding of niobium microalloyed line pipes. A historical perspective/technological overview of evolution of HTP for line pipe applications is the focus of this paper in order to highlight the key metallurgical concepts underlying Nb microalloying technology which have paved the way for successful development of higher grade line pipe steels over the years.

Improved Specifications Needed for Line Pipe Steels

1963 ◽  
Vol 15 (04) ◽  
pp. 370-374
Author(s):  
J.W. Squire
Keyword(s):  
Pipe Steels ◽  
Line Pipe

Influence of martensite-austenite (MA) on impact toughness of X80 line pipe steels

2016 ◽  
Vol 662 ◽  
pp. 481-491 ◽  
Author(s):  
Nazmul Huda ◽  
Abdelbaset R.H. Midawi ◽  
James Gianetto ◽  
Robert Lazor ◽  
Adrian P. Gerlich
Keyword(s):  
Impact Toughness ◽  
Pipe Steels ◽  
Line Pipe

A Pressure Reduction to Prevent a Time-Delayed Failure in a Damaged Pipeline

2020 ◽  
Author(s):  
Andrew Cosham ◽  
Brian N. Leis ◽  
Paul Roovers ◽  
Mures Zarèa ◽  
Valerie Linton
Keyword(s):  
Full Scale ◽  
The Other ◽  
Battelle Memorial Institute ◽  
Pressure Reduction ◽  
Pipe Steels ◽  
Percent Reduction ◽  
Lower Strength ◽  
Line Pipe ◽  
Delayed Failure ◽  
Strength And Toughness

Abstract A time-delayed failure due to stress-activated creep (cold-creep) is a failure that occurs under a constant load and with no growth due corrosion, fatigue or some other environmentally assisted time-dependent degradation mechanism. A time-delayed failure is prevented by reducing the pressure. ASME B31.4 and B31.8 recommend a 20 percent reduction, to 80 percent of the pressure at the time of damage or discovery. T/PM/P/11 Management Procedure for Inspection, assessment and repair of damaged (non-leaking) steel pipelines, an internal procedure used by National Grid, specifies a 15 percent reduction. The guidance in ASME B31.4 and B31.8, and in T/PM/P/11, is directly or indirectly based on the results of tests on the long term stability of defects conducted by the Battelle Memorial Institute and British Gas Corporation in the 1960s and 70s. The line pipe steels were Grades X52 or X60, and the full-size equivalent Charpy V-notch impact energy (where reported) did not exceed 35 J. The tests indicated that the threshold for a time-delayed failure was approximately 85–95% SAPF (straightaway-pressure-to-failure). The strength and toughness of line pipe steels has significantly increased over the decades due to developments in steel-making and processing. The question then is whether an empirical threshold based on tests on lower strength and lower toughness steels is applicable to higher strength and higher toughness steels. In the Tripartite Project, the Australian Pipelines and Gas Association (APGA), the European Pipeline Research Group (EPRG) and the Pipeline Research Council International (PRCI) collaborated in conducting full-scale six step-load-hold tests on higher strength and higher toughness steels. Companion papers present the other aspects of this multi-year project. An empirical threshold for a time-delayed failure is estimated using the results of the six step-load-hold tests. That estimate is also informed by the other published small and full-scale tests (on lower strength and lower toughness steels). The Ductile Flaw Growth Model is used to infer the effect of strength and toughness on the threshold for a time-delayed failure. A 15 percent pressure reduction, to 85 percent of the pressure at the time of damage (or of the maximum pressure that has occurred since the time of damage), is considered to be sufficient to prevent a time-delayed failure due to stress-activated creep in lower and higher toughness, in lower and higher strength, and in older and newer line pipe steels.

ULTRASONIC EVALUATION OF RESISTANCE TO HYDROGEN-INDUCED CRACKING OF LINE PIPE STEELS

1987 ◽  
pp. 359-365
Author(s):  
J.C. ALBERT ◽  
O. CASSIER ◽  
H. MARGOT-MARETTE ◽  
G. BARDOU ◽  
P. VIRLOUVET
Keyword(s):  
Pipe Steels ◽  
Line Pipe ◽  
Ultrasonic Evaluation ◽  
Hydrogen Induced Cracking

Hydrogen Compatibility and Suitability of (Ni)-Cr-Mo High-Strength Low-Alloy Seamless Line Pipe Steels for Pressure Vessels for Hydrogen Storage

2018 ◽  
Author(s):  
Akihide Nagao ◽  
Nobuyuki Ishikawa ◽  
Toshio Takano
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Strength ◽  
Pressure Vessels ◽  
Hydrogen Gas ◽  
Low Alloy Steels ◽  
Pipe Steels ◽  
Line Pipe ◽  
Alloy Steels ◽  
Pressure Hydrogen

Cr-Mo and Ni-Cr-Mo high-strength low-alloy steels are candidate materials for the storage of high-pressure hydrogen gas. Forging materials of these steels have been used for such an environment, while there has been a strong demand for a higher performance material with high resistance to hydrogen embrittlement at lower cost. Thus, mechanical properties of Cr-Mo and Ni-Cr-Mo steels made of quenched and tempered seamless pipes in high-pressure hydrogen gas up to 105 MPa were examined in this study. The mechanical properties were deteriorated in the presence of hydrogen that appeared in reduction in local elongation, decrease in fracture toughness and accelerated fatigue-crack growth rate, although the presence of hydrogen did not affect yield and ultimate tensile strengths and made little difference to the fatigue endurance limit. It is proposed that pressure vessels for the storage of gaseous hydrogen made of these seamless line pipe steels can be designed.

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