Shear Fracture Arrestability of Controlled Rolled Steel X70 Line Pipe by Full-Scale Burst Test

1984 ◽  
Vol 106 (1) ◽  
pp. 55-62 ◽  
Author(s):  
E. Sugie ◽  
H. Kaji ◽  
T. Taira ◽  
M. Ohashi ◽  
Y. Sumitomo
Keyword(s):  
Shear Fracture ◽  
High Strength ◽  
Full Scale ◽  
Research Committee ◽  
Line Pipe ◽  
Iron And Steel ◽  
Propagation Behavior ◽  
Velocity Relationship ◽  
On Line ◽  
Propagating Shear

The High Strength Line Pipe Research Committee organized by the Iron and Steel Institute of Japan has conducted five full-scale burst tests on line pipe of 48 in. o.d. × 0.720 in. w.t. (wall thickness) and grade X70 under pressure of 80 percent SMYS with air: 1) to study the influence of separation on the arrestability of shear fracture, and 2) to obtain the material criterion for arresting the propagating shear fracture. Test pipes of Charpy V notch energy from 80 to 290J with different amount of separation, were produced from both controlled rolled steels and quenched and tempered steels. These research projects clarified that the separation of material itself did not influence the crack propagation behavior and its arrestability. Furthermore, the material criterion for arresting the shear fracture was analyzed by the pressure-velocity relationship counterbalancing the crack velocity curve and gas decompression curve.

Notch Ductilities of Rich Natural Gas Transmission Line Pipes for Arresting Propagating Shear Fracture

1987 ◽  
Vol 109 (1) ◽  
pp. 2-8 ◽  
Author(s):  
E. Sugie ◽  
M. Matsuoka ◽  
T. Akiyama ◽  
K. Tanaka ◽  
Y. Kawaguchi
Keyword(s):  
Natural Gas ◽  
Crack Velocity ◽  
Shear Fracture ◽  
High Strength ◽  
Velocity Curve ◽  
Research Committee ◽  
Velocity Change ◽  
Charpy Test ◽  
Line Pipe ◽  
Propagating Shear

High Strength Line Pipe Research Committee organized by The Iron and Steel Institute of Japan carried out two full-scale burst tests on X70 line pipes, 48 in. o.d. × 0.720 in. w.t., with rich natural gas as the pressurizing gas. A theoretical investigation which gives the crack velocity change in terms of the crack velocity curve and the gas decompression velocity curve is presented, and the theoretical predictions and the experimental results are in good agreement. The developed method can predict the required notch ductilities obtained from Charpy test and DWTT in order to arrest a propagating shear fracture according to the type of gas, design stress and acceptable fracture length in the pipeline.

Fracture Resistance in Line Pipe

1965 ◽  
Vol 87 (3) ◽  
pp. 265-278 ◽  
Author(s):  
G. M. McClure ◽  
A. R. Duffy ◽  
R. J. Eiber
Keyword(s):  
Fracture Behavior ◽  
Large Diameter ◽  
Full Scale ◽  
Laboratory Studies ◽  
Research Committee ◽  
Line Pipe ◽  
Diameter Pipe ◽  
On Line ◽  
Fracture Tests ◽  
Scale Behavior

The program of research on line pipe under the sponsorship of the A.G.A. Pipeline Research Committee is a comprehensive effort to investigate the important properties of pipe used in gas transmission. Several different phases are involved in this project, ranging from fundamental laboratory studies to fracture-behavior experiments on large-diameter pipe. This paper discusses the full-scale experimental parts of the program in which the fracture toughness of line pipe is being studied. Some of the factors that influence full-scale fracture behavior are discussed—material properties, fracture speed, temperature, wall thickness, nominal stress level, and type of backfill. Laboratory fracture tests that are being run and correlated with full-scale behavior are also described.

Pipe Deformation During a Running Shear Fracture in Line Pipe

1974 ◽  
Vol 96 (4) ◽  
pp. 309-317 ◽  
Author(s):  
K. D. Ives ◽  
A. K. Shoemaker ◽  
R. F. McCartney
Keyword(s):  
Circumferential Strain ◽  
Shear Fracture ◽  
Large Diameter ◽  
Crack Tip ◽  
Local Pressure ◽  
Pipe Length ◽  
Line Pipe ◽  
Iron And Steel ◽  
Pressure Transducers ◽  
Propagating Shear

Under sponsorship of the American Iron and Steel Institute, U. S. Steel Research has been conducting full-scale burst tests of large-diameter submerged-arc-welded line pipe to determine the toughness required to arrest running shear fractures for different design conditions. As part of that program, the pipe were instrumented with crack detectors, strain gages, and pressure transducers to determine the crack velocities and the actual pipe deformation and strain fields associated with the shear fracture propagating along the top of the pipe. This paper summarizes the test data that document the manner in which the pipe deforms during this type of crack propagation. The data show that for a propagating shear fracture, each of four different locations along the pipe length (relative to the crack tip) has a distinctive type of pipe deformation. For a location many pipe diameters ahead of the crack tip, the circumferential strain first decreases because of flexural waves associated with the initiation process and then continues to decrease in proportion to the local gas decompression; however, the longitudinal strain continuously increases because of a longitudinal “tongue” of tensile straining on the top of the pipe caused by pressure-induced opening of the flaps of the pipe on both sides of the fracture behind the crack tip. At a distance about two diameters ahead of the crack tip, the pipe cross section becomes oval, and in the presence of this deformation the strain field is no longer determined by the local pressure; in fact, the circumferential strain is near zero at a distance two diameters ahead of the crack. The oval pipe shape ahead of the crack tip is caused by the venting of the gas behind the crack tip which creates a downward reactive force on the bottom portion of the pipe. Opening at the crack tip is the result of tensile straining caused by circumferential and radial displacement of the flaps behind the crack tip. Thus it is believed that the action of the pipe-wall flaps behind the crack tip provides the primary force driving the crack down the top of the pipe.

Research and Development of Deep-Sea Pipeline Steel

2010 ◽  
Vol 152-153 ◽  
pp. 1492-1498
Author(s):  
Jin Qiao Xu ◽  
Bin Guo ◽  
Lin Zheng ◽  
Yin Hua Li ◽  
Le Yu
Keyword(s):  
Low Temperature ◽  
Deep Sea ◽  
Pipeline Steel ◽  
High Strength ◽  
Steel Company ◽  
Line Pipe ◽  
Iron And Steel ◽  
Company Group ◽  
Pipeline Project ◽  
Low Temperature Toughness

This paper provides a detailed description of deep-sea pipeline steel developed at Wuhan Iron and Steel Company(Group), WISCO for short. The thickness of the trial produced plates is 28mm. The chemical composition of low C-high Mn-Nb-Ti with proper content of other alloys and thermo-mechanical controlled process were applied. The results show that the deep-sea pipeline steel developed at Wuhan Iron and Steel Company has a good match of high strength, low temperature toughness and excellent deformability with fine uniform microstructure. The LSAW line pipe manufactured by JCOE method has high strength, good low temperature toughness and low yield ratio which comprehensively meet the requirements of the South China Sea Liwan pipeline project.

Displacement Consideration for a Ductile Propagating Fracture in Line Pipe

1974 ◽  
Vol 96 (4) ◽  
pp. 318-322 ◽  
Author(s):  
A. K. Shoemaker ◽  
R. F. McCartney
Keyword(s):  
Driving Force ◽  
Driving Forces ◽  
Pipe Wall ◽  
Shear Fracture ◽  
Crack Tip ◽  
Complex Problem ◽  
Empirical Correlations ◽  
Line Pipe ◽  
Velocity Of Propagation ◽  
Propagating Shear

To date, the technically complex problem of arriving at an analysis for a running shear fracture in a gas-transmission line pipe has been primarily viewed by investigators in terms of an energy balance that involves empirical correlations of data. In contrast, in the present paper, the problem is reviewed in terms of the forces, masses, and time involved in the fracturing event and the resultant accelerations, velocities, and displacements with respect to (1) the forces driving the crack, (2) the pipe-wall ductility resisting the driving forces, and (3) the manner in which the crack arrests. Special attention is given to the effects of backfill on these events. On the bases of the data available, it is proposed that the displacements developed by the driving force are the result of the acceleration developed by the pressure acting on the flaps behind the crack. The driving force developed by the flaps results in forces which open the crack. For a constant velocity of propagation, the time for this flap displacement corresponds to the time for the pipe-wall thinning at the crack tip, which is controlled by the pipe-wall ductility. Thus, pipe-wall ductility can limit the speed of the crack. At a low crack speed, sufficient radial displacement of the flaps behind the crack occurs to cause the crack to turn in a helical path and arrest. Finally, the backfill significantly decreases the driving force and thus reduces the pipe-wall ductility necessary for arrest. Therefore, considerations of the displacements which occur during a propagating shear fracture indicate that the time and forces required for thinning the material at the crack tip, which is essentially governed by the ductility of the pipe wall, limit the speed of the crack.

scholarly journals Power Cooling

2016 ◽  
Vol 854 ◽  
pp. 225-230
Author(s):  
Erich Opitz ◽  
Alois Seilinger ◽  
Lukas Pichler ◽  
Olaf Silbermann ◽  
Axel Rimnac
Keyword(s):  
Cooling System ◽  
Hsla Steel ◽  
High Strength ◽  
Pipe Material ◽  
Line Pipe ◽  
Iron And Steel ◽  
Hot Strip ◽  
Finishing Mill ◽  
Steel Grades ◽  
Hot Strip Mills

During the last years international steel producers have been following a market trend to develop and produce new steel grades with higher strength and larger thickness. When attempting to improve the metallurgical properties in the cooling section, the existing cooling equipment in hot strip mills often reaches its limit. Primetals Technologies offers its Power Cooling solution to upgrade existing cooling lines as well as for new hot strip mills. With this type of equipment highest cooling rates can be achieved and therefore steel producers are capable of producing new steel grades with higher strength at lower costs. A new power cooling system was installed immediately behind the finishing mill gauge house at Wuhan Iron and Steel Company’s (WISCO) HSM No. 2 in Wuhan, China. The Power Cooling system widens the product range and gives WISCO the capability to produce high-strength steel grades (AHSS) with strength levels of more than 1,000 MPa, e.g. HSLA steel or as-hot-rolled multi-phase steel. Due to the extremely wide control range of the flow rate, the installation allows for maximum metallurgical flexibility. On the other hand, the new equipment allows for the most economic production of line-pipe material like API X80 in a thickness range up to 25.4 mm (1 inch).

Effect of Separation on Ductile Crack Propagation Behavior During Drop Weight Tear Test

2010 ◽  
Author(s):  
Takuya Hara ◽  
Taishi Fujishiro
Keyword(s):  
Crack Propagation ◽  
Ductile Fracture ◽  
Fracture Resistance ◽  
High Strength ◽  
Opening Angle ◽  
Ductile Crack ◽  
Line Pipe ◽  
Propagation Behavior ◽  
Drop Weight ◽  
Drop Weight Tear Test

The demand for natural gas using LNG and pipelines to supply the world gas markets is increasing. The use of high-strength line pipe provides a reduction in the cost of gas transmission pipelines by enabling high-pressure transmission of large volumes of gas. Under the large demand of high-strength line pipe, crack arrestability of running ductile fracture behavior is one of the most important properties. The CVN (Charpy V-notched) test and the DWTT (Drop Weight Tear Test) are major test methods to evaluate the crack arrestability of running ductile fractures. Separation, which is defined as a fracture parallel to the rolling plane, can be characteristic of the fracture in both full-scale burst tests and DWTTs. It is reported that separations deteriorate the crack arrestability of running ductile fracture, and also that small amounts of separation do not affect the running ductile fracture resistance. This paper describes the effect of separation on ductile propagation behavior. We utilized a high-speed camera to investigate the CTOA (Crack Tip Opening Angle) during the DWTT. We show that some separations deteriorate ductile crack propagation resistance and that some separations do not affect the running ductile fracture resistance.

Notch Ductility Requirements of Line Pipes for Arresting Propagating Shear Fracture

1987 ◽  
Vol 109 (4) ◽  
pp. 428-434 ◽  
Author(s):  
E. Sugie ◽  
M. Matsuoka ◽  
T. Akiyama ◽  
K. Tanaka ◽  
Y. Kawaguchi
Keyword(s):  
Natural Gas ◽  
Shear Fracture ◽  
Full Scale ◽  
Experimental Results ◽  
Fracture Length ◽  
Theoretical Investigations ◽  
The Rich ◽  
Propagating Shear ◽  
Design Stress ◽  
Very High

Full-scale burst tests were carried out on X70 line pipes, 48 in. o. d. × 0.720 in. w. t., with air and rich and natural gas as the pressurizing gases. The experimental results indicated that very high notch ductilities of pipes are required for arresting propagating shear fracture especially in the case of the rich natural gas. From theoretical investigations a method was developed which enabled the prediction of the required notch ductilities of line pipes with regard to the type of gas, design stress and acceptable fracture length.

scholarly journals Study on the Propagating Shear Fracture in High Strength Line Pipes by Partial-gas Burst Test.

2001 ◽  
Vol 41 (7) ◽  
pp. 788-794 ◽  
Author(s):  
Hiroyuki Makino ◽  
Izumi Takeuchi ◽  
Masatoshi Tsukamoto ◽  
Yoshiaki Kawaguchi
Keyword(s):  
Shear Fracture ◽  
High Strength ◽  
Burst Test ◽  
Propagating Shear
Sign in / Sign up

Export Citation Format

Share Document