Mass Production and Installation of X100 Linepipe for Strain-Based Design Application

Author(s):  
Nobuyuki Ishikawa ◽  
Mitsuhiro Okatsu ◽  
Shigeru Endo ◽  
Joe Kondo ◽  
Joe Zhou ◽  
...  

Continuous efforts have been made for the realization of strain-based design pipeline using high grade linepipe materials. Two demonstrative constructions of the pipelines using X100 linepipe proved sufficient materials properties for strain-based design and high quality field welding with good productivity. In order to verify further applicability of high strain X100 linepipe for long distance transmission, large scale installation of X100 pipeline was accomplished. Mass production of X100 linepipe of about 2,000 metric tons with the size of 42″OD and 14.3mm wall thick was successfully conducted by applying recent developed TMCP process including accelerated cooling and online heat treatment process and UOE pipe forming. Field girth welding was safely completed by the dual tandem pulsed GMAW, and sufficient girth weld properties were demonstrated. This paper will describe material development and mass production results of X100 linepipe for strain-based design which specifying longitudinal tensile properties such as Y/T ratio and uniform elongation. In order to securely specify the shape of stress-strain curve without Luders elongation, material parameter “stress ratio” was introduced for the material specification for compressive strain capacity. Stringent base metal requirements were imposed for base metal material properties in this project. One of the most challenging aspects in developing high strain linepipe is to balance uniform elongation and Charpy absorbed energy. Dual phase microstructure is essential to improve strain capacity, but this may lead to lower Charpy absorbed energy. Therefore, precise control of microstructure by controlling plate manufacturing parameter was required. In addition, on-line heating process subsequently after accelerated cooling enabled increase of Charpy energy without deteriorating uniform elongation. Girth weld properties were closely evaluated using the X100 pipe in as UOE condition and after external coating. All the material properties of base metal and girth weldment of the X100 linepipes used for this project fulfill the stringent requirement for strain-based design consideration to prevent buckling and weld fracture.

Author(s):  
Hisakazu Tajika ◽  
Satoshi Igi ◽  
Takahiro Sakimoto ◽  
Shigeru Endo ◽  
Seishi Tsuyama ◽  
...  

This paper presents the results of experimental studies focused on the strain capacity of X80 linepipe. A full-scale bending tests of X80 grade, 48″ high-strain linepipes pressurized to 60% SMYS were conducted to investigate the compressive strain limit and tensile strain limit. The tensile properties Y/T ratios and uniform elongation of the pipes had variety. Three of four pipes are high strain pipes and these Y/T ratios are intentionally low with manufacturing method. One of these high-strain pipe was girth welded in its longitudinal center to investigate the effect of girth weld to strain capacity. The other was set as a conventional pipe that have higher Y/T ratio to make comparative study. The compressive strain limit focused on the critical strain at the formation of local buckling on the compression side of bending. After pipe reaches its endurable maximum moment, one large developed wrinkle and some small wrinkles on the pipe surface during bending deformation were captured relatively well from observation and strain distribution measurement. The tensile strain limit is discussed from the viewpoint of competition of two fracture phenomena: ductile crack initiation/propagation from an artificial notch at the HAZ of the girth weld, and strain concentration and rupture in the base material at the tension (opposite) side of the local buckling position.


Author(s):  
Ryuji Muraoka ◽  
Joe Kondo ◽  
Lingkang Ji ◽  
Hongyuan Chen ◽  
Yaorong Feng ◽  
...  

In order to achieve safety and reliability of long-distance gas transmission pipeline installed in seismic region while obtaining economical benefit by reducing material and construction cost, it is essential to apply the high-strength linepipes with sufficient strain capacity against buckling and weld fracture by seismic ground movement. At the same time, it is quite important to develop appropriate material requirement for strain capacity depending on the pipe dimension and strain demand of the region where the pipeline is installed. Grade X80 heavy gauge linepipes with excellent deformability were mass produced by applying advanced plate manufacturing technologies. These linepipes exhibit low Y/T and high uniform elongation in the longitudinal direction even after pipe coating. Strain capacity of the pipe against bending deformation with internal pressure was verified by conducting full scale pipe bending testing. In this paper, production results of high strain X80 linepipes for the application in long-distance pipelines in seismic region and full scale pipe bending and hydraulic burst test results were introduced.


Author(s):  
Hongyuan Chen ◽  
Lingkang Ji ◽  
Shaotao Gong ◽  
Huilin Gao

The use of strain based design in pipeline technology has been widely discussed during the last decade for pipelines in harsh environment. In such cases pipelines should be designed based on strain criterion. Strain based design poses a number of challenges, particularly on pipe size and material properties. This paper presents preliminary studies on prediction of buckling strain and buckling mode for X80 high-strain line pipe by finite element methods based on full-scale test. The effects of several parameters such as internal pressure, material properties pipe size and geometric imperfection, were investigated to predict the critical strain for 48″ diameter line pipe under compression and pure bending with 12MPa internal pressure. Material parameters of a specification for high strain line pipe were analyzed to promote its application in the 2nd West-East pipeline of China National Petroleum Corporation.


Author(s):  
Hisakazu Tajika ◽  
Takahiro Sakimoto ◽  
Tsunehisa Handa ◽  
Rinsei Ikeda ◽  
Joe Kondo

Recently high grade pipeline project have been planned in hostile environment like landslide in mountain area, liquefaction in reclaimed land or the frost heave in Polar Regions. Geohazards bring large scale ground deformation and effect on the varied pipeline to cause large deformation. Therefore, strain capacity is important for the pipeline and strain based design is also needed to keep gas transportation project in safe. High grade steel pipe for linepipe tends to have higher yield to tensile (Y/T) ratio and it has been investigated that the lower Y/T ratio of the material improves strain capacity in buckling and tensile limit state. In onshore pipeline project, pipe usually transported in 12 or 18m each and jointed in the field. Girth weld (GW) is indispensable so strength matching of girth weld towards pipe body is important. In this study strain capacity of Grade X70 high strain pipes with size of 36″ OD and 23mm WT was investigated with two types of experiments, which are full scale pipe bending tests and curved wide plate tests. The length of the specimen of full scale bending tests were approximately 8m and girth weld was made in the middle of joint length. A fixed internal pressure was applied during the bending test. Actual pipe situation in work was simulated and both circumferential and longitudinal stress occurred in this test. Test pipes were cut and welded, GTAW in first two layer and then finished by GMAW. In one pipe, YS-TS over-matching girth weld (OVM) joint was prepared considering the pipe body grade. For the other pipe, intentionally under-matching girth weld (UDM) joint was prepared. After the girth welding, elliptical EDM notch were installed in the GW HAZ as simulated weld defect. In both pipe bending tests, the buckling occurred in the pipe body at approximately 300mm apart from the GW and after that, deformation concentrated to buckling wrinkle. Test pipe breaking locations were different in the two tests. In OVM, tensile rupture occurred in pipe body on the backside of buckling wrinkle. In UDM, tensile rupture occurred from notch in the HAZ. In CWP test, breaking location was the HAZ notch. There were significant differences in CTOD growth in HAZ notch in these tests.


2012 ◽  
Vol 735 ◽  
pp. 271-277 ◽  
Author(s):  
Tomoyuki Kudo ◽  
Akira Goto ◽  
Kazuya Saito

Blow forming accompanied with superplasticity makes possible the forming of complex parts, which cannot be formed by cold press forming. The conventional superplastic AA5083 alloy ‘ALNOVI-1’ developed by the Furukawa-Sky Aluminum Corp. shows high superplasticity because of its fine grain and is widely used for blow forming. However, for mass production of components, an Al-Mg alloy with finer-sized grains is needed. In this research, the newly developed high Mn version of the Al-Mg alloy ‘ALNOVI-U’ is used, and this material possesses grains finer than those of the conventional AA5083 alloy. The effects of finer grain size on the blow formability at high strain rates over 10-2/s and the properties of the resulting moldings were studied.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Kee-nam Song ◽  
Sang-hoon Lee

Mechanical properties in a weld zone are different from those in the base material because of different microstructures. A spacer grid in PWR fuel is a structural component with an interconnected and welded array of slotted grid straps. Previous research on the strength analyses of the spacer grid was performed using base material properties owing to a lack of mechanical properties in the weld zone. In this study, based on the mechanical properties in the weld zone of the spacer grid recently obtained by an instrumented indentation technique, the strength analyses considering the mechanical properties in the weld zone were performed, and the analysis results were compared with the previous research.


1992 ◽  
Vol 20 (4) ◽  
pp. 248 ◽  
Author(s):  
D Petersen ◽  
IS Hwang ◽  
MM Morra ◽  
RG Ballinger ◽  
H Nakajima ◽  
...  

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