Full Gas Burst Test for HFW Linepipe at Low Temperature

2014 ◽  
Author(s):  
Satoshi Igi ◽  
Satoru Yabumoto ◽  
Masaki Mitsuya ◽  
Yuya Sumikura ◽  
Mikihiro Takeuchi
Keyword(s):  
Residual Stress ◽  
Low Temperature ◽  
Fracture Behavior ◽  
Weld Seam ◽  
Base Material ◽  
Welding Process ◽  
Manufacturing Method ◽  
Burst Test ◽  
Drop Weight Tear Test ◽  
The Difference

A full gas burst test at low temperature below −40°C was performed using a high frequency welded (HFW) linepipe with high-quality weld seam, “MightySeam®,” [1–4] in order to verify the applicability of the Drop Weight Tear Test (DWTT). Residual stress exists in the pipe body of HFW linepipe because the manufacturing method includes a sizing process. Therefore, it is necessary to clarify the difference between the arrestability in the DWTT without residual stress in the specimen and that in the full gas burst test with residual stress in the pipe body. The full gas burst test is performed using a test pipe specimen in which a notch is introduced into the base material by an explosive cutter. In addition, a test pipe specimen with a notch introduced into the weld seam was used in this study because the developed HFW linepipe, “MightySeam®,” has excellent low-temperature toughness as a result of control of the morphology and distribution of oxides generated in the welding process by temperature and deformation distribution control. The Charpy transition temperature of “Mighty Seam®” was much lower than −45 °C. Ductile cracks were initiated from the initial explosive notch, and these cracks were arrested after ductile crack propagation of about 1 m in base material on both sides. The fracture behavior was similar in appearance in the DWTT without residual stress and the full gas burst test with residual stress.

Fracture Behavior in West Jefferson Test Under Low-Temperature Condition for X65 Steel Pipe With High Charpy Energy: Current Activities in HLP Committee, Japan, Report 1

2016 ◽  
Author(s):  
Toshihiko Amano ◽  
Satoshi Igi ◽  
Takahiro Sakimoto ◽  
Takehiro Inoue ◽  
Shuji Aihara
Keyword(s):  
Transition Temperature ◽  
Low Temperature ◽  
Brittle Fracture ◽  
Pressure Vessel ◽  
Fracture Behavior ◽  
Line Pipe ◽  
Burst Test ◽  
Pipe Burst ◽  
Test Vessel ◽  
Fracture Appearance

This paper describes the results of pressure vessel fracture test which called West Jefferson and/or partial gas burst testing using Grade API X65 linepipe steel with high Charpy energy that exhibits inverse facture in the Drop Weight Tear Test (DWTT). A series of pressure vessel fracture tests which is as part of an ongoing effort by the High-strength Line Pipe committee (HLP) of the Iron and Steel Institute of Japan (ISIJ) was carried out at low temperature in order to investigate brittle-to-ductile transition behavior and to compare to DWTT fracture behavior. Two different materials on Fracture Appearance Transition Temperature (FATT) property were used in these tests. One is −60 degree C and the other is −25 to −30 degree C which is defined as 85 % shear area fraction (SA) in the standard pressed notch DWTT (PN-DWTT). The dimensions of the test pipes were 24inches (609.6 mm) in outside diameter (OD), 19.1 mm in wall thickness (WT). In each test, the test pipe is cooled by using liquid nitrogen in the cooling baths. Two cooling baths are set up separately on the two sides of the test vessel, making it possible to obtain fracture behaviors under two different test temperatures in one burst test. The test vessel was also instrumented with pressure transducers, thermocouples and timing wires to obtain the pressure at the fracture onset, temperature and crack propagation velocity, respectively. Some informative observations to discuss appropriate evaluation method for material resistance to brittle facture propagation for high toughness linepipe materials are obtained in the test. When the pipe burst test temperatures are higher than the PN-DWTT transition temperature, ductile cracks were initiated from the initial notch and propagated with short distance in ductile manner. When the pipe burst test temperatures were lower than the PN-DWTT transition temperature, brittle cracks were initiated from the initial notch and propagated through cooling bath. However, the initiated ductile crack at lower than the transition temperature was not changed to brittle manner. This means inverse facture occurred in the PN-DWTT is a particular problem caused by the API DWTT testing method. Furthermore, results for the pipes tested indicated that inverse facture occurred in PN-DWTT at the temperature above the 85 % FATT may not affect the arrestability against the brittle fracture propagation and it is closely related with the location of brittle fracture initiation origin in the fracture appearance of PN-DWTT.

scholarly journals A Study on the Friction Stir Welding Experiment and Simulation of the Fillet Joint of Extruded Aluminum Material of Electric Vehicle Frame

2020 ◽  
Vol 10 (24) ◽  
pp. 9103
Author(s):  
Hwanjin Kim ◽  
Kwangjin Lee ◽  
Jaewoong Kim ◽  
Changyeon Lee ◽  
Yoonchul Jung ◽  
...  
Keyword(s):  
Residual Stress ◽  
Friction Stir Welding ◽  
Electric Vehicle ◽  
Manufacturing Process ◽  
Base Material ◽  
Welding Process ◽  
Inert Gas ◽  
Measured Temperature ◽  
Friction Stir ◽  
Fillet Joint

In the existing automobile manufacturing process, metal inert gas (MIG) and tungsten inert gas (TIG) welding are mainly used. These welding methods are fusion welding, and the heat input in the welding area is very high. Therefore, the deformation of the base material is large, and the residual stress in the vicinity of the welded area is high, resulting in the problem of reduced mechanical strength. In this study, friction stir welding (FSW) was applied to the welding process of the structure constituting the battery frame of a newly developing electric vehicle to compensate for this problem. The welded part is the fillet joint of the side frame and the bottom frame, and experiments and numerical analysis were performed on the welding deformation and residual stress of the full frame structure. A specially manufactured angle head was used for friction stir welding of the fillet joint of extruded type aluminum, not the existing solid type. The optimum process was derived through experiments, and the temperature of the welding center was derived through test correlation between the value of measured temperature and the finite element model. The final deformation result was verified by comparing it with the measured value using a dial indicator. It is expected that the proposed thermal elasto-plastic analysis method will reduce the testing period and the cost of the manufacturing process and increase productivity.

Metallugical Design and Performance of ERW Linepipe With High-Quality Weld Seam Suitable for Extra-Low-Temperature Services

2012 ◽  
Author(s):  
Shunsuke Toyoda ◽  
Sota Goto ◽  
Takatoshi Okabe ◽  
Hideto Kimura ◽  
Satoshi Igi ◽  
...  
Keyword(s):  
Low Temperature ◽  
Weld Seam ◽  
Stress Triaxiality ◽  
Welding Process ◽  
Strain Curve ◽  
Interface Debonding ◽  
Cleavage Crack ◽  
Maximum Point ◽  
High Quality ◽  
The Matrix

To clarify the effect of inclusions on the Charpy impact properties, the 2 mm V-notched Charpy properties of X60 – X80-grades steel were numerically simulated using the finite element method code ABAQUS. The yield strength and the tensile strength of the steel were 562 MPa and 644 MPa, respectively. The striker’s velocity and the temperature dependency of the stress-strain curve were taken into account. To estimate the effect of nonmetallic inclusions, a 200 μm long virtual inclusion with a 1 μm edge radius was situated at the maximum point of the stress triaxiality. Four types of micro crack initiation were determined: (a) ductile void generation in the matrix, (b) cleavage crack generation in the matrix, (c) void generation by inclusion fracture and (d) void generation by matrix-inclusion interface debonding. Without inclusions, a ductile micro void was generated when the striker stroke was 3.3 mm, independent of the temperature. With inclusions, an inclusion fracture occurred when the striker stroke was 0.6 mm at room temperature. The striker stroke decreased as the temperature decreased. Based on the above numerical estimation results, electric resistance welded (ERW) Linepipe with high-quality weld seam MightySeam® has been developed. Controlling the morphology and distribution of oxides generated during the welding process by means of temperature and deformation distribution control is the key factor for improving the low-temperature toughness. The Charpy transition temperature of the developed ERW pipe was much lower than −45°C. Based on the low-temperature hydrostatic burst test with a notched weld seam at −20 °C, the MightySeam® weld provides a fracture performance that is the same as UOE Double Submerged Arc Welded pipe. The pipe has been used in actual, highly demanding, severe environments.

scholarly journals Strength and Reliability Estimation of a Low Temperature Co-Fired Ceramic (LTCC) With and Without Metallic Features

2011 ◽  
Vol 2011 (1) ◽  
pp. 000753-000759
Author(s):  
Rajan Tandon ◽  
Clay S. Newton
Keyword(s):  
Experimental Data ◽  
Residual Stress ◽  
Stress State ◽  
Low Temperature ◽  
Reliability Assessment ◽  
Base Material ◽  
Reliability Estimation ◽  
Critical Crack ◽  
Design Life ◽  
Advanced Packaging

The use of Low Temperature Co-Fired Ceramics (LTCC) is a very attractive material option for advanced packaging. For applications, a variety of features are printed in the base material: thermal and electrical vias, resistors, solder pads to name a few. Most of these features have materials that are thermally and elastically mismatched from the LTCC, producing a localized residual stress. These stresses impact the strength and reliability of the LTCC package. Here we present results and analysis for the strength and reliability assessment of an LTCC (Dupont™ 951) with and without Au vias. The reliability of the ceramic material is assessed from the perspective of its susceptibility to sub-critical crack growth (SCG). Metallic vias can significantly lower the strength of the LTCC, however, their presence does not change the measured susceptibility of the material to SCG. Using our experimental data, and empirical descriptions of SCG laws, safe design life for LTCC packages under a particular stress state is estimated.

Microstructure Transformation and Mechanical Properties of X80 Large Diameter Thick Wall Induction Heating Bend for Low Temperature Service

2020 ◽  
Author(s):  
Yu Liu ◽  
Zongbin You ◽  
Lijun Yan
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Weld Metal ◽  
Acicular Ferrite ◽  
Base Material ◽  
Welding Process ◽  
Seam Weld ◽  
Bent Pipe ◽  
Low Temperature Toughness ◽  
Submerged Arc

Abstract For the requirement of pipeline station construction project, Grade X80 Longitudinally Submerged Arc Welded (LSAW) induction bend pipe 1422 mm in diameter and wall thickness greater than 25 mm have been developed for pipeline station service applications at −45 °C. The mother pipe of the bends was welded by Ni-Cr-Cu-Mo-Nb-V micro-alloyed Thermo Mechanical Control Process (TMCP) steel plates. After the heat cycle of the bent pipe manufacturing, the microstructure of the base material of the bent pipe consisted of lath bainite ferrite (LBF) and granular bainite (GB). Therefore, it can obtain high strength and excellent low temperature toughness, which can meet the requirements of the project. On the other hand, the welding of the longitudinal seam-welds of the bend mother pipe uses a typical multi-wire two-pass submerged arc welding (SAW) process, which has a large amount of welding heat input. This results in a coarse columnar weld structure with a large amount of fine acicular ferrite so that the seam weld still has a good low temperature impact toughness. However, after the thermal cycling of the bend, the acicular ferrite in the microstructure of the weld metal was greatly reduced, and the grain size was unevenly distributed, which caused the low temperature toughness of the weld metal to deteriorate significantly. In order to solve this problem, the Gleeble3500 thermal simulation test machine was used to test the phase transition critical point Ac3 of the base material and the seam weld metal of the mother pipe. In order to optimize the induction bend process parameters, the influence of heating temperature, cooling rate and tempering temperature on microstructure and mechanical properties were examined. In addition, on the basis of the existing welding process, the welding wire and flux for pipe-making seam-welding were improved, and the pipe-making welding process of the bent mother pipe was improved.

Influence of Low-Temperature Freezing Treatment on Micro-Area Hardness and Residual Stress of SiCp/Al Composites

2012 ◽  
Vol 497 ◽  
pp. 344-349
Author(s):  
X.L. Yu ◽  
S.T. Huang ◽  
W.Z. Zhao ◽  
L. Zhou
Keyword(s):  
Residual Stress ◽  
Low Temperature ◽  
Matrix Phase ◽  
Residual Tensile Stress ◽  
Two Phase ◽  
Hardness Tester ◽  
Sic Particles ◽  
Freezing Treatment ◽  
The Difference ◽  
Al Matrix

In order to study the effect of freezing treatment on the mechanical properties of SiCp/Al composites, SiCp/Al composites were froze by liquid nitrogen for different time. The micro-area hardness, two-phase residual stress and interface combination status of were analyzed with micro hardness tester, x-ray diffractometer and SEM before and after freezing treatment. The results show that the hardness of Al matrix after freezing is higher than that of before freezing, while the hardness of SiC particles does not show much change. Low-temperature freezing makes the residual compressive stress of matrix phase and the residual tensile stress of reinforcing phase reduce. With the increasing of freezing time, the difference value between the measured residual stress and the primary residual stress of Al matrix and SiC particles both turn out to be greater. Freezing can not destroy the interface combination status between the matrix phase and the reinforcing phase.

Impact of Welding Parameters on Weld Seam Properties of Seamless X80 Linepipe Steel Grade

2014 ◽  
Author(s):  
Claas Bruns ◽  
Jörg Wiebe ◽  
Dorothee Niklasch ◽  
Denise Mahn ◽  
Tanja Schmidt
Keyword(s):  
Weld Seam ◽  
Mechanical Test ◽  
Base Material ◽  
Welding Process ◽  
Charpy Impact ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Test Results ◽  
Linepipe Steel

The challenging exploration conditions appearing in ultra deep offshore projects promoted the development of high strength linepipe steel grades with yield strength of 80 ksi and higher in recent years. With increasing strength more attention has to be paid to welding procedures to realise the required mechanical properties of the weld seam. The combination of demanding toughness requirements at low temperatures and adequate corrosion resistance of welded joints is a key for complex deep offshore riser and linepipe applications. The welding process was optimised by Vallourec with respect to heat input and preheating temperature for joining seamless quenched and tempered pipes in grade X80. A root welding strategy has been developed particularly with regards to sour service applications. Extensive mechanical test results including Charpy impact testing, hardness, CTOD and SSC testing will be presented. In addition Gleeble trials were carried out using different thermal cycles to simulate multilayer welding. The aim was to improve the understanding of the base material behaviour in the heat affected zone (HAZ) during welding. The microstructure was characterized by LOM, SEM and furthermore hardness and Charpy impact tests were executed. Based on the gathered knowledge and test results welding recommendations and welding strategies for high strength steel X80 seamless line pipes are deduced.

Metallurgical Design and Performance of High-Frequency Electric Resistance Welded Linepipe With High-Quality Weld Seam Suitable for Extra-Low-Temperature Services

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Shunsuke Toyoda ◽  
Sota Goto ◽  
Takatoshi Okabe ◽  
Hideto Kimura ◽  
Satoshi Igi
Keyword(s):  
Low Temperature ◽  
High Frequency ◽  
Weld Seam ◽  
Welding Process ◽  
Interface Debonding ◽  
Cleavage Crack ◽  
Maximum Point ◽  
Electric Resistance ◽  
High Quality ◽  
The Matrix

To clarify the effect of inclusions on the Charpy impact properties, the 2 mm V-notched Charpy properties of X60–X80-grades steel were numerically simulated using the finite element method code abaqus. The yield strength and the tensile strength of the steel were 562 MPa and 644 MPa, respectively. The striker's velocity and the temperature dependency of the stress–strain curve were taken into account. To estimate the effect of nonmetallic inclusions, a 200 μm long virtual inclusion with a 1 μm edge radius was situated at the maximum point of the stress triaxiality. Four types of microcrack initiation were determined: (a) ductile void generation in the matrix, (b) cleavage crack generation in the matrix, (c) void generation by inclusion fracture, and (d) void generation by matrix–inclusion interface debonding. Without inclusions, a ductile microvoid was generated when the striker stroke was 3.3 mm, independent of the temperature. With inclusions, an inclusion fracture occurred when the striker stroke was 0.6 mm at room temperature. The striker stroke decreased as the temperature decreased. Based on the above numerical estimation results, high-frequency electric resistance welded (HFW) linepipe with high-quality weld seam MightySeam® has been developed. Controlling the morphology and distribution of oxides generated during the welding process by means of temperature and deformation distribution control is the key factor for improving the low-temperature toughness. The Charpy transition temperature of the developed HFW pipe was much lower than −45 °C. Based on the low-temperature hydrostatic burst test with a notched weld seam at −20 °C, the MightySeam® weld provides a fracture performance that is the same as UOE double submerged arc welded pipe. The pipe has been used in actual, highly demanding, and severe environments.

Microstructure and Mechanical Properties of Laser Welded 316L SLM Parts

2020 ◽  
Vol 841 ◽  
pp. 306-311
Author(s):  
Timo Rautio ◽  
Jarmo Mäkikangas ◽  
Matias Jaskari ◽  
Markku Keskitalo ◽  
Antti Järvenpää
Keyword(s):  
Laser Welding ◽  
Weld Seam ◽  
Sheet Material ◽  
Base Material ◽  
Melting Process ◽  
Heat Treating ◽  
Joint Properties ◽  
Before And After ◽  
The Difference ◽  
Commercial Sheet

This paper focuses on a study conducted on laser welding of printed 316L parts that were produced with a selective laser melting process. Commercial sheet material was used as a reference for the printed 316L parts. The effect of heat treatment on joint properties, and on what stage of the process it should be applied, was studied with metallography and mechanical testing. Optical microscopy was applied to analyze the microstructure of the base material and the weld seam. Tensile testing was applied for determining monotonic strength of different structures. The printed base material showed higher strength, but lower ductility in comparison to the commercial sheet material. In the welded condition, tensile properties were impaired by the welding, but for the commercial sheet material, no clear effects were seen. The difference was hypothesized to be caused by the higher strength mismatch in the printed joints. For the welded structures, the best strength-ductility combination was achieved by heat treating the parts both before and after the laser welding.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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