bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Burial Depth and Soil Thermal Conductivity on Heat Transfer in Buried CO2 Pipelines for CCS: A Parametric Study
Authors: Olugunwa Babafemi , Race Julia , Tezdogan Tahsin 
Published: January 2021

Abstract
Pipeline heat transfer modelling of buried pipelines is integral to the design and operation of onshore pipelines to aid the reduction of flow assurance challenges such as carbon dioxide (CO2) gas hydrate formation during pipeline transportation of dense phase CO2 in carbon capture and storage (CCS) applications. In CO2 pipelines for CCS, there are still challenges and gaps in knowledge in the pipeline transportation of supercritical CO2 due to its unique thermophysical properties as a single, dense phase liquid above its critical point. Although the design and operation of pipelines for bulk fluid transport is well established, the design stage is incomplete without the heat transfer calculations as part of the steady state hydraulic and flow assurance design stages. This paper investigates the steady state heat transfer in a buried onshore dense phase CO2 pipelines analytically using the conduction shape factor and thermal resistance method to evaluate for the heat loss from an uninsulated pipeline.
A parametric study that critically analyses the effect of variation in pipeline burial depth and soil thermal conductivity on the heat transfer rate, soil thermal resistance and the overall heat transfer coefficient (OHTC) is investigated. This is done using a one-dimensional heat conduction model at constant temperature of the dense phase CO2 fluid. The results presented show that the influence of soil thermal conductivity and pipeline burial depth on the rate of heat transfer, soil thermal resistance and OHTC is dependent on the average constant ambient temperature in buried dense phase CO2 onshore pipelines. Modelling results show that there are significant effects of the ambient natural convection on the soil temperature distribution which creates a thermal influence region in the soil along the pipeline that cannot be ignored in the steady state modelling and as such should be modelled as a conjugate heat transfer problem during pipeline design.
Burst Pressure Prediction of Pipes With SCC Colonies: Evaluation of Intelligent Flaw Interaction Rules Using Full-Scale Burst Tests
Authors: Wang Bo , Liu Banglin , Wang Yong-Yi , Wang Alex , Rapp Steve 
Published: January 2021

Abstract
This is the second paper in a two-paper series which covers the PRCI-funded work aimed at the development of intelligent flaw interaction rules (termed PRCI-CRES SIA-1-5 rules). The first paper focused on the development of the rules using numerical analyses. This paper covers the evaluation of the rules through full-scale burst tests and accompanying small-scale material tests.
Four full-scale burst tests were conducted on 20” and 18” OD pipe segments with SCC. The SCC colonies on the test sections were inspected using MPI, PAUT, ECA, and IWEX. The small-scale material tests were conducted to measure pipe tensile strength and Charpy impact energy. The four test sections were pressurized until burst. The burst tests were recorded using multiple video cameras to capture the global behavior and detailed crack opening process at the burst locations. With the videos and the post-test examination of the failure surfaces, the full-scale burst tests provide not only the burst pressure but also information for the validation of the fundamental principles of the new interaction rules.
The modified Ln-sec method was used to predict the burst pressure using the equivalent crack size from different flaw interaction rules and the measured pipe material properties. The PRCI-CRES SIA-1-5 rules were found to provide the most accurate and precise burst pressure prediction when factors other than flaw interaction rules remain the same.
The application of the PRCI-CRES SIA-1-5 rules can reduce unnecessary hydrotests and/or other remediation actions with accurate, not overly conservative, burst pressure prediction.
Weld Hydrogen Cracking Susceptibility
Authors: Dinovitzer A. , Moulton J. , Quintana M. , Lazor R. 
Published: January 2021

Abstract
Weld hydrogen cracking has been recognized as an issue of concern and a wide range of hardenability criteria and single pass weld testing techniques have been developed to demonstrate material weldability, however, hydrogen cracks continue to be identified in welds. The potential for hydrogen cracking is related to the presence of hydrogen, the local tensile strain state and the susceptibility of the material microstructure. The weldment slow bend test and hydrogen effusion and cracking model has been used in Pipeline Research Council International (PRCI) research reported in this paper to support the development of an understanding of the interaction of these factors in promoting hydrogen cracking. The slow bend testing procedure is described with examples of the effects of increasing hydrogen and/or strain conditions are used to illustrate hydrogen cracking susceptibility. The slow bend testing procedure was applied to a range of steel weld metals to develop an understanding of the factors which make one more or less susceptible to hydrogen cracking. Combining the results of slow bend testing, the susceptibility of deposited shielded metal arc weld material to hydrogen cracking is defined using a hydrogen susceptibility curve that establishes the critical strain to form a crack as a function of hydrogen concentration. Cracking susceptibility is described through the definition of material ductility and embrittlement indices, which are derived from the hydrogen susceptibility curves. Cracking susceptibility is then correlated with mechanical, chemical and microstructure properties of the deposited welds. This model to predict weld metal hydrogen cracking susceptibility was developed to support electrode selection and welding procedure development to preclude hydrogen cracking. The results in this paper can be used to reduce the risk of hydrogen cracking and support the development of industry guidance.
Microstructure Transformation and Mechanical Properties of X80 Large Diameter Thick Wall Induction Heating Bend for Low Temperature Service
Authors: Liu Yu , You Zongbin , Yan Lijun 
Published: January 2021

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.
Formulation of 3D Soil Springs for Pipe Stress Analyses
Authors: Barrett John , Phillips Ryan 
Published: January 2021

Abstract
Interdependence between pipe-soil interaction springs in a pipe stress analysis should be considered. This example focused on a single pipe configuration “wished” in place in a clay soil. A conventional pipe stress analyses often idealizes the pipe soil interaction with a beam-spring finite element model where independence is assumed between reactions in axial, lateral and vertical directions. There is however interdependence between these springs as recognized in recent Pipeline Research Council International (PRCI) guidelines. For a frictional interface, axial resistance can be much higher than indicated by PRCI guidelines when accounting for increased lateral and vertical bearing pressure. At the same time, lateral and vertical capacities are shown to be reduced in comparison to pure vertical and lateral loading directions. This paper highlights the development of a 3D soil-spring interaction model based on a continuum finite element analysis approach. By developing a soil capacity envelope based on 3D continuum modeling, updated soil springs can reflect modified capacities depending on the direction of pipe movement. For the landslide scenarios considered in application of the model, the directional dependency is shown to change the accumulated plastic strain profile in the pipe.
Time Dependence of Hydrogen Induced Cracking of X70 Pipeline Steel Under Severe and Mild Sour Service Conditions Using Ultrasonic Analysis
Authors: Gawor S. , Wiskel J. B. , Ivey D. G. , Liu J. , Henein H. 
Published: January 2021

Abstract
A standard NACE hydrogen induced crack test was used to evaluate the resistance of two compositions of X70 steel (X70-X (Ca/S ratio of 2.5) and X70-B (Ca/S ratio of &lt; 0.5)) under severe (pH = 2.7 and 100% H2S) and mild (pH = 5.5 and 100% H2S) sour service conditions. An ultrasonic technique was developed to quantify the severity of hydrogen cracking in both steels as a function of test conditions, steel type and time. In this procedure, a series of local ultrasonic measurements was taken for each test sample to determine a local crack to backwall signal ratio (LCBR). The LCBR values were integrated over the entire sample to give a global crack to backwall ratio (GCBR). A larger GCBR value corresponds to greater hydrogen cracking severity in the sample. Energy dispersive X-ray (EDX) spectroscopy and glancing angle X-ray diffraction (XRD) were used to characterize the surface corrosion products that formed during testing. For severe sour service conditions, the GCBR value reached an asymptotic value of approximately 33% and 47% for X70-X (after 4 days) and X70-B (after 2 days) steels, respectively. For mild sour service conditions, no cracking was observed for testing of less than 16 days. After 32 days, X70-B showed a GCBR of approximately 18%. The onset of cracking of X70-X steel occurred between 32 and 64 days. Samples tested for 64 days showed a GCBR of 30% and 16% for X70-X and X70-B, respectively.
Glancing XRD measurements showed the presence of surface FeS on both steels tested under mild sour service. Quantitative XRD (QXRD) analysis was used to obtain the surface coverage of FeS as a function of test time. EDX mapping confirmed the presence of a high sulfur content over a significant fraction of the surface. XRD measurements of X70-B steel under severe sour service after 8 days did not show a significant amount of FeS. The surface FeS is believed to alter hydrogen ingress into the steel, making it difficult to directly compare measured GCBR values obtained under mild and severe sour service.
Evaluation of Contacting Effect Between Tool and Workpiece on Vibration Characteristics of NC Machine Tools
Authors: Hokazono Taisuke , Sato Ryuta , Nishida Isamu , Shirase Keiichi 
Published: January 2021

Abstract
It is expected that the vibration characteristics of NC machine tools are affected by the contact between the tool and the workpiece during the cutting operations. However, the influences of the contact have not been clarified up to now. In this study, a method to evaluate the contacting effect and evaluated results are described. Frequency response of a vertical type milling machine during cutting operation is evaluated in this study. The evaluation tests of the contacting effect are carried out with and without cutting operations. In order to clearly evaluate the influence of the contact between a tool edge and a workpiece, boring operations of 50 mm diameter are carried out. The frequency responses are measured by using feed motor torque. Impulse signal is applied to the motor torque command during the cutting operations to oscillate the machine tool, and the axial acceleration of the table is measured to obtain the frequency responses. The impulse signal can be applied by refereeing the spindle rotational angle to control the relationships between the cutting edge and workpiece surface. As the results of the evaluations, it is clarified that the proposed method can evaluate the influence of the contact adequately. The natural frequency slightly increases and the vibration amplitude decreases when the tool contacts with the workpiece, regardless of whether non-cutting or cutting. It has also been confirmed that the vibration amplitude of the frequency characteristics is changed due to the contact length and the relative direction of the cutting edge.
Experimental Investigation Into the Spatter Particle Behaviour of Maraging Steel During Selective Laser Melting
Authors: Furumoto Tatsuaki , Egashira Kyota , Oishi Kazushi , Abe Satoshi , Hashimoto Yohei , Koyano Tomohiro , Hosokawa Akira 
Published: January 2021

Abstract
The quality of built parts by selective laser melting (SLM) relies on the comprehension of the phenomena that takes place during the melting and solidification of the metal powder. The scattering of spatter particle as liquid metal during SLM process affects the layer consolidation of powder bed in addition to the surface quality of built part.
The present study is focused on the spatter particle behaviour of maraging steel during SLM to achieve a thorough understanding of the phenomena that occur during the melting and fusing of the metal powder. The spatter particles are tracked using high speed imaging, and the effects of the process parameters on the spatter particle behaviour are investigated. The spatter particles ejected from the melt pool are also physically and chemically evaluated.
The results showed that the spatter particles were classified as being spherical or satellite types, according to their scattered volumes; some spatter particles were larger than the particles in the initial metal powder. Most spatter particles were ejected from the droplet formed around the melt pool and from the melted powder in front of the melt pool; the number of spatter particles ejected from the melt pool was relatively low. The surface roughness affected the generation locations and tracks of the spatter particles, and the substrate surface wettability was the principal factor affecting the spatter particle behaviour.
Fabrication of Flexible Interposer Using Printing Method
Authors: Furuta Atsuhiro , Honjo Kazuki , Taniguchi Jun 
Published: January 2021

Abstract
In recent years, flexible electronic devices such as printed electronics are gathering attention. To make flexible connect between one circuit device and another circuit device, interposer is necessary. However, most of conventional interposers are not flexible, because there are made of silicon or glass substrate. To solve this problem, we have been developed fabrication process of flexible interposer.
Master mold was fabricated by photolithography process. First, SU-8 resist was coated on silicon substrate with 5μm thickness. Then, photolithography process was carried out to SU-8 resist. After development, pillar shape master molds with diameters of 10 or 20 μm were obtained. After release coating of master molds, hole patterns for vias were transferred by UV nanoimprint lithography. The obtained hole patterns were diameter of 10 μm or 20 μm, and pitch of 21.0 μm and 40.1 μm, respectively. Next, these holes were filled with silver ink by roll press method. Then, sintering process was carried out to evaporate of solvent of silver ink. After that, flexible interposer was obtained.
As a result, we have been succeeded in filling the holes array with silver ink. Obtained interposer vias, which were silver region, were 8.2 μm diameter and 3.3 μm height, or 20.3 μm diameter and 5.3 μm height for 10 mm square size.
Tool Path Generation for Five-Axis Controlled Machining of Free-Form Surface Using Barrel Tool: Control of Contact Point on Cutting Edge
Authors: Suzuki Tomonobu , Morishige Koichi 
Published: January 2021

Abstract
This study aimed to improve the efficiency of free-form surface machining by using a five-axis controlled machine tool and a barrel tool. The barrel tool has cutting edges, with curvature smaller than the radius, increasing the pick feed width compared with a conventional ball end mill of the same tool radius. As a result, the machining efficiency can be improved; however, the cost of the barrel tool is high and difficult to reground. In this study, a method to obtain the cutting points that make the cusp height below the target value is proposed. Moreover, a method to improve the tool life by continuously and uniformly changing the contact point on the cutting edge is proposed. The usefulness of the developed method is confirmed through machining simulations.
Influence of Tool Path When Groove Shape Machining Using Ceramic End Mill on Tool Cutting Edge
Authors: Hasegawa Masanobu , Ichikawa Kohei 
Published: January 2021

Abstract
In recent years, the application of ceramic end mill has been studied for the purpose of improving the efficiency of end milling of difficult-to-cut materials such as Ni-base heat resistant alloys. However, although there are cases of application in simple shape and continuous cutting, there are few cases of application in groove shape and intermittent cutting. Because ceramic end mill is not recommend for interrupted cutting. On the other hand, the tool path for actual part machining, such as impeller machining by a conventional carbide end mill, often changes the tool direction by air cutting. In addition, because there are restrictions on the shape of actual parts, air cut may be unavoidable. Therefore, it is important to clarify the effect of intermittent cutting, and to understand the effects and issues when using a continuous cutting tool path.
In this study, the relationship between the tool path and the tool edge condition was verified by the cutting test of the groove shape of Inconel 718 with a ceramic end mill. As a result, it was clarified that the tool path with intermittent air cut has an effect on the cutting edge. In addition, the relationship with the damage to the cutting edge when the number of cutting tooth and the cutting action in the axial direction were changed in a continuous cutting tool path was clarified.
Investigation of Correlation Between Process Energy Balance and Phase Shift Variation of Chatter Vibration in Spindle Speed Variation
Authors: Yamato Shuntaro , Matsuzaki Hirohiko , Ito Takamichi , Kakinuma Yasuhiro 
Published: January 2021

Abstract
It is widely known that the spindle speed variation (SSV) is an effective technology for chatter suppression, especially in the turning or boring process. Its simple optimal design, however, is not a simple task. In the past, certain research works considered the chatter onset from the perspective of process energy balance in a vibration cycle. The phase shift between previous (i.e., outer modulation) and present vibrations (i.e., inner modulation) of chatter is a key factor in the process energy balance. The SSV can be conceptually interpreted as a technique that continuously perturbs the phase shift between the inner and outer modulations, thereby changing the process energy balance. Simply put, the chatter energy can be controlled by applying the SSV to suppress the chatter. This study investigates the correlation between the process energy balance and phase shift behavior in the sinusoidal SSV through numerical energy simulation. The results indicate that the phase shift at the maximum spindle speed is an important factor to minimize the total energy balance (i.e., to dissipate the chatter energy) in the SSV cycle. This probably corresponds to the fact that the beat vibration tends to occur near the maximum spindle speed in the SSV. The insights gained from this study are anticipated to serve as a guideline for shaping the phase shift profile in the SSV to effectively suppress chatter vibration.
On-Machine Estimation of Workpiece Deformation for Thin-Walled Parts Considering Fixture Clamping Sequence
Authors: Zeng Jingkai , Teramoto Koji , Wu Dongjin , Matsumoto Hiroki 
Published: January 2021

Abstract
Due to the higher structure efficiency and lightweight characteristic, thin-walled parts are widely used in the modern manufacturing industry. However, from another point of view, these parts are complex in structure, weak stiffness and high precision demand. During the machining process, because of the material properties and structural characteristics, the action of elastic deformation in machining is heavily affected by the accuracy of thin-walled parts. Recently, novel near-net-shape machining methods which can be applicable to small-lot production such as thin-walled casting, additive manufacturing, and so on becomes common technology.
Finish machining of these thin-walled and complex shape workpiece is an important target of machining. In the small lot production, most of fixturing process is executed as manual operations, which generate large process variations. These variations lead to deteriorate machining accuracy. Especially, the wrong operation for the fixture clamping sequence generates different workpiece deformation. The objective of this research is to estimate actual workpiece deformation by utilizing locally measured strains and fixturing simulation in order to detect unallowable workpiece deformation caused by the wrong clamping sequence.
In this research, workpiece deformations for different clamping sequences are evaluated based on the engineering experiments. Verifications of estimated workpiece deformations are carried out. Through this research, we can effectively estimate the workholding situation of the thin-walled parts during the machining process.
Surface Roughness Analysis for Radius End Mill in Cross Feed Direction Both Contour and Scanning Line Machinings
Authors: Narita Hirohisa 
Published: January 2021

Abstract
An optimum experimental condition, which realize good surface roughness in cross direction both contour and scanning lines, for radius end mill against some inclined surfaces is obtained and some features is these cutting processes is discussed in this paper.
The optimum experimental condition, which consists of cutting type (or feed direction), spindle speed, feed rate, depth of immersion, inclination angle, corner radius of end mill and cross feed, is obtained and the influence degree of these parameters is calculated by using Taguchi method. The experiment is carried out based on L18 orthogonal array. Based on the influence degree and geometric contact status due to unique shape of radius end mill, some feature of radius end milling is introduced.
As a result of the contour line machining, a scallop height is very influenced by the inclination angle and the corner radius, and surface machined by bottom edge must not be remained. Regarding the scanning line machining, “go-up” is good for the feed direction. Big corner radius is also suitable because side edge does not contact to workpiece. In other words, the cutting force in radial direction becomes small. Furthermore, the surface roughness of the scanning line machining is smaller than the one of the contour line machining.