bluuebunny/crossref_metadata_2025_split huggingface dataset:
ВЕНТИЛЯЦІЯ ЯК СКЛАДОВА ЕНЕРГЕТИЧНОГО ДИНАМІЧНОГО БАЛАНСУ В БУДІВЛЯХ
Authors: ДЕШКО В. І. , БІЛОУС І. Ю. , ГУРЄЄВ М. В. 
Published: March 2024

Мета. Дослідження спрямоване на аналіз динамічного енергетичного моделювання будівель з використанням програмного забезпечення EnergyPlus та DesignBuilder. Основна мета полягає в оцінці енергетичної ефективності, повітряної якості та енергетичного балансу будівель з врахуванням різноманітних аспектів, таких як повітрообмін та динамічні зміни в температурі та вологості.
Методика. В роботі використовувались програми EnergyPlus та DesignBuilder для створення детальних динамічних моделей будівель. Основна увага приділялась моделюванню повітрообміну та вивченню енергетичного балансу. Різні алгоритми моделювання повітрообміну порівнювались для визначення їх впливу на енергетичну ефективність.
Результати. Досліджено енергетичні потоки в будівлях на основі динамічних енергетичних балансів для періоду опалення. Проведено поглиблений аналіз впливу повітрообміну в динамічних енергетичних балансах досліджуваної кімнати житлової будівлі.
Наукова новизна. Це дослідження пропонує новий погляд на динамічне енергетичне моделювання будівель, розширюючи знання в цій галузі через спрямовану увагу на аспекти повітрообміну та енергетичного балансу. Результати внесуть важливий вклад у розвиток підходів до підвищення енергоефективності, створюючи нові можливості для практичного застосування в інженерному проектуванні та будівельній експлуатації.
Практична значимість. Отримані результати є важливим внеском для інженерів та проектувальників, розробляючи стратегії зменшення енергоспоживання та оптимізації енергетичного споживання будівель. Дослідження може слугувати вказівником для практичного впровадження динамічного моделювання в плануванні та експлуатації будівель для досягнення оптимальної енергоефективності.
PELAKSANAAN RESTRUKTURISASI DAN PENDEBITAN REKENING PENGELUARAN KAS NEGARA PADA KANTOR PELAYANAN PERBENDAHARAAN NEGARA KEDIRI
Authors: Muwaffaq Faris Azhar , Akhmadi Muhammad Heru 
Published: March 2024

Pengelolaan kas negara yang efektif dan efisien merupakan hal yang penting pada era perkembangan teknologi informasi saat ini. Digitalisasi pada rekening atas pengeluaran kas negara melalui kebijakan restrukturisasi rekening pengeluaran menerapkan rekening virtual pada tingkat satuan kerja. Pendebitan rekening virtual pada tingkat satuan dapat dilakukan melalui CMS (Cash Management System), kartu debit, serta penarikan tunai pada teller bank. Penelitian ini bertujuan melakukan tinjauan atas mekanisme pendebitan rekening virtual Kantor Pelayanan Perbendaharaan Negara Kediri dan kendala yang dihadapi dari penerapannya. Metode pengumpulan data yang dilakukan ialah menggunakan pendekatan penelitian kualitatif deskrpitif. Hasil penelitian menunjukkan bahwa CMS merupakan metode pendebitan yang paling sering digunakan karena paling efektif dan efisien tetapi penggunaannya hanya terbatas pada transaksi nontunai saja. Selanjutnya, metode kartu debit memiliki fleksibilitas transaksi tunai dan nontunai namun paling jarang digunakan akibat tingginya risiko kerugian biaya tambahan yang harus ditanggung oleh bendahara pengeluaran. Metode penarikan tunai melalui teller bank digunakan untuk melakukan pembayaran transaksi tunai dalam rangka menutupi kekurangan metode CMS. Bendahara pengeluaran memiliki fleksibilitas untuk melakukan pendebitan rekening melalui mekanisme yang dirasa paling efektif dan efisien sesuai dengan karakteristik penyedia.
An Investigation on Structure Stability of Advanced Austenitic Heat-Resisting Steels and Ni-Base Superalloys for 600–700 °C A-USC Power Plant Application
Authors: Xie Xishan , Chi Chengyu , Yu Qiuying , Yao Zhihao , Zhang Maichang , Hu Yaohe , Dong Jianxin , Yu Hongyao , Zhao Shuangqun , Lin Fusheng , Liu Xia , Mei Linbo , Yang Huachun , Li Mingyang 
Published: March 2024

Abstract
This overview paper contains a part of structure stability study on advanced austenitic heat-resisting steels (TP347H, Super304H and HR3C) and Ni-base superalloys (Nimonic80A, Waspaloy and Inconel740/740H) for 600-700°C A-USC fossil power plant application from a long-term joint project among companies, research institutes and university in China. The long time structure stability of these advanced austenitic steel TP347H, Super304H, HR3C in the temperature range of 650-700 °C and Ni-base superalloys Nimonic80A, Waspaloy and Inconel740/740H in the temperature range of 600-800°C till 10,000h have been detailed studied in this paper.
Creep-Rupture Behavior of Precipitation-Strengthened Ni-Based Alloys Under Advanced Ultrasupercritical Steam Conditions
Authors: Tortorelli P.F. , Unocic K.A. , Wang H. , Santella M.L. , Shingledecker J.P 
Published: March 2024

Abstract
To achieve the necessary creep-rupture lifetimes at the temperatures and pressures associated with advanced ultrasupercritical (A-USC) steam conditions (100,000 h at 100 MPa and 760°C), precipitation-strengthened nickel-based alloys are required for the superheater and reheater tubing in A-USC boilers. Two alloys were considered to have potential for this application: Inconel 740 and Haynes 282 alloy. In support of this application, creep-rupture testing of several heats of Inconel 740 was conducted over a range of temperatures and stresses to develop confidence in qualitatively predicting creep lifetimes under conditions relevant to A-USC steam conditions, with the longest rupture times exceeding 30,000 h. For comparison, the creep-rupture behavior of Haynes 282 alloy was mapped as a function of temperature and stress, but with a significantly smaller dataset. Only a small difference in creep-rupture results between Inconel 740 and Inconel 740H was found although the latter alloy showed significantly greater resistance to η phase formation during testing. Little effect of prior aging treatments (for setting the γ′ precipitate structure) on creep-rupture behavior was observed. Results from a modified power law analysis showed that, while both Inconel 740 and Haynes 282 are projected to meet the A-USC lifetime requirements, the latter offered the potential for better long-term creep resistance.
Cyclic Properties of 50Ni-24Cr-20Co-0.6Mo-1Al-1.6Ti-2Nb Alloy at Advanced USC Steam Temperature
Authors: Gururaja U V , Patra A , Mukhopadhyay P , Narayana Rao M 
Published: March 2024

Abstract
Significant development is being carried out worldwide for establishing advanced ultra supercritical power plant technology which aims enhancement of plant efficiency and reduction of emissions, through increased inlet steam temperature of 750°C and pressure of 350 bar. Nickel base superalloy, 50Ni-24Cr-20Co-0.6Mo-1Al-1.6Ti-2Nb alloy, is being considered as a promising material for superheater tubes and turbine rotors operating at ultra supercritical steam conditions. Thermal fluctuations impose low cycle fatigue loading in creep regime of this material and there is limited published fatigue and creep-fatigue characteristics data available. The scope of the present study includes behavior of the alloy under cyclic loading at operating temperature. Strain controlled low cycle fatigue tests, carried out within the strain range of 0.2%-1%, indicate substantial hardening at all temperatures. It becomes more evident with increasing strain amplitude which is attributed to the cumulative effects of increased dislocation density and immobilization of dislocation by γ′ precipitates. Deformation mechanism which influences fatigue life at 750°C as a function of strain rate is identified. Hold times up to 500 seconds are introduced at 750°C to evaluate the effect of creep fatigue interaction on fatigue crack growth, considered as one of the primary damage mode. The macroscopic performance is correlated with microscopic deformation characteristics.
Manufacturing of Trial Rotor Forging of 9%Cr Steel Containing Co and B (X13CrMoCoVNbNB9-2-1) for Ultrasupercritical Steam Turbines
Authors: Nakano M. , Kawano K. , Mikami M. 
Published: March 2024

Abstract
A 9% Cr steel containing cobalt and boron, X13CrMoCoVNbNB9-2-1, has been manufactured by electroslag remelting (ESR) to evaluate its performance and to compare its creep strength and microstructure to a forging made from electroslag hot-topping ingot. The evaluation results confirm that it is possible to produce rotor forgings with homogeneous composition and good properties by the ESR process. The results of creep rupture tests up to 5000 h indicate that the creep strength of the forging made from ESR ingot is similar to that of the forging produced by the electroslag hot-topping process. Martensitic lath microstructures with high density dislocations and the precipitations of M23C6, VX, NbX and M2X are observed after the quality heat treatments at the center portion of both forgings. There is no large difference in the martensitic lath widths, distributions, and sizes of those particles between both trial forgings.
Tribolayer Formation by Strain-Induced Transformations in Hardfacing Alloys
Authors: Smith Ryan , Siefert J. , Gandy D. , Babu S. S. 
Published: March 2024

Abstract
Hardfacing alloys are commonly used for wear- and galling-resistant surfaces for mechanical parts under high loads, such as valve seats. Cobalt-based Stellite, as well as, stainless-steel-based Norem02 and Tristelle 5183 alloys show similar microstructural features that correlate with good galling resistance. These microstructures contain hard carbides surrounded by a metastable austenite (fcc) phase that transform displacively to martensite (hcp or bcc or bct) under deformation. As a result, the transformed wear surface forms a hard layer that resists transition to a galling wear mechanism. However, at elevated temperature (350°C), the stainless steel hardfacing alloys do not show acceptable galling behavior, unlike Stellite. This effect is consistent with the loss of fcc to bcc/bct phase transformation and the increase in depth of the heavily deformed surface layer. Retention of high hardness and low depth of plastic strain in the surface tribolayer is critical for retaining galling resistance at high temperature.
Advances in Nickel Alloy Casting Production for +700 °C Applications
Authors: Birks S. , Roberts S. , Leese R. 
Published: March 2024

Abstract
The drive for reduced carbon dioxide emissions and improved efficiency in coal fire power plant has led to much work being carried out around the world with regards to material development to enable 700+°C steam temperature operation. At these elevated temperatures and pressures steels just don’t have enough strength, and typically have a temperature limit of around 620°C (possibly up to 650°C in the near future) in the HP environment. Therefore, material development has focused on nickel alloys. European programs such as AD700, COMTES, European 50+ and more recently, NextGen Power and Macplus, have investigated the use of nickel alloys in the steam turbine. Large castings have an important role within the steam turbine, because valves bodies and turbine casings are nearly always produced from a cast component. The geometry of these components is often complex, and therefore, the advantage of using castings for such items is that near net shapes can be produced with minimal machining. This is important, as nickel alloys are expensive, and machining is difficult, so castings offer an attractive cost benefit. Cast shapes can be more efficiently designed with regards to stress management. For example, contouring of fillet regions can help to reduce stress concentrations leads to reduced plant maintenance and casting complex shapes reduces the number of onsite fabrication welds to inspect during outage regimes.
Fracture of Gr. 91 Steel Longitudinal Welded Pipe under Internal Pressure Creep Condition
Authors: Yaguchi Masatsugu , Sakai Takayuki , Ogata Takashi , Matsumura Takuaki 
Published: March 2024

Abstract
An internal pressure creep test has been carried out on a Gr. 91 steel longitudinal welded pipe at 650°C to examine the type IV failure behavior of actual pipes, using a large-scale experiment facility “BIPress”, which can load internal pressure and bending force on large diameter pipes at high temperatures. The creep test was also interrupted three times to measure hardness and voids density in the HAZ region of the outer surface of the test pipe. Results of the measurement of the hardness and voids density at the interruption did not indicate creep damage accumulation. The welded pipe suddenly ruptured with large deformation, which caused crushing damage to the surrounding facility. Type IV cracking occurred in the longitudinal welded portion of the test pipe, and the length of the crack reached 5000mm. SEM observation was carried out at the cross section of the welded portion of the test pipe and voids density was measured along the thickness direction in the HAZ region. To clarify the stress/strain distribution in the welded portion, creep analysis was conducted on the test pipe, where the materials are assumed to consist of base metal, weld metal and HAZ. After stress redistribution due to creep deformation, stress and strain concentrations were observed inside the HAZ region. Then, the authors' creep life prediction model was applied to the creep test result to examine its validity to actual size pipes. It was demonstrated that the life prediction model can evaluate damage of the Gr. 91 steel longitudinal welded pipe with sound accuracy.
Creep Damage Evaluation of High Cr Ferritic Steel Based on Change in Hydrogen Desorption Characteristics
Authors: Komazaki Shin-ichi , Yamashita Hayato , Yonemura Mitsuharu , Igarashi Masaaki 
Published: March 2024

Abstract
The change in hydrogen desorption characteristic due to creep was investigated to examine the possibility of hydrogen as tracer for detecting and evaluating the creep damage accumulated in high Cr ferritic boiler steel, Gr.91. Hydrogen charging into the creep specimen was conducted by means of cathodic electrolysis. Next, the thermal desorption analyses (TDA) were carried out at temperature range from room temperature to 270°C for measuring the hydrogen evolution curve. The experimental results revealed that the amount of hydrogen desorbed during analysis, CH, increased with increasing creep life fraction, although the trend of increase in CH was strongly dependent on the stress level. Moreover, there was an almost linear correlation between the logarithm of CH measured on the creep ruptured specimen and the Larson-Miller parameter (LMP), which was approximated by “log CH = 0.39 LMP – 13.4”. This can be a criterion for creep rupture and means that as far as the CH does not reach the line, the rupture never occurs.
High Pressure Steam Oxidation: Extents and Influences
Authors: Fry A.T. , Seraffon M. , Banks J. 
Published: March 2024

Abstract
Laboratory-scale tests are frequently used to generate understanding of high-temperature oxidation phenomena, to characterise and rank the performance of existing, future materials and coatings. Tests within the laboratory have the advantage of being well controlled, monitored and offer the opportunity of simplification which enables the study of individual parameters through isolating them from other factors, such as temperature transients. The influence of pressure on the oxidation of power plant materials has always been considered to be less significant than the effects of temperature and Cr content, but still remains a subject of differing opinions. Experimental efforts, reported in the literature, to measure the influence of steam pressure on the rate of oxidation have not produced very consistent or conclusive results. To examine this further a series of high pressure steam oxidation exposures have been conducted in a high pressure flowing steam loop, exposing a range of materials to flowing steam at 650 and 700 °C and pressure of 25, 50 and 60 bar. Data is presented for ferritic-martensitic alloys showing the effect of increasing pressure on the mass change and oxide thickness of these alloys in the flowing steam loop. In addition the effect observed on the diffusion of aluminium from an aluminised coating in these alloys is also presented and the differences in the extent of diffusion discussed.
Steam Oxidation of the Novel Austenitic Steel of Fe-20Cr-30Ni-2Nb (at.%) at 973 K
Authors: Ueda Mitsutoshi , Yamashita Masakazu , Kawamura Kenichi , Takeyama Masao , Maruyama Toshio 
Published: March 2024

Abstract
Steam oxidation of a novel austenitic steel, of which composition is Fe-20Cr-30Ni-2Nb (at.%), has been conducted at 973 K to evaluate steam oxidation resistance based on detail analyses of scale morphology and scale growth. Two types of scale morphologies were observed in the solution treated sample, depending on the grain of the steel. Although thin duplex scale with the Cr-rich layer was formed in the early stage, most of the surface was covered with thick duplex scale which consists of magnetite as the outer scale and the mixture of Fe-Cr spinel and metallic Ni as the inner scale. On the other hand, surface morphology of the oxide scale was independent of grain of the steel and thick duplex scale as seen on the solution treated sample was formed on the pre-aged sample. Steam oxidation resistance of the steel is almost the same as that of commercial austenitic steels and it can be improved by the surface treatment such as shot peening. Based on the results, this steel has both enough creep rupture strength and good steam oxidation resistance for A-USC power plants.
Qualifying Welding Procedures for Repair of High Temperature Components
Authors: Newell William F. 
Published: March 2024

Abstract
Qualifying welding procedures for repair of components in high temperature service requires careful consideration of factors including identification of the materials involved, existing mechanical properties and service operating parameters such as temperature, pressure and environment. Selection of weld metals to match, under match or overmatch base material as well as direct and indirect consequences on the heat-affected zone also require evaluation. Application of post weld heat treatment and ramifications where dissimilar base materials are involved are discussed plus the necessity of conducting tests at the operating temperatures and conditions where information is not available from the literature. Each of these factors is discussed and examples provided.
Influence of Trace RE Element on Properties and Microstructures of SA335P91 Weld Metal
Authors: Du Haoyang , Du Mingliang , Yang Jian , Hou Laichang , Yang Yongmei 
Published: March 2024

Abstract
This study investigates the impact of adding small amounts of rare earth (RE) elements on the properties and microstructures of SA335P91 steel welds. The RE elements were incorporated into the weld metal using a coating process. The researchers then proposed an optimal RE formula aimed at achieving improved properties and microstructures. To evaluate the effectiveness of this approach, various tests were conducted on both welds with and without RE additions. These tests included tensile testing (both at room and high temperatures), impact testing, metallographic analysis to examine the microstructure, determination of phase transformation points, scanning electron microscopy, and X-ray diffraction. The results revealed that the addition of RE elements has the potential to enhance the properties and modify the microstructure of SA335P91 welds.
Applications of a Phase Analysis Technology to Advanced Heat Resistant Steels and Nickel-Base Superalloys
Authors: Zhifang Peng , Fangfang Peng , Fangyu Chen 
Published: March 2024

Abstract
An approach to phase analysis called multiphase separation technology (MPST) has been developed to determine phase chemistries of precipitated particles with sizes visible under SEM/EPMA observations based on the data from the conventional EDS measurements on bulk steel/alloy material samples. Quite accurate results from its applications have successfully been demonstrated by comparisons of SEM/EPMA - EDS + MPST with some other currently available means, for instance, chemical extractions (CA), TEM-EDS, AP-FIM and Thermo-Calc. etc. Applied examples regarding the relations of change in phase parameters including type, composition, volume fraction, size and distribution of the precipitated particles with material qualities, creep rupture lives, property stabilities, property recovery and boiler tube failures for some advanced heat resistant steels (P92, Super304H, HR3C, TP347HFG (H)) are given through the use of the SEM/EPMA - EDS + MPST in this contribution. Examples on phase quantifications of some nickel base superalloys (Nimonic263, Inconel 740 and Rhenium-containing alloys) are also shown to reveal the feasibility of its use in determining phase chemistries of precipitated particles under different measurement conditions. Practical applications of this combined technology to the material quality control and assessments, processing parameter improvements, as well as fracture/failure analyses of high temperature components have shown that this technology is quite convenient and effective when used for microstructural analysis purposes during R&D, manufacturing and operating processes.
Development and Evaluation of Fe/Ni Dissimilar-Weld Turbine Rotor for Advanced USC
Authors: Oinuma Shun , Miyashita Shigekazu , Fujita Yoshihiro , Yoshioka Yomei , Kubo Takahiro 
Published: March 2024

Abstract
In order to develop an Fe/Ni dissimilar-weld rotor structure for an Advanced Ultra Super Critical turbine, fundamental studies on the metallurgical properties of Fe/Ni welds are needed. In the work reported in this paper, we studied the microstructure evolution and creep rupture properties of Fe/Ni weld joints with different compositions. Investigation of thermally aged Fe/Ni diffusion couples revealed that Fe-based ferritic steel and Alloy 617 weld joints with a large difference in Cr content showed strong C diffusion at the weld interface. This decreased the creep rupture life of the weld joint, caused by coarsening of a martensitic structure near the interface. Analysis using Fe/Ni diffusion couples and thermodynamic calculations suggested that the driving force of C diffusion is the chemical potential gradient at the interface, and the difference in Cr content between Fe and Ni accelerates the C diffusion.
Creep of the Novel Austenitic Heat Resistant Steel of Fe-20Cr-30Ni-2Nb under Steam Atmosphere at 1073 K
Authors: Misosaku Yu , Tarigan Imanuel , Takata Naoki , Ueda Mitsutoshi , Maruyama Toshio , Takeyama Masao 
Published: March 2024

Abstract
In this study, we have examined the creep of a novel austenitic heat resistant steel of Fe-20Cr- 30Ni-2Nb (at.%) steel at 1073K in steam and air atmospheres. Our studied steels were Fe-20Cr- 30Ni-2Nb (base steel) and that with 0.03 at. %B (B-doped steel) . The addition of boron is to intentionally increase the area fraction of Laves phase on grain boundaries (ρ). The specimen with ρ = 43% (base steel pre-aged at 1073 K/240 h) exhibits the rupture life of 262 h, whereas the rupture life of the specimen with higher ρ of 80% (B-doped steel pre-aged at 1073 K/240 h) is 833h, which is about three times longer than that of the specimen with ρ = 43%. The specimen with ρ = 80% exhibits smaller creep rate than those with lower ρ than 43% in the entire creep stage. In addition, all specimens show the creep rupture strain of about 60%. The creep rupture life is almost same to that tested under air, whereas the creep rupture strain is slightly smaller (a few percent) than that under air. In the surface of the creep ruptured specimen in steam, the intergranular oxides associated with voids or cavities are often present and grow along grain boundaries to over 100 μm in depth. The intergranular oxidation occurs more extensively in steam rather than air. These results demonstrate that stable Fe2Nb Laves phase on grain boundary could increase the creep resistance of the present steel at 1073K without ductility loss in steam as well as air, resulting in the pronounced extension of rupture life. The intergranular oxidation accelerated by steam would not give a serious effect on the creep properties of the present steel below 103 hours in rupture life.