Materials at High Temperatures最新文献

{"title":"Steel grades 91 and 92 microstructure and precipitate evolution atlas and life assessment tool","authors":"A. Tonti, A. Alvino, A. Antonini, C. Delle Site, D. Lega, S. Matera, O. Tassa","doi":"10.1080/09603409.2023.2264061","DOIUrl":"https://doi.org/10.1080/09603409.2023.2264061","url":null,"abstract":"ABSTRACTP91 and P92 steels are widely used in power plants and petrochemical industry for long-term service components. Due to high resistance to creep, fatigue and corrosion, the use of grade 91 and grade 92 steels allows ultrasupercritical conditions (600 °C, 300 bar). To achieve this goal the alloy design was based on the following metallurgical concepts: stable tempered martensitic microstructure, precipitation strengthening through M23C6 (Cr, Fe, Mo or W carbides) and fine MX (V, Nb carbides), solution hardening through elements as Mo or Mo/W and high Cr content. This study is focused on the microstructure evolution of grade 91 and grade 92 steels under aging and creep conditions. Three sets of laboratory-aged specimens heated in oven at 550°C, 600°C and 650°C were examined. Furthermore, the influence of stress on the microstructure was evaluated. The microstructures were characterized by several means of investigations and the results were compared to literature.KEYWORDS: MXM23C6Laves phaseZ phasecreep cavityinclusions Disclosure statementNo potential conflict of interest was reported by the authors.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135967763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uniform elongation measurements on creep specimens by a novel 3D-scanning system","authors":"C. Kontermann, A. Erbe, V. Knauthe, M. von Buelow, T.-U. Kern, M. Oechsner","doi":"10.1080/09603409.2023.2261783","DOIUrl":"https://doi.org/10.1080/09603409.2023.2261783","url":null,"abstract":"ABSTRACTThe ductility of a material represents a very important value for both the classification and application of high-temperature alloys in real components. Commonly, different values have been defined and can be used to characterise the ductility of the material. Within this work, a 3D-scanning system has been developed which allow a highly precise digital reconstruction of fractured creep specimens. The digital reconstruction is used to compare and refine conventions for determining one of the ductility candidate values, the uniform elongation, in a consistent, robust and objective way. By utilizing this system, a large amount of long-term creep specimens were re-evaluated including P92 samples with challenging, since macroscopically low ductility values. The results will be discussed in by providing uniform elongation trends and by the use of the Ductility Evaluation of Creep Specimens (DECS) diagram.KEYWORDS: Uniform elongation3D-Scannercreep ductility AcknowledgmentsThe underlying research project (FVV project no. 1371) was performed by the Institute of Materials Technology of the Technical University Darmstadt, by the Interactive Graphics Systems Group and by the Materials Testing Institute at the University of Stuttgart. The research project was funded by the AVIF (Research Association for the Iron and Metal Processing Industry eV, AVIF No. A314). The authors gratefully acknowledge the support received from the funding organisation, from the FVV eV and from all scientific and industry experts involved in this project.Disclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135095099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rupture strength prediction of martensitic power plant steels","authors":"Z. Guo, J. Hu, N. Saunders, J.Ph. Schillé","doi":"10.1080/09603409.2023.2265261","DOIUrl":"https://doi.org/10.1080/09603409.2023.2265261","url":null,"abstract":"ABSTRACTThe creep resistance of martensitic power plant steels depends strongly on the dispersion of various types of precipitates in the microstructure. Reliable prediction of rupture strength of such alloys thus demands accurate description of the microstructure evolution during service. A material model that calculates the simultaneous precipitation kinetics and hardening in these steels has been reported previously. The creep rupture model reported here is a natural extension of the previous research. This model has been validated against experimental creep rupture data of wide-used 9–12% Cr steels. It allows the effect of variation in alloy conditions, such as composition and heat treatments, on rupture strength to be quantitatively evaluated for a given alloy grade. Results show that such variations can lead to significant differences in the calculated rupture strength, which are believed to be largely responsible for the wide scatter in the experimental data.KEYWORDS: Rupture strengthrupture lifeprecipitationpower plant steelsmaterials modelling Disclosure statementNo potential conflict of interest was reported by the authors.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135738806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term creep behaviours and structural stabilities of austenitic heat-resistant stainless steels","authors":"O. Öhlin, R. Siriki, G. Chai","doi":"10.1080/09603409.2023.2263719","DOIUrl":"https://doi.org/10.1080/09603409.2023.2263719","url":null,"abstract":"ABSTRACTFor heat resistant alloys, long-term structural stability at high temperatures is a critical issue for alloy design and applications. In this paper, the long-term creep behaviours and structural stabilities of six heat resistant high Ni alloys and austenitic stainless steels have been studied. The longest creep rupture life is up to 359 283 hours. High Ni and Cr alloys show a good combination of high creep and oxidation resistances. Precipitation of nano MX particles with a very low growth rate improves long-term creep resistance at high temperatures. Long-term stable multiple nanoprecipitates of MX, Cu-rich, Laves and M23C6 phases can greatly contribute to the creep strength. Low Ni austenitic stainless steels show comparatively low oxidation and creep resistances. It was first found that at 800°C, Cr2N could form in the low Ni steel with a long-term crept by the absorption of nitrogen from the air into the matrix.KEYWORDS: Creepaustenitic stainless steelNi based alloystructural stabilitymicrostructure AcknowledgmentsThis paper is published by permission of Alleima EMEA AB. The supports of Dr Tom Eriksson and Mr Martin Östlund are greatly acknowledged.Disclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135537085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep of IN738LC manufactured with laser powder bed fusion: effect of build orientation and twinning","authors":"Sandra Megahed, Karl Michael Krämer, Christoph Heinze, Christian Kontermann, Annett Udoh, Stefan Weihe, Matthias Oechsner","doi":"10.1080/09603409.2023.2261665","DOIUrl":"https://doi.org/10.1080/09603409.2023.2261665","url":null,"abstract":"ABSTRACTThe microstructural anisotropy caused by the highly oriented solidification of the metal Laser Powder Bed Fusion (PBF-LB/M) process affects mechanical short- and long-term properties. Component build orientation influences grain morphology and orientation, and thus, mechanical properties. While the creep behaviour of samples manufactured parallel and perpendicular to the build direction are studied intensively, the 45° build orientation remains uncharacterised. In this study, IN738LC creep samples are manufactured via PBF-LB/M in three build orientations (0°, 45° and 90°). While the results of 90° and 0° are as expected, where 90° achieves the longest time to rupture and largest rupture strain, the 45° specimen shows the least fracture time. Differences in microstructure and twinning behaviour are identified as one of the root causes for this unexpected behaviour. This study discusses the correlation between microstructure, twinning and build orientation and their effect on creep behaviour, with special focus on the 45° build orientation.KEYWORDS: Laser powder bed fusionIN738LCbuild orientationcreepmicrostructuretwinning Disclosure statementNo potential conflict of interest was reported by the author(s).PatentsThere are no patents resulting from the work reported in this manuscript.Notes1. Hausner ratio, h = .Tapped Powder DensityBulk Powder Density2. Volume energy density,EV = Laser PowerScan Speed×Hatch Distance×Layer ThicknessAdditional informationFundingThe research project (FVV project no.1401) was performed by the Institute of Materials Technology of the Technical University Darmstadt under the guidance of Prof. Dr.-Ing. Matthias Oechsner and by the Materials Testing Institute at the University of Stuttgart under the guidance of Prof. Dr.-Ing. Stefan Weihe. Based on a decision taken by the German Bundestag, it was supported by the Federal Ministry for Economic Affairs and Climate Action (BMWK) and the AIF (German Federation of Industrial Research Associations eV) within the framework of the industrial collective research (IGF) programme (IGF No. 21220 N/1) The authors gratefully acknowledge the support received from the funding organisations, from the FVV eV and from all those involved in the project.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135816259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEM and EDX analysis of erosion products formed on steam turbine blade","authors":"Pooja Rani, Atul Kumar Agrawal","doi":"10.1080/09603409.2023.2264058","DOIUrl":"https://doi.org/10.1080/09603409.2023.2264058","url":null,"abstract":"ABSTRACTWater droplet erosion (WDE), which is brought on by the high-energy impact of liquid water droplets, is a serious problem for steam turbine blades. Nevertheless, rather than addressing the WDE of actual steam turbine blades, the majority of the published research on this issue uses laboratory test rigs. In this study, scanning electron microscopy and energy-dispersive X-ray analysis are used to examine how the surface of low-pressure steam turbine blades that had been in service eroded over time. The results of this study provide valuable insights into the microstructural features and elemental composition of X20Cr13 steel in steam turbine blades, as well as the factors that can contribute to damage and failure.KEYWORDS: LP turbine bladeX20Cr13fractographyerosion pitsScanning Electron Microscopy (SEM)Energy-Dispersive X-ray (EDX) AcknowledgmentsThe authors are grateful to Dr. M.K. Sharma, Technical Director: AEQUITAS VERITAS INDUSTRIAL SERVICES (AVIS) laboratory, for helping us in conducting the experiments and Mr. D.C. Nirmal, Sr. DGM (STE-BHEL Bhopal), Mr. Manoj Yadav, Manager (COE-BHEL BHOPAL) for technical guidance on steam turbines.Disclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simplicity, accuracy and confidence in predicting long-term rupture properties from short-term data: a study of four heats of 2.25Cr1Mo0.3V steel","authors":"John Bolton","doi":"10.1080/09603409.2023.2276548","DOIUrl":"https://doi.org/10.1080/09603409.2023.2276548","url":null,"abstract":"ABSTRACTModels of rupture data formulated recently by conventional methods for different heats of a 2.25Cr1Mo0.3 V pressure vessel steel are compared to models of the same data formulated by the P-NID (parametric, numerical isothermal datum) procedure. The alternative models are evaluated according to the accuracy with which they replicate the data. Confidence in the prediction of long-term properties from these models is discussed, and it is argued that major extrapolations may be considered reliable for models that satisfy the simple criteria of accuracy of the P-NID procedure.KEYWORDS: Creep rupture2.25Cr1Mo0.3V steelrupture modellinglong-term extrapolationP-NID procedurecriteria of accuracy Disclosure statementNo potential conflict of interest was reported by the author(s).","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134948872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Re/Ru on constituents distribution and creep performance of nickel-based single crystal alloys","authors":"Songwen Tian, De-long Shu, Lirong Liu, S. Tian","doi":"10.1080/09603409.2023.2244297","DOIUrl":"https://doi.org/10.1080/09603409.2023.2244297","url":null,"abstract":"ABSTRACT The effects of Re/Re on the element distribution and creep performance of nickel-based single crystal alloy by using atom probe tomography (APT) and creeping property testing has been studied. Results show that the elements Re, Ru, W, Mo, Cr, and Co are the former of γ phase; the elements are distributed in γ and γ‘ phases of two alloys according to various ratios. Some of the Ru atoms in Re-containing alloy make more Al, Ta atoms are dissolved in γ matrix and make more Mo, W, and Re atoms dissolving in γ‘ phase, which increases the alloying degree of γ“, γ phases to enhance the strength and creep resistance of alloy. Particularly, the Re and W atoms dissolved in γ” phase are excluded, during creep, for the enrichmrnt in γ phase near the interface to form their peak content; the lattice distortion coming from the enriched Re and W atoms restrains dislocations gliding to delay the γ’ phase from being sheared. The deformed mechanisms of alloy in the later stage of creep are the dislocations gliding in γ phase and shearing γ’ phase. Wherein, the dislocations of shearing γ’ phase are both glided on {111} planes and cross-glided from {111} to {001} planes to form the KW locks, the ones that restrain the gliding and cross-gliding of dislocations for improving the creep resistance of alloy. While the interaction of the Ru with Re and W atoms make some Reand W atoms reserved in the γ′ phase to delay the diffusion of other elements, which prevents the KW locks from being released, to keep the good resistance of alloy.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81653619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A statistical microstructures-based method for the prediction of mechanical properties in nickel-based single crystal alloys","authors":"H.T. Li, X.M. Wang, Z.X. Li, H. Liu, S. Qiao, Z. Yv, K. Zhang, L. Li","doi":"10.1080/09603409.2023.2243094","DOIUrl":"https://doi.org/10.1080/09603409.2023.2243094","url":null,"abstract":"ABSTRACT The γ/γ’ microstructure is a key factor for the mechanical performance of nickel-based single crystal superalloys. Experimental results have shown that the size and shape of the γ’ precipitates are not uniform and follow certain probability distributions. In order to study the effect of the microstructure on the mechanical behavior of the superalloys, a method is proposed to reproduce its initial microstructure with the distribution function of its γ′ particle size. The effect of different microstructures on the creep behavior at different locations of a real blade is predicted to demonstrate the application of the method. It can be found from the simulation results that the mechanical behavior of the blade is related to not only the thickness of the blade wall but also the position in the blade.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79985966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constitutive equations to correlate uniaxial creep behaviour vs stress and temperature for inconel 718","authors":"A. Lo Conte","doi":"10.1080/09603409.2023.2240632","DOIUrl":"https://doi.org/10.1080/09603409.2023.2240632","url":null,"abstract":"ABSTRACT The paper presents uniaxial creep tests conducted on Inconel 718 superalloy, reporting and describing the results obtained. The creep strain curves have been examined in different scenarios: by varying the initial applied stress, by varying the initial test temperature, and by considering the orientation of the specimens with respect to the direction of the material processing. Finally, ductility and deformation accumulation rate have been evaluated to highlight the effect of the precipitation anisotropy on the creep behaviour. Given the complexity of the creep phenomenon, each phase of the creep strain curves of Inconel 718 has been analysed independently, using constitutive models taken from the literature that allow to describe the phenomenon in pure metals and in some alloys.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76976429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}