Pub Date : 2023-09-03DOI: 10.1080/09603409.2023.2264058
Pooja Rani, Atul Kumar Agrawal
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).
摘要液态水水滴的高能冲击引起的水滴侵蚀是汽轮机叶片面临的一个严重问题。然而，大多数发表的研究并没有解决实际汽轮机叶片的WDE问题，而是使用实验室测试台。在这项研究中，使用扫描电子显微镜和能量色散x射线分析来研究低压汽轮机叶片表面随着时间的推移是如何被侵蚀的。本研究结果为了解汽轮机叶片X20Cr13钢的显微组织特征和元素组成，以及可能导致损坏和失效的因素提供了有价值的见解。作者感谢AEQUITAS VERITAS工业服务(AVIS)实验室技术总监M.K. Sharma博士帮助我们进行了实验，感谢Dr. dc Nirmal，高级DGM (st - bhel Bhopal)， Mr. Manoj Yadav，经理(COE-BHEL Bhopal)对汽轮机的技术指导。披露声明作者未报告潜在的利益冲突。
{"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":"12 1","pages":"0"},"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}
Pub Date : 2023-09-03DOI: 10.1080/09603409.2023.2276548
John Bolton
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).
{"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":"1 1","pages":"0"},"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}
Pub Date : 2023-08-14DOI: 10.1080/09603409.2023.2244297
Songwen Tian, De-long Shu, Lirong Liu, S. Tian
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.
{"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":"3 1","pages":""},"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}
Pub Date : 2023-08-03DOI: 10.1080/09603409.2023.2243094
H.T. Li, X.M. Wang, Z.X. Li, H. Liu, S. Qiao, Z. Yv, K. Zhang, L. Li
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.
{"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":"4 1","pages":""},"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}
Pub Date : 2023-07-26DOI: 10.1080/09603409.2023.2240632
A. Lo Conte
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.
{"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":"50 1","pages":""},"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}
Pub Date : 2023-07-19DOI: 10.1080/09603409.2023.2237296
Y.X. Kang, Y. Bai, Y. Wang, X. Su
{"title":"Degradation and failure of a novel double-layer LC/YSZ thermal barrier coating in a burner rig corrosion test","authors":"Y.X. Kang, Y. Bai, Y. Wang, X. Su","doi":"10.1080/09603409.2023.2237296","DOIUrl":"https://doi.org/10.1080/09603409.2023.2237296","url":null,"abstract":"","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":"145 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76082699","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}
Pub Date : 2023-06-11DOI: 10.1080/09603409.2023.2220229
R. Higginson, G. Tatlock
{"title":"Microscopy of oxidation 11","authors":"R. Higginson, G. Tatlock","doi":"10.1080/09603409.2023.2220229","DOIUrl":"https://doi.org/10.1080/09603409.2023.2220229","url":null,"abstract":"","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":"175 1","pages":"259 - 259"},"PeriodicalIF":1.3,"publicationDate":"2023-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84470814","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}
Pub Date : 2023-06-10DOI: 10.1080/09603409.2023.2222522
N. Hiyoshi, Y. Saitou
ABSTRACT The high-temperature creep properties of Ti43Al5V4Nb were investigated experimentally and analyzed numerically. Creep testing of forged Ti43Al5V4Nb at 650°C and 760°C was conducted to investigate the creep rupture lifetime and high-temperature properties. Steady-state and accelerated creep regions were dominant in the high-temperature environment, indicating rupture ductility. The creep rupture lifetime in the range of 600°C−800°C was evaluated uniformly using the Larson – Miller and Orr – Sherby–Dorn parameters. The θ-projection method can be used to draw creep curves for experimental data up to a lifetime ratio of 0.9, and it was possible to represent the strain immediately before rupture.. The creep rupture lifetime could be predicted within a factor of two using the predicted minimum strain rate and the Monkman – Grant law. A Blackburn-type method was found to represents the transition and steady-state creep ranges accurately. Thesemethods were effective in predicting the 1% strain occurrence time
{"title":"Creep rupture lifetime evaluation and creep deformation analysis using θ-projection and Blackburn-type methods for forged Ti43Al5V4Nb","authors":"N. Hiyoshi, Y. Saitou","doi":"10.1080/09603409.2023.2222522","DOIUrl":"https://doi.org/10.1080/09603409.2023.2222522","url":null,"abstract":"ABSTRACT The high-temperature creep properties of Ti43Al5V4Nb were investigated experimentally and analyzed numerically. Creep testing of forged Ti43Al5V4Nb at 650°C and 760°C was conducted to investigate the creep rupture lifetime and high-temperature properties. Steady-state and accelerated creep regions were dominant in the high-temperature environment, indicating rupture ductility. The creep rupture lifetime in the range of 600°C−800°C was evaluated uniformly using the Larson – Miller and Orr – Sherby–Dorn parameters. The θ-projection method can be used to draw creep curves for experimental data up to a lifetime ratio of 0.9, and it was possible to represent the strain immediately before rupture.. The creep rupture lifetime could be predicted within a factor of two using the predicted minimum strain rate and the Monkman – Grant law. A Blackburn-type method was found to represents the transition and steady-state creep ranges accurately. Thesemethods were effective in predicting the 1% strain occurrence time","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":"18 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2023-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89388960","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}
Pub Date : 2023-06-08DOI: 10.1080/09603409.2023.2219875
B. Pint, Y. F. Su, M. Lance, R. Pillai, J. Keiser
ABSTRACT Direct-fired supercritical CO2 (sCO2) power cycles are being commercialised to revolutionise fossil energy as a low-emission power source. To lower the cost of this technology, less expensive steels are needed in the lower temperature segments of the cycle. However, there are concerns about internal carburisation of steels in sCO2. 1 A consistent observation is that thin, Cr-rich oxides appear to reduce C ingress compared to thick Fe-rich oxides formed on 9–12% Cr ferritic-martensitic steels. Advanced austenitic stainless steels (SS) like alloy 709 (20Cr-25Ni) are able to continue to form Cr-rich oxides at 650°C, while a conventional type 316 H SS formed a Fe-rich scale. The C diffusion profiles in SS specimens were quantified at 550°C–650°C using glow discharge optical emission spectroscopy and electron probe microanalysis. Analytical transmission electron microscopy was used to compare the thin protective Cr-rich oxide formed on alloy 709 in sCO2 at 650°C to that formed in ambient air.
直接燃烧的超临界二氧化碳(sCO2)动力循环正在商业化，以彻底改变化石能源作为低排放的动力来源。为了降低这项技术的成本，在循环的较低温度部分需要更便宜的钢材。然而，人们担心在sCO2中钢的内部渗碳。一个一致的观察是，与9-12% Cr铁素体-马氏体钢上形成的厚的富铁氧化物相比，薄的富Cr氧化物似乎减少了C的进入。先进的奥氏体不锈钢(SS)，如709合金(20Cr-25Ni)能够在650°C下继续形成富cr氧化物，而传统的316 H SS形成富铁垢。在550°C - 650°C温度下，采用辉光放电光谱法和电子探针显微分析方法对SS样品中的C扩散谱进行定量分析。采用透射电镜分析方法，比较了709合金在650℃下在sCO2中形成的薄层富cr保护氧化物与在环境空气中形成的富cr保护氧化物。
{"title":"Internal carburization and scale formation on austenitic steels in supercritical carbon dioxide","authors":"B. Pint, Y. F. Su, M. Lance, R. Pillai, J. Keiser","doi":"10.1080/09603409.2023.2219875","DOIUrl":"https://doi.org/10.1080/09603409.2023.2219875","url":null,"abstract":"ABSTRACT Direct-fired supercritical CO2 (sCO2) power cycles are being commercialised to revolutionise fossil energy as a low-emission power source. To lower the cost of this technology, less expensive steels are needed in the lower temperature segments of the cycle. However, there are concerns about internal carburisation of steels in sCO2. 1 A consistent observation is that thin, Cr-rich oxides appear to reduce C ingress compared to thick Fe-rich oxides formed on 9–12% Cr ferritic-martensitic steels. Advanced austenitic stainless steels (SS) like alloy 709 (20Cr-25Ni) are able to continue to form Cr-rich oxides at 650°C, while a conventional type 316 H SS formed a Fe-rich scale. The C diffusion profiles in SS specimens were quantified at 550°C–650°C using glow discharge optical emission spectroscopy and electron probe microanalysis. Analytical transmission electron microscopy was used to compare the thin protective Cr-rich oxide formed on alloy 709 in sCO2 at 650°C to that formed in ambient air.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":"27 1","pages":"308 - 317"},"PeriodicalIF":1.3,"publicationDate":"2023-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81025771","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}
Pub Date : 2023-06-04DOI: 10.1080/09603409.2023.2219877
A. Potter, J. Sumner, N. Simms
ABSTRACT Gas turbine materials often feature precipitates containing refractory metals to enhance their mechanical strength. This can make them susceptible to alloy-induced acidic fluxing whereby refractory elements increase the acidity of salt deposits. It is not clear to what degree degradation around alloy precipitates is caused by alloy-induced hot corrosion mechanisms, or the inability to develop a protective scale where precipitates are located. The effect of alloy-induced hot corrosion was isolated from the disruption of the protective-scale formation by adding particles of molybdenum to the 80/20 (Na/K)2SO4 deposit for a ‘deposit re-coat’ style hot corrosion test. The resulting morphologies were compared to samples exposed without the addition of molybdenum. Morphology changes were investigated using scanning electron microscopy with energy-dispersive X-ray mapping. Results show a mix of sulphidation and pitting. The effects of molybdenum additions appear more severe for MarM 509 compared to PWA 1483.
{"title":"Further investigations into alloy induced acidic fluxing","authors":"A. Potter, J. Sumner, N. Simms","doi":"10.1080/09603409.2023.2219877","DOIUrl":"https://doi.org/10.1080/09603409.2023.2219877","url":null,"abstract":"ABSTRACT Gas turbine materials often feature precipitates containing refractory metals to enhance their mechanical strength. This can make them susceptible to alloy-induced acidic fluxing whereby refractory elements increase the acidity of salt deposits. It is not clear to what degree degradation around alloy precipitates is caused by alloy-induced hot corrosion mechanisms, or the inability to develop a protective scale where precipitates are located. The effect of alloy-induced hot corrosion was isolated from the disruption of the protective-scale formation by adding particles of molybdenum to the 80/20 (Na/K)2SO4 deposit for a ‘deposit re-coat’ style hot corrosion test. The resulting morphologies were compared to samples exposed without the addition of molybdenum. Morphology changes were investigated using scanning electron microscopy with energy-dispersive X-ray mapping. Results show a mix of sulphidation and pitting. The effects of molybdenum additions appear more severe for MarM 509 compared to PWA 1483.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":"209 1","pages":"338 - 347"},"PeriodicalIF":1.3,"publicationDate":"2023-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73127939","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}
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