Materials at High Temperatures最新文献

{"title":"Experience of P93 manifold welding under fabrication conditions","authors":"Patric de Smet, Koon-ging Tang, Michael Bok","doi":"10.1080/09603409.2023.2175293","DOIUrl":"https://doi.org/10.1080/09603409.2023.2175293","url":null,"abstract":"ABSTRACT A test manifold of grade P93 is welded under shop fabrication conditions. Raw materials include pipe and forgings. Welding processes used are GTAW and SMAW. Weld joints involve heavy wall butt welds and branch joints. Welded joints are subjected to different heat treatment cycles to assess the effect on the materials’ properties. Welding experiences and mechanical test results in relation to PWHT and ageing are discussed. Tensile test results comply with the requirements. Achieving impact toughness requirements appears to be challenging, however improvements are expected through further optimisation of heat treatment and welding procedures.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81453129","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":"High temperature component integrity in turbines required for flexible operation – evaluating assessment effectiveness","authors":"S. Holdsworth","doi":"10.1080/09603409.2023.2173717","DOIUrl":"https://doi.org/10.1080/09603409.2023.2173717","url":null,"abstract":"ABSTRACT In recent years, there has increasingly been the requirement for turbine generators to operate more efficiently, and in a more flexible way. Traditionally, the effectiveness of assessment procedures used to predict component integrity has been established on the basis of service experience. As the demand has increased for new materials to be adopted after increasingly shorter development periods, and more efficient and flexible operation to complement the availability of renewable energies has become the norm, it has no longer been possible to evaluate assessment effectiveness on the basis of prior operating experience, since it did not exist. The solution has been to use the results of component-feature specimen tests. Initially, these were full section isothermal benchmark tests conducted at the maximum operating temperature. Now the verification of assessment effectiveness using component-feature specimen, service-cycle TMF testing has become more realistic and economically viable, with (i) component-feature specimens of a more conventional laboratory testing size, but meeting prior defined geometry and damage mechanism requirements, and (ii) service-cycle details based on the results of operation-based non-linear (elastic-plastic-creep) finite element analysis.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86015975","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-fatigue defect development and risk of brittle fracture in the ultrasupercritical steam turbine rotors","authors":"M. Banaszkiewicz, J. Badur","doi":"10.1080/09603409.2022.2160896","DOIUrl":"https://doi.org/10.1080/09603409.2022.2160896","url":null,"abstract":"ABSTRACT The paper presents a critical analysis of the procedures for defect propagation assessment recommended by British standards and their application to rotating components. The way of applying these procedures was shown by an example of a steam turbine rotor with particular use of a characteristic strain model of high-temperature creep. Calculations of the flaws located at the rotor axis have shown that their growth in the design life is small. The performed analyses have also shown that crack development due to low-cycle fatigue is comparable to that due to creep and cannot be ignored under typical service condition. It was also shown that there is no risk of brittle fracture in the rotor under typical start-up conditions. The presented results prove the usefulness of the methods included in the British standards and guidelines for crack growth assessment in components subject to centrifugal load.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82582353","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":"Analysis of thermal stresses synergy in surface layer of carburised creep-resistant casts during rapid cooling processes","authors":"A. Bajwoluk, P. Gutowski","doi":"10.1080/09603409.2022.2162684","DOIUrl":"https://doi.org/10.1080/09603409.2022.2162684","url":null,"abstract":"ABSTRACT During the carburising processes, treated elements are transported on a specially designed technological equipment of the furnaces. This equipment works in particularly hard conditions. This is because in each work cycle, apart from the load carried by the charge, it is subjected to harmful effect of many other factors such as the highly carburising technical atmosphere of the furnace and high and rapidly changing temperature. These factors influence fatigue changes in the equipment’s parts, the observable effect of which may be cracks on the surface, propagating deeper into the material in subsequent cycles. A pivotal factor influencing the kinetics of fatigue processes in the carburising furnaces equipment are thermal stresses appearing in each operating cycle, with each temperature change. The thermal stresses in this equipment are caused by the temperature gradient across the section of the heated or cooled element and different thermal expansion of the structural components of the carburised alloy. In the paper, on the developed FEM model of the subsurface layer of a carburised rib of a pallet for transporting the charge in the furnace, analyses of stress distributions during rapid cooling were carried out. These analyses were performed with taking into account the separate impact of the above-mentioned sources of thermal stresses and their simultaneous action. In the analyses which consider the influence of the temperature gradient, the main load factor was the temperature distribution determined on the basis of the heat flow analyses carried out for the analysed section of pallets rib. The conducted analyses made it possible to assess the impact of local stresses caused by different thermal expansion of structural components of the carburised alloy on the change in the distribution of global stresses caused by the temperature gradient formed during rapid cooling. Based on the obtained results, it was assessed how the increased concentration of carbide precipitates, characteristic for the grain boundary of the carburised alloy, favours the formation of cracks observed in real castings, and whether the analysed stress sources have a significant impact on the kinetics of fatigue processes.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79401150","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":"Comparative study of Y2O3, SnO2 and ZrO2 as inhibitor to control high temperature corrosion of Ni-based superalloy","authors":"Gitanjaly Goyal, N. Bala, H. Singh, S. Prakash","doi":"10.1080/09603409.2023.2171546","DOIUrl":"https://doi.org/10.1080/09603409.2023.2171546","url":null,"abstract":"ABSTRACT High temperature corrosion of metals and alloys can be controlled by the use of inhibitors and fuel additives. In this work three different types of coatings namely Y2O3, SnO2 and ZrO2 coatings were superficially applied on Ni base superalloy Superni 718. Accelerated corrosion testing of the uncoated as well as the coated superalloy was done in a molten salt environment (Na2SO4-60%V2O5) at 900°C for 50 cycles. Each cycle consisted of 1 hour heating in a Silicon Carbide Tube furnace followed by 20 minutes cooling in ambient air. Weight change measurements after each cycle were taken by an electronic balance having an accuracy of 0.01 mg. XRD, SEM and EPMA analyses of the exposed specimens were carried out to characterise the oxide scales. The bare superalloy showed more overall weight gain, in comparison with all the coated counterparts. It was concluded that ZrO2 was most effective in reducing corrosion rate in alloy A.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85266939","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":"High-temperature corrosion data and mechanisms for T122, Super304H and HR3C after 15 years in 1000MW ultra-supercritical power plant","authors":"Haomin Wu, Shuo Wang, Qinxin Zhao, Z. Liang","doi":"10.1080/09603409.2023.2175156","DOIUrl":"https://doi.org/10.1080/09603409.2023.2175156","url":null,"abstract":"ABSTRACT The high-temperature corrosion of heat-resistant steels T122, Super304H and HR3C used for the inlet of a header in a 1000 MW ultra-supercritical power plant for 15 years was investigated. The steam temperature and pressure were about 610 °C and 28 MPa, respectively. The morphology and phase compositions of the corrosion products formed on the investigated tubes were analysed using X-ray diffraction and a scanning electron microscope with an energy dispersive spectroscopy detector. The results showed that the thickness of the corrosion products on the tube fireside was larger than that on the steam-side of the investigated tubes, which was due to the sulphur in the flue gas. The thickness rank of the corrosion products on the investigated steels was T122 > Super304H > HR3C. Defects including micro-cracks and voids were found in the corrosion products on both sides of the three tubes, which led to the breakaway of corrosion products.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90992435","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 unified constitutive approach for creep response of AISI 316 steel produced by conventional technologies or additive manufacturing techniques","authors":"S. Spigarelli","doi":"10.1080/09603409.2022.2146309","DOIUrl":"https://doi.org/10.1080/09603409.2022.2146309","url":null,"abstract":"ABSTRACT The creep response of AISI 316 and AISI 316 L was analysed to provide a coherent picture of the material behaviour, valid for both conventional wrought and additively manufactured steels. Literature evidences were considered. The analysis demonstrated that the presence of a fine distribution of particles, precipitated during creep exposure in both AISI 316 and 316 L(N), should be taken into account. A recent model, expressly developed for particle-strengthened alloys, was successfully used to describe the minimum creep rate dependence on applied stress for AISI 316 and 316 L(N). The same set of constitutive equations, in combination with the composite model, was then used for describing creep data obtained by testing the AISI 316 L produced by additive manufacturing. The main difference with wrought materials was that the microstructure of the additively manufactured alloy was composed by cells (soft zones) and thick walls heavily decorated with ultrafine oxide particles (hard zones).","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86504998","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":"Influence of deposit formation on corrosion at the high-temperature superheater of eucalyptus-fired boiler","authors":"Yuwei Wei, Yunkun Kuang, Guo-Li Li, Weichao Li, Weichong Chen, Jianxiong Han, Kun Zhang, Lin Zhu, Yongjun Li","doi":"10.1080/09603409.2022.2146315","DOIUrl":"https://doi.org/10.1080/09603409.2022.2146315","url":null,"abstract":"ABSTRACT Eucalyptus biomass-fired boilers generally experience severe problems with deposit formation and are expected to suffer from severe superheater corrosion at high temperatures due to the large alkali and chlorine content in eucalyptus biomass. The unique deposition layer structure and corrosion mechanism of eucalyptus-fired boilers are discussed in this paper. It was found that a unique sandwich like cell-membrane structure on the heating surface was formed in eucalyptus biomass-fired boilers. Chlorine acts as a catalyst, circulates the reaction and causes serious corrosion. The oxides at the junction of the corrosion layer and the matrix mainly penetrate along the grain boundary of the matrix, forming a unique network structure. There is obvious internal oxidation and mass transfer along the grain boundary in the matrix of 12Cr2MoWVTiB steel pipe, and no obvious internal oxidation in SA213T91 steel pipe due to its fine and uniform grains.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81790235","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":"New approaches to determine negligible creep","authors":"G. Baylac, C. Bullough, S. Holmström, W. Smith, A. Tonti, C. Forot","doi":"10.1080/09603409.2022.2135735","DOIUrl":"https://doi.org/10.1080/09603409.2022.2135735","url":null,"abstract":"ABSTRACT A CEN technical report has been drafted by working group WG59 CEN/TC54 on how to determine no- and negligible creep temperature limits to support EN 13445-3 (Unfired Pressure Vessels - Part 3: Design). Presently the standard assumes “rule-of-thumb” values for no-creep temperatures of ferritic and austenitic steels, 375°C and 425°C correspondingly. It is thought well known that the lower ferritic grades could be creeping below the limit temperature and creep strength enhanced ferritic steels may show significant creep at temperatures well beyond it. Similarly, austenitic steels; nickel and other alloys are likely to have an even wider range of limit temperatures. This paper describes the data assessments and test methods used to determine limit temperatures for a specific set of steels and comparisons are made to other standards and nuclear design codes. The new approaches promote iso-stress testing in the low temperature range and apply Wilshire equation assessments on historical data.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83474302","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":"Fireside corrosion and deposition on heat exchangers in biomass combustion systems","authors":"S. Mori, T. Sanusi, N. Simms, J. Sumner","doi":"10.1080/09603409.2022.2138007","DOIUrl":"https://doi.org/10.1080/09603409.2022.2138007","url":null,"abstract":"ABSTRACT To address climate change, power plants need to switch to greener fuels. One possible fuel is biomass; a carbon neutral/low carbon fuel. However biomasses’ chemistries are both different from coal’s and vary depending on their sources, containing unique levels of the trace elements (e.g., Cl and S) capable of altering the degradation of heat-exchangers. As such, an understanding of the effects of these variations on fireside corrosion is needed. Laboratory testing exposed alloys T91 and TP347HFG in a simulated agricultural product combustion environment at 600°C (up to 1000h; 100h cycles). Three different deposits mixtures were investigated (comprised of KCl, K2SO4, Na2SO4, CaSO4 indifferent percentages) mimicking accelerated corrosion from different biomasses. Corrosion behaviour was found to be dependant on both alloy and deposit chemistries, with the two materials showing different responses. The deposit with lowest KCl showed lowest corrosion damage, while the highest KCl deposit showed more aggressive behaviour.","PeriodicalId":49877,"journal":{"name":"Materials at High Temperatures","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73511167","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}