Thomas Bouchenot, Kirtan Patel, A. Gordon, S. Shinde
While industrial gas turbine blades are commonly designed to resist creep and high-cycle fatigue (HCF) failure, the combination of these two loading conditions is seldom considered. The effect of creep damage elicited prior or concurrent to HCF loading is not well established and can significantly reduce the HCF lifetime of these critical components. A comprehensive life prediction model capable of capturing these superimposed effects is needed to ensure current reliability standards are maintained when designing aggressively-loaded, next-generation industrial gas turbine blades. The consequence of combined HCF and creep loading to the lifetime a Ni-base superalloy is characterized and modeled in this study. Composition and calibration of the model is carried out using data from HCF tests conducted on virgin and pre-crept specimens at 750°C and 850°C. The experimental data encompasses a wide range of stress ratios and pre-creep strains to mimic to the expansive set of potential turbine blade loading conditions The proposed microstructurally-informed model is based on existing principles and relies on test data and information gathered from a comprehensive failure analysis of the tested samples.
{"title":"Creation of a Life Prediction Model for Combined High-Cycle Fatigue and Creep","authors":"Thomas Bouchenot, Kirtan Patel, A. Gordon, S. Shinde","doi":"10.1115/1.4054889","DOIUrl":"https://doi.org/10.1115/1.4054889","url":null,"abstract":"\u0000 While industrial gas turbine blades are commonly designed to resist creep and high-cycle fatigue (HCF) failure, the combination of these two loading conditions is seldom considered. The effect of creep damage elicited prior or concurrent to HCF loading is not well established and can significantly reduce the HCF lifetime of these critical components. A comprehensive life prediction model capable of capturing these superimposed effects is needed to ensure current reliability standards are maintained when designing aggressively-loaded, next-generation industrial gas turbine blades. The consequence of combined HCF and creep loading to the lifetime a Ni-base superalloy is characterized and modeled in this study. Composition and calibration of the model is carried out using data from HCF tests conducted on virgin and pre-crept specimens at 750°C and 850°C. The experimental data encompasses a wide range of stress ratios and pre-creep strains to mimic to the expansive set of potential turbine blade loading conditions The proposed microstructurally-informed model is based on existing principles and relies on test data and information gathered from a comprehensive failure analysis of the tested samples.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43614065","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}
A novel two-dimensional shear stress-heat and moisture diffusion model is proposed for adhesive single-lap-joints. Spatial and time-dependent material properties are derived from coupled partial differential equations governing moisture diffusion and heat transfer through the exposed adhesive edges. Constituting differential equations are numerically solved for the shear stress distribution in the bonded area. Several diffusion scenarios and boundary conditions are analyzed. Significant improvements are achieved in the prediction of the shear stress distribution in the adhesive layer, when compared to the one-dimensional models in the literature. Scenarios of moisture diffusion generate stress gradients through the bondline, while the relatively fast internal thermal conductivity reduces temperature differentials within the joint. Moisture diffusion in the adhesive layer is significantly accelerated at high temperature. The results of the proposed model show reasonable agreement with a three-dimensional Finite Elements Analysis.
{"title":"Novel Modeling of Heat and Moisture Diffusion in Adhesive Joints","authors":"Marco Gerini-Romagnoli, S. Nassar","doi":"10.1115/1.4054828","DOIUrl":"https://doi.org/10.1115/1.4054828","url":null,"abstract":"\u0000 A novel two-dimensional shear stress-heat and moisture diffusion model is proposed for adhesive single-lap-joints. Spatial and time-dependent material properties are derived from coupled partial differential equations governing moisture diffusion and heat transfer through the exposed adhesive edges. Constituting differential equations are numerically solved for the shear stress distribution in the bonded area. Several diffusion scenarios and boundary conditions are analyzed. Significant improvements are achieved in the prediction of the shear stress distribution in the adhesive layer, when compared to the one-dimensional models in the literature. Scenarios of moisture diffusion generate stress gradients through the bondline, while the relatively fast internal thermal conductivity reduces temperature differentials within the joint. Moisture diffusion in the adhesive layer is significantly accelerated at high temperature. The results of the proposed model show reasonable agreement with a three-dimensional Finite Elements Analysis.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45037792","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}
Jean-Baptiste Le Bail, B. Levieil, S. Moyne, C. Doudard, S. Calloch
The adjustable localization operator method allows for the local analytical calculation of complex structures under multiaxial confined plasticity cyclic loadings. This study proposes a theoretical framework for the extension of the method to cover anisotropic yield surface materials. The application is carried out on steel tubes that have been axially compressed beforehand to create a bead that acts as a stress concentration factor during the fatigue loading process. The adjustable localization operator method is compared to the reference finite element anisotropic analysis at different steps of the fatigue design chain. Results have shown that, although a slight gap on the absolute strain values exists, the strain amplitude and thus the fatigue life are correctly predicted with a reduction of the calculation time by 100.
{"title":"Extension of the Adjustable Localization Operator Method to Anisotropic Elasto-Plastic Behaviour for Low-Cycle Fatigue Life Prediction","authors":"Jean-Baptiste Le Bail, B. Levieil, S. Moyne, C. Doudard, S. Calloch","doi":"10.1115/1.4054289","DOIUrl":"https://doi.org/10.1115/1.4054289","url":null,"abstract":"\u0000 The adjustable localization operator method allows for the local analytical calculation of complex structures under multiaxial confined plasticity cyclic loadings. This study proposes a theoretical framework for the extension of the method to cover anisotropic yield surface materials. The application is carried out on steel tubes that have been axially compressed beforehand to create a bead that acts as a stress concentration factor during the fatigue loading process. The adjustable localization operator method is compared to the reference finite element anisotropic analysis at different steps of the fatigue design chain. Results have shown that, although a slight gap on the absolute strain values exists, the strain amplitude and thus the fatigue life are correctly predicted with a reduction of the calculation time by 100.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43958451","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}
Single-crystal (SC) nickel-based superalloy castings offer high temperature mechanical properties that result in superior gas turbine engine performance and durability. These castings undergo various precision machining operations to remove a significant amount of material while manufacturing. Here, nickel-based superalloys are one of the most difficult materials to be cut. Therefore, novel concepts are being employed to improve their machinability including lowering their surface strength. This paper presents the introduction of laser-induced surface damage (LISD) on a second-generation SC nickel-based superalloy using a CW (continuous wave) fiber laser. Laser scanning experiments were performed on SC specimens in as-cast condition with a laser power of 1000 W, beam diameter of 1.2 mm and scanning speeds from 5.5 mm/s to 16.5 mm/s. The cross-sections of the laser irradiated surfaces were investigated by measuring the irradiated geometries (IRG), micro-structural changes, micro-segregations, solidification cracking and heat affected zone (HAZ). The IRG shows conduction mode of penetration with a high width-to-depth ratio under a bigger beam diameter and top-hat type beam profile. The IRG boundaries have irregular profiles due to the dissolution of inter-dendrite regions and eutectic phases. The IRG showed fine dendrites and solidification cracks with reduced micro-segregation levels. The solidification cracking is mainly attributed to thermal stresses and the micro-cracking in HAZ is attributed to the dissolution of low melting Mo and Ti eutectics. The evolved HAZ ranges from 15 to 20 % of the IRG depth. The LISD volume is evaluated as IRG plus HAZ for removal by machining process.
{"title":"Experimental Study on Laser-Induced Surface Damage of a Single-Crystal Nickelbased Superalloy under CW Fiber Laser Scanning Process","authors":"S. Nandam, A. Rao, A. Gokhale, S. Joshi","doi":"10.1115/1.4054228","DOIUrl":"https://doi.org/10.1115/1.4054228","url":null,"abstract":"\u0000 Single-crystal (SC) nickel-based superalloy castings offer high temperature mechanical properties that result in superior gas turbine engine performance and durability. These castings undergo various precision machining operations to remove a significant amount of material while manufacturing. Here, nickel-based superalloys are one of the most difficult materials to be cut. Therefore, novel concepts are being employed to improve their machinability including lowering their surface strength. This paper presents the introduction of laser-induced surface damage (LISD) on a second-generation SC nickel-based superalloy using a CW (continuous wave) fiber laser. Laser scanning experiments were performed on SC specimens in as-cast condition with a laser power of 1000 W, beam diameter of 1.2 mm and scanning speeds from 5.5 mm/s to 16.5 mm/s. The cross-sections of the laser irradiated surfaces were investigated by measuring the irradiated geometries (IRG), micro-structural changes, micro-segregations, solidification cracking and heat affected zone (HAZ). The IRG shows conduction mode of penetration with a high width-to-depth ratio under a bigger beam diameter and top-hat type beam profile. The IRG boundaries have irregular profiles due to the dissolution of inter-dendrite regions and eutectic phases. The IRG showed fine dendrites and solidification cracks with reduced micro-segregation levels. The solidification cracking is mainly attributed to thermal stresses and the micro-cracking in HAZ is attributed to the dissolution of low melting Mo and Ti eutectics. The evolved HAZ ranges from 15 to 20 % of the IRG depth. The LISD volume is evaluated as IRG plus HAZ for removal by machining process.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44127477","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}
M. J. Mills, Jacob Biddlecom, B. Piñeyro, T. Khraishi, S. Grutzik, A. Brink, M. Brake, K. Johnson
Fe-Co-2V (Hiperco equivalent) is a soft ferromagnetic material that is commonly used for electrical components that require robust magnetic performance. Despite the excellent magnetic properties of Fe-Co-2V, it often exhibits low strength, ductility, and workability due to an ordered B2 microstructure. The mechanical properties exhibit considerable dependency on grain size and degree of order, which are influenced by processing methods. A thorough understanding of Fe-Co-2V’s fatigue performance is required to predict mechanical reliability under operating loads; however, limited fatigue data currently exists for Fe-Co alloys. This work characterizes the fatigue properties of wrought Fe-Co-2V through strain-controlled fatigue testing and fractography. Young’s Modulus, ultimate strength, and yield stress were determined through monotonic tension tests. The fatigue behavior was quantified using fully reversed, strain-controlled fatigue testing for applied strain amplitudes ranging from 0.10% to 1.00%. Subsequently, the Coffin-Manson strain-life curve was fit to the experimental data. Failure mechanisms were investigated through fractography with a scanning electron microscope. Inspection of the failure surfaces revealed that crack initiation occurred at defects located on or near the specimen surface with a localized region of crack propagation prior to the transgranular cleavage fracture. Additionally, two material models were calibrated from the experimental static and cyclic experimental testing. The characterization of the fatigue behavior of wrought Fe-Co-2V presented herein will aid in the fatigue analysis of Fe-Co-2V components and the development of analytical fatigue modelling methodologies.
{"title":"Characterizing the Fatigue Behavior of Wrought Fe-Co-2V using Experimental Techniques","authors":"M. J. Mills, Jacob Biddlecom, B. Piñeyro, T. Khraishi, S. Grutzik, A. Brink, M. Brake, K. Johnson","doi":"10.1115/1.4054142","DOIUrl":"https://doi.org/10.1115/1.4054142","url":null,"abstract":"\u0000 Fe-Co-2V (Hiperco equivalent) is a soft ferromagnetic material that is commonly used for electrical components that require robust magnetic performance. Despite the excellent magnetic properties of Fe-Co-2V, it often exhibits low strength, ductility, and workability due to an ordered B2 microstructure. The mechanical properties exhibit considerable dependency on grain size and degree of order, which are influenced by processing methods. A thorough understanding of Fe-Co-2V’s fatigue performance is required to predict mechanical reliability under operating loads; however, limited fatigue data currently exists for Fe-Co alloys. This work characterizes the fatigue properties of wrought Fe-Co-2V through strain-controlled fatigue testing and fractography. Young’s Modulus, ultimate strength, and yield stress were determined through monotonic tension tests. The fatigue behavior was quantified using fully reversed, strain-controlled fatigue testing for applied strain amplitudes ranging from 0.10% to 1.00%. Subsequently, the Coffin-Manson strain-life curve was fit to the experimental data. Failure mechanisms were investigated through fractography with a scanning electron microscope. Inspection of the failure surfaces revealed that crack initiation occurred at defects located on or near the specimen surface with a localized region of crack propagation prior to the transgranular cleavage fracture. Additionally, two material models were calibrated from the experimental static and cyclic experimental testing. The characterization of the fatigue behavior of wrought Fe-Co-2V presented herein will aid in the fatigue analysis of Fe-Co-2V components and the development of analytical fatigue modelling methodologies.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45393758","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}
In this present study, both the experimental and numerical investigations are carried out to understand the formability of 1.5 mm thick AA 5052-H32 sheets with friction stir spot weld (FSSW). A shock tube experimental facility is utilized in which a rigid hemispherical striker is propelled at a high velocity and deforms the FSSW sheets at high strain rates. In this analysis, the effect of different tool rotational speed and plunge depth on the FS spot welding outputs and forming outputs are understood. Furthermore, DEFORM-3D FE code is used to perform FE simulation of both the FS spot welding and forming of the welded sheets interactively. During FE simulation of impact forming, tensile data obtained from the unwelded section of the sheet deformed using the shock tube is fit to modified Johnson-Cook (MJC) model. In the case of the FS spot welded region, a hardness based multiplying factor is identified and used to obtain stress-strain data by fitting to MJC model. The predicted temperature evolution during the FSSW is validated with the experimental data and a good correlation has been observed. The predicted material flow phenomenon gives an insight about the joint formation during FSSW. Various forming outputs such as deformation profile, failure pattern and effective strain distribution predicted by MJC model in combination with Freudenthal damage model is compared with the experimental data and the results have a fair agreement.
{"title":"Impact Forming of AA5052-H32 Sheets with Friction Stir Spot Welds Using a Shock Tube and Failure Assessment","authors":"S. K. Barik, Ganesh R Narayanan, N. Sahoo","doi":"10.1115/1.4053894","DOIUrl":"https://doi.org/10.1115/1.4053894","url":null,"abstract":"\u0000 In this present study, both the experimental and numerical investigations are carried out to understand the formability of 1.5 mm thick AA 5052-H32 sheets with friction stir spot weld (FSSW). A shock tube experimental facility is utilized in which a rigid hemispherical striker is propelled at a high velocity and deforms the FSSW sheets at high strain rates. In this analysis, the effect of different tool rotational speed and plunge depth on the FS spot welding outputs and forming outputs are understood. Furthermore, DEFORM-3D FE code is used to perform FE simulation of both the FS spot welding and forming of the welded sheets interactively. During FE simulation of impact forming, tensile data obtained from the unwelded section of the sheet deformed using the shock tube is fit to modified Johnson-Cook (MJC) model. In the case of the FS spot welded region, a hardness based multiplying factor is identified and used to obtain stress-strain data by fitting to MJC model. The predicted temperature evolution during the FSSW is validated with the experimental data and a good correlation has been observed. The predicted material flow phenomenon gives an insight about the joint formation during FSSW. Various forming outputs such as deformation profile, failure pattern and effective strain distribution predicted by MJC model in combination with Freudenthal damage model is compared with the experimental data and the results have a fair agreement.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46960253","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}
H. Salem, Peter Ibrahim, Moataz M. Attallah, H. Salem
Post-processing of Ti6Al4V lattice structures fabricated using selective laser melting (SLM) was performed using hot isostatic pressing (HIPing) and heat treatment (HT) to mitigate the undesired effect of rapid cooling during SLM. Oxygen diffusion during post-processing had a significant influence on the microstructure and subsequently the mechanical properties of the lattices. Oxygen content analysis was conducted to confirm the oxygen diffusion through the strurts' peripheries. The effect of oxygen diffusion during the HIPing and sub-transus HT (600-800 °C) regimes on the phase transformation, failure mechanisms and mechanical properties of the lattices was investigated. Results revealed that the transformation of the originally formed α' martensite was dependent on the post-processing temperature. This transformation resulted in a decrease in yield strength. The decrease in failure strain (ductility) for all treated conditions was related to oxygen diffusion, forming near-surface α-case.
{"title":"Effect of Oxygen Diffusion During the Post-Processing Of Ti6Al4V Lattice Structures Fabricated by the SLM Process","authors":"H. Salem, Peter Ibrahim, Moataz M. Attallah, H. Salem","doi":"10.1115/1.4053870","DOIUrl":"https://doi.org/10.1115/1.4053870","url":null,"abstract":"\u0000 Post-processing of Ti6Al4V lattice structures fabricated using selective laser melting (SLM) was performed using hot isostatic pressing (HIPing) and heat treatment (HT) to mitigate the undesired effect of rapid cooling during SLM. Oxygen diffusion during post-processing had a significant influence on the microstructure and subsequently the mechanical properties of the lattices. Oxygen content analysis was conducted to confirm the oxygen diffusion through the strurts' peripheries. The effect of oxygen diffusion during the HIPing and sub-transus HT (600-800 °C) regimes on the phase transformation, failure mechanisms and mechanical properties of the lattices was investigated. Results revealed that the transformation of the originally formed α' martensite was dependent on the post-processing temperature. This transformation resulted in a decrease in yield strength. The decrease in failure strain (ductility) for all treated conditions was related to oxygen diffusion, forming near-surface α-case.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41727683","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}
M. Jianfeng, Jianwei Zhu, Dasheng Wang, Fengping Zhong, Chen Jichang, Zhou Qiang, Bao Shiyi
In this paper, P92 steel was subjected to thermal ageing treatment at 650°C for 800h, and then basic mechanical and creep-fatigue In this paper, P92 steel was subjected to thermal ageing treatment at 650°C for 800h, and then basic mechanical and creep-fatigue test were performed. The creep-fatigue cycle response trend is consistent before and after ageing. Subsequently, microscopic observation shows that P92 steel after ageing still has typical lamellar martensite and prior austenite grains. The thermal ageing of 650°C resulted in more precipitates of martensite lath, obvious lath boundary, coarsening of martensite lath and decreased dislocation density. Furthermore, thermal ageing results in the increase of precipitates (Laves phase) and martensite width of P92 steel. The fine Laves phase located on the grain boundary can effectively nail the grain boundary, and play the role of precipitation strengthening. Besides, the Laves phase located on the dislocation has the effect of diffusion strengthening, which prevents dislocation slip and improves the creep-fatigue resistance of P92 steel. Finally, four creep-fatigue life model parameters of ageing P92 steel were obtained according to the test, including strain range partitioning (SRP), strain energy partitioning (SEP), frequency separation life model (FSL) and strain energy density exhaustion model (SEDE). The prediction results of the four models all fall within the double tolerance zone. The SPR and SEP are found to be conservative, while the FSL and SEDE are recommended herein due to their suitability of predicting creep-fatigue life of aging P92 steel.
{"title":"Influence of 650°C Thermal Ageing on Microstructure and Creep-Fatigue Behaviors of P92 Steel","authors":"M. Jianfeng, Jianwei Zhu, Dasheng Wang, Fengping Zhong, Chen Jichang, Zhou Qiang, Bao Shiyi","doi":"10.1115/1.4053772","DOIUrl":"https://doi.org/10.1115/1.4053772","url":null,"abstract":"\u0000 In this paper, P92 steel was subjected to thermal ageing treatment at 650°C for 800h, and then basic mechanical and creep-fatigue In this paper, P92 steel was subjected to thermal ageing treatment at 650°C for 800h, and then basic mechanical and creep-fatigue test were performed. The creep-fatigue cycle response trend is consistent before and after ageing. Subsequently, microscopic observation shows that P92 steel after ageing still has typical lamellar martensite and prior austenite grains. The thermal ageing of 650°C resulted in more precipitates of martensite lath, obvious lath boundary, coarsening of martensite lath and decreased dislocation density. Furthermore, thermal ageing results in the increase of precipitates (Laves phase) and martensite width of P92 steel. The fine Laves phase located on the grain boundary can effectively nail the grain boundary, and play the role of precipitation strengthening. Besides, the Laves phase located on the dislocation has the effect of diffusion strengthening, which prevents dislocation slip and improves the creep-fatigue resistance of P92 steel. Finally, four creep-fatigue life model parameters of ageing P92 steel were obtained according to the test, including strain range partitioning (SRP), strain energy partitioning (SEP), frequency separation life model (FSL) and strain energy density exhaustion model (SEDE). The prediction results of the four models all fall within the double tolerance zone. The SPR and SEP are found to be conservative, while the FSL and SEDE are recommended herein due to their suitability of predicting creep-fatigue life of aging P92 steel.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49388455","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}
To scrupulously predict the creep-fatigue life of materials, a creep life prediction model is firstly proposed in this study considering real-time creep damage derived from the Kachanov creep damage model; secondly, combined with the Chaboche fatigue damage model and the nonlinear coupling mechanism of continuous damage mechanics, a creep-fatigue life prediction model of material is ulteriorly presented in this paper; finally, the effectiveness of the creep-fatigue life model is corroborated by experiment data of DZ125, whose prediction results are in the ±2.0 dispersion zone and then the creep-fatigue life of the turbine blade is calculated to compare with the experimental results of the blade specimen to further prove the practicability, whose error is about 3.2%, which can provide a theoretical reference for the damage prediction, durability analysis, and life prediction of the turbine blade.
{"title":"Experimental and Numerical Study of Turbine Blade Fatigue Based on a Creep-fatigue Prediction Model","authors":"Debin Sun, J. Huo, Shaoxia An","doi":"10.1115/1.4053617","DOIUrl":"https://doi.org/10.1115/1.4053617","url":null,"abstract":"\u0000 To scrupulously predict the creep-fatigue life of materials, a creep life prediction model is firstly proposed in this study considering real-time creep damage derived from the Kachanov creep damage model; secondly, combined with the Chaboche fatigue damage model and the nonlinear coupling mechanism of continuous damage mechanics, a creep-fatigue life prediction model of material is ulteriorly presented in this paper; finally, the effectiveness of the creep-fatigue life model is corroborated by experiment data of DZ125, whose prediction results are in the ±2.0 dispersion zone and then the creep-fatigue life of the turbine blade is calculated to compare with the experimental results of the blade specimen to further prove the practicability, whose error is about 3.2%, which can provide a theoretical reference for the damage prediction, durability analysis, and life prediction of the turbine blade.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44361041","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":"Dislocation Mechanics of Extremely High Rate Deformations in Iron and Tantalum","authors":"M. Shehadeh, P. Ters, R. Armstrong, W. Arnold","doi":"10.1115/1.4052104","DOIUrl":"https://doi.org/10.1115/1.4052104","url":null,"abstract":"","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"308 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76340738","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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