Volume 6A: Materials and Fabrication最新文献

{"title":"Multi-Scale Damage Analysis on Fatigue-Creep Process in Industrial Steel Structures","authors":"Huajing Guo, Z. Li","doi":"10.1115/pvp2019-93982","DOIUrl":"https://doi.org/10.1115/pvp2019-93982","url":null,"abstract":"\u0000 Fatigue-creep damage has been recognized as the elemental cause of failure of industrial steel structures exposed to high temperature. In order to better understand the degradation process, a previously developed multi-scale fatigue-creep damage is applied to evaluate the structural damage due to fatigue and creep process. In the model, the relationship between collective behavior of micro-cracks and fatigue damage variable was established and the nonlinear coupling of fatigue damage and creep damage was taken into consideration. Fatigue-creep damage analysis on a series of existing key connection shafts in industrial steel structures at high temperature are performed under different working condition and their lifetime are predicted based on the numerical calculation on the accumulated fatigue-creep damage up to structural failure. The numerical results indicate that the early stage of degeneration process is dominated by creep damage and the fatigue damage rate increases quickly at the later stage. The fatigue-creep lifetime of industrial steel structures varies significantly with different applied stress level and working temperature.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116453525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Approach to Account for Weld Residual Stresses in Pressure Vessel Flaw Assessments","authors":"F. Brust, L. Hill, G. Wilkowski, Y. Hioe, K. Bagnoli","doi":"10.1115/pvp2019-94022","DOIUrl":"https://doi.org/10.1115/pvp2019-94022","url":null,"abstract":"\u0000 A periodic inspection of a reactor pressure vessel in refinery was scheduled. Prior to that inspection, criteria need to be established to determine what flaw indication would be tolerable so that the vessel can safely be put back in to service in a timely manner, or in the worst case, identify what flaw indication would create a very strong case for repair or replacement criteria for the vessel. A flaw tolerance criterion that can be applied to the refinery inspection process was developed for numerous potential flaw locations in this vessel. The finite element alternating method was used to determine the appropriate fracture parameters to assist in this flaw assessment procedure. These computational efforts involved examining the fracture response of the system in preparation for planned inspections.\u0000 Stress intensity factors were evaluated for a total of ten (10) cracks inserted into the refinery pressure vessel at several locations and crack orientations. Most of the cracks had depth to thickness ratios of 0.25 and a half width 3 times this depth. The crack sizes are chosen based on the assumed maximum initial flaw sizes expected to be found from NDI. The stress intensity factor for residual stress loading was conservatively estimated by placing a unit tensile pressure on the crack face for all 10 cracks. The approximation of crack face pressure loading to simulate residual stress is also shown to be accurate. Therefore, one can estimate the contribution to stress intensity factor by multiplying the residual stress value of K by the estimated residual stress ratio. The final estimate of crack driving force for a crack, KI, is obtained by adding the contributions of the pressure loading with the residual stress contribution. Internal pressure loading of this vessel is the only significant source of loading in this vessel.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"23 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113989315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"European Project ATLAS+: Evaluation of a Shear Modified Gurson Model by Comparison to Experimental Fracture Tests on SENT Fracture Specimens","authors":"Tobias Bolinder, D. Moinereau, P. L. Delliou, A. Dahl, J. Besson","doi":"10.1115/pvp2019-93620","DOIUrl":"https://doi.org/10.1115/pvp2019-93620","url":null,"abstract":"\u0000 This paper will assess the capability of the shear modified Gurson model developed by Nahshon and Hutchinson which is used by Kiwa Inspecta within the ATLAS+ project. This is done by comparison to experimental results from SENT fracture tests performed by EDF and ARMINES. The procedure for parameter identification for the standard and shear modified Gurson model is also summarized.\u0000 The work presented in this paper is part of Work Package 3 within the ATLAS+ project. WP3 focus mainly on ductile tearing predictions for large defects in components. Models exists to accurately predict ductile tearing and to consider phenomena such as stress triaxiality effects. These advanced models include local approach coupled models or advanced energetic approaches. However, there is a need to validate these models for use in industrial applications. This will be done within the ATLAS+ project by predicting the results of the large scale component tests where input to the models are given from small size laboratory specimens.\u0000 Within the paper a description of the shear modified Gurson model is given, as developed by Nashson and Hutchinson [1]. Furthermore, the procedure in determining the material model parameters is discussed. To determine the material parameters for the shear modified Gurson model a uniaxial tensile test, a fracture test and shear tests are used. The material that is used is the ferritic steel WB 36 (15 NiCuMoNb 5) which will be used for the large scale component tests within the ATLAS+ project. The procedure is also evaluated by comparing predictions done with the shear modified Gurson model to experimental results from SENT specimens performed by EDF and ARMINES.\u0000 A comparison of the capability in predicting the ductile tearing in the SENT experiments between the standard Gurson model and the shear modified Gurson model is also presented within the paper.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114833693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deformation Behavior and J-Integral of Macroscopic Hydride Platelet Clusters in Hydrided Zr-2.5Nb Pressure Tube Materials Under Plane Strain Conditions","authors":"Shengji Wu, Jwo Pan, D. Scarth, S. Lawrence","doi":"10.1115/pvp2019-93763","DOIUrl":"https://doi.org/10.1115/pvp2019-93763","url":null,"abstract":"\u0000 The mechanical behavior and J-integral of macroscopic hydride platelet clusters in hydrided Zr-2.5Nb pressure tube materials are investigated by two-dimensional finite element analyses with cohesive zone model under plane strain conditions. The hydride platelets are assumed to be separated at the early stage of the loading and are treated as cracks. The cohesive zone model with a trapezoidal traction-separation law is adopted. The macroscopic mechanical behavior is quantified by the macroscopic stress-strain relations and the fracture parameter of the bulk radial hydride is specified by the J integral-stress relations. The hydride platelet spacing has major effects while the cohesive energy and cohesive strength have minor effects on the mechanical behavior and fracture properties of the bulk hydrides. The computational results suggest that the hydride platelet cluster can be viewed as a soft region with a reduced load carrying capacity at large stress under plane strain loading conditions. A hydride platelet cluster may be treated as a cracked bulk hydride but with a reduced crack tip driving force for fracture.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128137134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the Fracture Toughness in Electron Beam Welds","authors":"M. Mokhtarishirazabad, C. Simpson, G. Horne, S. Kabra, C. Truman, A. Moffat, M. Mostafavi","doi":"10.1115/PVP2019-93655","DOIUrl":"https://doi.org/10.1115/PVP2019-93655","url":null,"abstract":"\u0000 High energy welding technologies, such as electron beam, have a number of potential benefits including: faster process time, smaller heat affected zone and potentially favourable weld residual stresses. Therefore, they are good candidates for manufacturing complex components for the next generation of nuclear power plants. However, before electron beam can be deployed on a wide scale, further work is required in a number of areas, including how these welds are treated in structural integrity assessments. As an example, the full extent of the effects of complex residual stress (RS) fields, arising from high energy welding technology, on the fracture behaviour of components has not been fully investigated. This understanding is essential for defect tolerance calculations using integrity assessment procedures. In this study, the fracture toughness of austenitic stainless steel 316L plates with various thicknesses (6mm to 25mm), joined by electron beam welding, is evaluated. Residual stresses were measured using non-destructive diffraction and mechanical relief methods (contour method). This is to examine the effect of welding residual stresses on the resistance of the welded component to fracture.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114634040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large Ranges in Power Piping Girth Weld Creep Rupture Lives","authors":"M. Cohn, Fatma G. Faham","doi":"10.1115/pvp2019-93931","DOIUrl":"https://doi.org/10.1115/pvp2019-93931","url":null,"abstract":"\u0000 Stress analysis evaluations of high energy piping systems operating in the creep range have revealed that each piping system has a large range of ASME B31.1 Code stresses. It is typical that there are only a few locations of high stresses and many more locations of much lower Code stresses. Over the past 20 years, the authors have evaluated several hundred piping systems operating in the creep range, including main steam, hot reheat, high pressure, and intermediate pressure systems constructed of Grade 11 (1¼-Cr-½Mo-Si), Grade 22 (2¼Cr-1Mo), and Grade 91 (9Cr-1Mo-V) materials. Stress contour plots illustrate the significant range of Code stresses (sometimes factors greater than 2) at various piping system locations. This study also considered the variation of high stress locations for the initial as-designed piping stress analysis versus the as-found stresses associated with field anomalies. The stress contour plots also illustrate that field anomalies in sister units can result in different high stress locations from one unit to another. In addition, significant unintended field anomalies may result in as-found analysis high stress locations at low stress as-designed (expected) analysis locations.\u0000 Since there is a large range of stresses in these power piping systems, the girth welds have a significant range of creep rupture lives. In Grade 11 material operating at 1000°F (538°C), an 18% stress increase results in 50% decrease in creep rupture life. In Grade 22 material operating at 1000°F, a 12% stress increase results in 50% decrease in creep rupture life. In Grade 91 material operating at 1060°F (571°C), an 8% stress increase results in 50% decrease in creep rupture life. For Grades 11, 22, and 91, the creep rupture times are a function of stress to the powers of 4, 6, and 9, respectively. Consequently, the evaluation of the large range of stresses in these piping systems revealed that the piping system girth welds can have creep rupture lives varying by more than a factor of 10. The large range of piping stresses and associated large range in creep rupture lives within a piping system are illustrated as stress histograms for several example piping systems. Four case studies illustrate successful selection of girth weldments with the most in-service related creep damage.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114914046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Irradiation Embrittlement of the Chinese RPV Steels","authors":"Yupeng Cao, Yinbiao He, Binxi Wang, Yifeng Huang, Hui Li, Yan Yu, H. Hui","doi":"10.1115/pvp2019-93615","DOIUrl":"https://doi.org/10.1115/pvp2019-93615","url":null,"abstract":"\u0000 Reactor pressure vessel (RPV) is considered to be irreplaceable, which is the most limiting factor for the lifetime of a nuclear power plant. This paper aims to introduce our project for the evaluation of the irradiation embrittlement for the Chinese RPV forging. The forging manufactured in China was irradiated in the high fluence engineering test reactor. Tensile tests, Charpy impact tests and fracture toughness tests in terms of master curve T0 were carried out for the material subjected to different irradiation fluences. Comparison of the mechanical properties of the irradiated materials and the materials without irradiation is made. The irradiation resistance of the materials in our project is also compared with the data for the irradiated RPV steels in the literatures.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124032849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Optimized Welding Consumable for Joining Type 410 Martensitic Stainless Steel","authors":"B. J. Lawson, B. Alexandrov, J. Bundy, D. Benson, J. Penso","doi":"10.1115/pvp2019-93682","DOIUrl":"https://doi.org/10.1115/pvp2019-93682","url":null,"abstract":"\u0000 Type 410 martensitic stainless steel is used in some downstream hydro-processing installations, due to its good resistance to sulfide corrosion and chloride stress corrosion cracking. Industry experience with Type 410 steel welds, using generic welding consumables, has shown difficulties in meeting the weld metal and HAZ hardness and toughness requirements. Recent research has pointed out the wide composition specifications of Type 410 base metal and welding consumables as the leading cause for significant hardness and toughness variations, related to exceeding the A1 temperature during PWHT and formation of fresh martensite, and to retention of significant amounts of delta ferrite. Predictive equations for the A1 temperature and the content of retained delta ferrite were used to identify optimal composition for Type 410 welding consumables with delta ferrite content below 20% and A1 temperature close to the upper end of the ASME specified PWHT range. Experimental metal core filler wire was manufactured and tested to validate the A1 temperature and delta ferrite content. A test weld in Type 410 steel was produced with the new filler wire and subjected to PWHT, metallurgical characterization, and mechanical testing. The weld metal and HAZ properties met the corresponding NACE and ASME hardness and toughness requirements.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128610949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crack Repair Using Hybrid Additive Manufacturing and Friction Stir Processing","authors":"F. Al-Badour, Ibrahim H. Zainelabdeen, R. Suleiman, A. Adesina","doi":"10.1115/pvp2019-93688","DOIUrl":"https://doi.org/10.1115/pvp2019-93688","url":null,"abstract":"\u0000 A hybrid additive manufacturing (AM) and friction stir processing (FSP) was used to heal a crack in 6 mm thick Al 6061-T6 aluminum alloy. AL-6061 is usually used in H2 high-pressure vessel fabrication as well as aerospace applications. In this work, Al-Si powder was utilized to fill the crack, then FSP was applied to consolidate and stir the powder with the base metal to fill and close the crack zone. Effect of FSP parameters including welding speed and tool rotation speed on the quality of repair was studied. Various mechanical tests, as well as characterization techniques such as hardness test, optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), were employed to study the newly developed hybrid process on the quality of the repair. The investigation revealed that low rotational speed of 800 rpm results in minimum variation in microhardness. Moreover, the impact of welding speed on microhardness is smaller as compared to rotational speed.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129103721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Constraint in Specimen Geometries When Evaluating Fracture Toughness/Material Fracture Resistance for a Surface-Flawed Elbow","authors":"S. Kalyanam, G. Wilkowski, F. Brust, Y. Hioe, E. Punch","doi":"10.1115/pvp2019-93732","DOIUrl":"https://doi.org/10.1115/pvp2019-93732","url":null,"abstract":"\u0000 The fracture behavior of a circumferential surface crack in an elbow was evaluated using past data from the International Piping Integrity Research Group (IPIRG-2) Experiment 2-4. The elbow tested was nominal 16-inch diameter Schedule 100 TP304 material, which was solution-annealed after final fabrication. The elbow was loaded with an in-plane-closing bending moment and internal pressure of 15.51 MPa (2,250 psig) at 288 C (550 F). The surface crack was 180-degrees on the ID surface and centered on the extrados, but after fatigue precracking the depth was variable and the greatest was at about 45-degrees from the extrados. FE analysis of the IPIRG-2 elbow test was conducted with a state-of-the-art and precise 3D FE mesh (including variable surface crack depth, variable thickness, and initial elbow ovalization). The flaw depth for the single-edge notch tension (SENT) tests was selected to be equivalent to the deepest point in the elbow specimen crack front that provided the largest J-value in the elbow experiment, i.e., ao/W = 0.68. Comparison of the J-value for initiation (Ji) and crack-tip-opening displacement (CTODi) at crack initiation suggested that there was a slight difference in constraint between an identical depth SENT specimen (a/W = 0.68 with the same L-R orientation as the surface crack in the pipe) and an elbow with a circumferential surface crack (a/t = 0.68) [Ji was 0.368 MN/m, (2.1 ksi-inch) in the SENT tests, while it was 0.490 MN-m (2.8 ksi-inch) in the elbow test]. The more significant finding in this work was that the compact tension (C(T)) test Ji-value was much higher at 1.086 MN/m (6.2 ksi-inch) or ∼3 times higher. The elbow to SENT to C(T) specimen comparison illustrates very large differences in constraint between these geometries. From past work by several researchers it was determined that the constraint in C(T) specimens gives Ji-values that agree well with a circumferential through-wall crack in a straight pipe, but this difference with surface-cracked elbow or pipe is envisaged to be new information to the international research community. Additionally, from state-of-the-art FE analysis of the 180-degree surface-cracked elbow test it was found that the maximum J-value occurs at a position that was about 45-degree away from the extrados location. This trend showed that caution should be exercised when selecting the crack locations for elbow integrity evaluation, since for shorter flaw lengths it may be more critical to consider a crack that is closer to the 45-degrees from the extrados, which could be true for fracture as well as stress corrosion cracking (SCC) elbow evaluations.","PeriodicalId":428760,"journal":{"name":"Volume 6A: Materials and Fabrication","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129204146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}