Journal of Pressure Vessel Technology (3)
Journal of Engineering Materials and Technology (2)
Journal of Engineering for Gas Turbines and Power (2)
Journal of Fluids Engineering (2)
Closures (1)
Pressure Vessels and Piping Conference (2)
Codes and Standards (3)
Discussions and Closures (1)
Gas Turbines: Industrial (1)
Gas Turbines: Vehicular and Small Turbomachines (1)
Creep (6)
Rupture (4)
Failure (3)
High temperature (3)
ASME Standards (2)
R. W. Swindeman
Technical Background for Alloy 617 Time Dependent Allowable Stresses
J. K. Wright, N. J. Lybeck, R. W. Swindeman, R. I. Jetter, T.-L. Sham, R. N. Wright
Proc. ASME. PVP2017, Volume 1B: Codes and Standards, V01BT01A020, July 16–20, 2017
Alloy 617 (UNS N06617) 52Ni-22Cr-13Co-9Mo is the leading candidate material for the intermediate heat exchanger for the very high temperature reactor (VHTR). An ASME Task Group on Alloy 617 Qualification has drafted a Code Case for Alloy 617 to allow construction of components conforming to the requirements of Section III, Division 5, Subsection HB, Subpart B "Elevated Temperature Service" for service when Service Loading temperatures exceed the temperature limits established in Subsection HB, Subpart A. There are two categories of allowable stress levels in Division 5, Subsection HB, Subpart B. The first category, identified as S o , applies to Design Loadings and the second category, identified as S mt , applies to Service Loadings. Both categories are based on the lesser of time dependent and time independent properties. The time dependent properties control at higher temperatures where creep effects are significant. The Design condition time-independent allowable stresses are determined per the criteria given in Appendix 5 of Section II, Part D and are based on extrapolated 100,000-hour creep properties. The time dependent allowable stress values for Service Loadings, S t , as a function of time and temperature, up to the maximum design lifetime and use temperature, are required for the applications of the Service condition limits. The criteria for establishing S t for base metal for each specified time, t , are based on the lesser of 1. 100% of the average stress required to obtain 1% total strain 2. 80% of the minimum stress to cause the initiation of tertiary creep, 67% of the minimum stress to cause rupture 3. Minimum stress-to-rupture curves are also required in the applications of the Service condition limits. In this paper, the technical background for time dependent allowable stress values for Alloy 617 is presented. These values are being recommended to the ASME Code committees for approval, but are subject to change upon feedback from Code committees.
Topics: Alloys, Stress, Temperature, Creep, Design, Rupture, Very high temperature reactors, ASME Standards, Base metals, Construction
Erratum: "Application of Negligible Creep Criteria to Candidate Materials for HTGR Pressure Vessel" ( Journal of Pressure Vessel Technology, 2011, 133, p. 021103 )
R. I. Jetter, T.-L. Sham, R. W. Swindeman
Journal: Journal of Pressure Vessel Technology
Article Type: Errata
J. Pressure Vessel Technol. October 2011, 133(5): 057001.
Topics: Creep, Pressure vessels, Very high temperature reactors, Nuclear power stations
Application of Negligible Creep Criteria to Candidate Materials for HTGR Pressure Vessels
J. Pressure Vessel Technol. April 2011, 133(2): 021103.
Two of the proposed high temperature gas reactors (HTGRs) under consideration for a demonstration plant have the design object of avoiding creep effects in the reactor pressure vessel during normal operation. This work addresses the criteria for negligible creep in subsection NH, Division 1 of the ASME Boiler and Pressure Vessel Code, Sec. III, other international design codes, and some currently suggested criteria modifications and their impact on permissible operating temperatures for various reactor pressure vessel materials. The goal of negligible creep could have different interpretations depending on what failure modes are considered and associated criteria for avoiding the effects of creep. It is shown that for the materials of this study, consideration of localized damage due to cycling of peak stresses results in a lower temperature for negligible creep than consideration of the temperature at which the allowable stress is governed by the creep properties. In assessing the effect of localized cyclic stresses, it is also shown that consideration of cyclic softening is an important effect that results in a higher estimated temperature for the onset of significant creep effects than would be the case if the material were cyclically hardening. There are other considerations for the selection of vessel material besides avoiding creep effects. Of interest for this review are (1) the material's allowable stress level and impact on the wall thickness (the goal being to minimize the required wall thickness) and (2) ASME code approval (inclusion as a permitted material in the relevant section and subsection of interest) to expedite regulatory review and approval. The application of negligible creep criteria to two of the candidate materials, SA533 and Mod 9Cr–1Mo (also referred to as Grade 91), and to a potential alternate, normalized and tempered 2 1 4 Cr–1Mo, is illustrated, and the relative advantages and disadvantages of the materials are discussed.
Topics: Creep, Stress, Temperature
Toward the Development of a Consensus Materials Database for Pressure Technology Applications
R. W. Swindeman, J. Ramirez, W. Ren
Proc. ASME. PVP2007, Volume 1: Codes and Standards, 499-502, July 22–26, 2007
The ASME construction code books specify materials and fabrication procedures that are acceptable for pressure technology applications. However, with few exceptions, the materials properties provided in the ASME code books provide no statistics or other information pertaining to material variability. Such information is central to the prediction and prevention of failure events. Many sources of materials data exist that provide variability information but such sources do not necessarily represent a consensus of experts with respect to the reported trends that are represented. Such a need has been identified by the ASME Standards Technology, LLC and initial steps have been taken to address these needs: however, these steps are limited to project-specific applications only, such as the joint DOE-ASME project on materials for Generation IV nuclear reactors. In contrast to light-water reactor technology, the experience base for the Generation IV nuclear reactors is somewhat lacking and heavy reliance must be placed on model development and predictive capability. The database for model development is being assembled and includes existing code alloys such as alloy 800H and 9Cr-1Mo-V steel. Ownership and use rights are potential barriers that must be addressed.
Topics: Databases, Pressure, Alloys, ASME Standards, Generation IV reactors, Model development, Construction, Failure, Light water reactors, Manufacturing
Selecting and Developing Advanced Alloys for Creep-Resistance for Microturbine Recuperator Applications
P. J. Maziasz, R. W. Swindeman
Journal: Journal of Engineering for Gas Turbines and Power
J. Eng. Gas Turbines Power. January 2003, 125(1): 310–315.
Recuperators are considered essential hardware to achieve the efficiencies desired for advanced microturbines. Compact recuperator technologies, including primary surface, plate and fin, and spiral, all require thin section materials that have high-temperature strength and corrosion resistance up to 750°C or above, and yet remain as low cost as possible. The effects of processing and microstructure on creep-rupture resistance at 750°C and 100 MPa were determined for a range of austenitic stainless alloys made into 0.1-mm foils. Two groups of alloys were identified with regard to improved creep resistance relative to type 347 stainless steel. Alloys with better creep-rupture resistance included alloys 120, 230, modified 803 and alloy 740 (formerly thermie-alloy), while alloy 214 and 625 exhibited much better creep strength. Alloys 120 and modified 803 appeared to have the most cost-effective improvements in creep strength relative to type 347 stainless steel, and should be attractive for advanced microturbine recuperator applications.
Topics: Alloys, Creep, Microturbines, Stainless steel, Rupture
Criteria for Design With Structural Materials in Combined-Cycle Applications Above 815°F
R. W. Swindeman, D. L. Marriott
J. Eng. Gas Turbines Power. April 1994, 116(2): 352–359.
Published Online: April 1, 1994
A number of materials issues related to the design of piping and support components in high-temperature fluidized bed combustor systems were examined. These issues included the availability of long-time design data on structural materials, the general character of the creep and stress rupture behavior, the performance of weldments, and the assessment of damage accumulation. Emphasis was placed on alloy 800H, but several other alloys were briefly examined for use at temperatures above 816°C (1500°F). It was concluded that the character of the creep curve ranged significantly with chemistry, processing variables, and environment, and that the specification of design allowable stresses and life estimation techniques must be approached with caution for service above 816°C (1500°F).
Topics: Combined cycles, Design, Alloys, Creep, Stress, Chemistry, Combustion chambers, Damage assessment, Fluidized beds, High temperature
Fatigue Behavior of a 22Cr-20Ni-18Co-Fe Alloy at Elevated Temperatures
T. H. Krukemyer, A. Fatemi, R. W. Swindeman
Journal: Journal of Engineering Materials and Technology
J. Eng. Mater. Technol. January 1994, 116(1): 54–61.
Published Online: January 1, 1994
An experimental investigation was conducted on Haynes Alloy 556 to study the fatigue behavior of the material at elevated temperatures. Fatigue tests were run at constant temperatures ranging from room temperature to 871°C with strain ranges from 0.265 to 1.5 percent resulting in lives between 10 2 and 10 6 cycles. Cyclic deformation properties were evaluated based on the fatigue data. Three fatigue life models were evaluated for their ability to predict the isothermal fatigue lives of the material. These included the Ostergren, Frequency Separation and Stress-Strain-Time models. Strengths and weaknesses of each model are discussed based on the experimental results.
Topics: Alloys, Fatigue, Temperature, Cycles, Deformation, Fatigue life, Fatigue testing, Separation (Technology), Stress
Developments in Ferrous Alloy Technology for High-Temperature Service
R. W. Swindeman, M. Gold
J. Pressure Vessel Technol. May 1991, 113(2): 133–140.
Developments during the past twenty-five years are outlined for the technology of ferrous alloys needed in elevated temperature service. These developments include new alloys with improved strength and corrosion resistance for use in nuclear, fossil, and petrochemical applications. Specific groups of alloys that are addressed include vanadium-modified low alloy steels, 9Cr-1Mo-V steel, niobium-modified lean stainless steels, and high chrome-nickel iron alloys. A brief description of coating and claddings for improved corrosion resistance is also provided.
Topics: Alloys, High temperature, Corrosion resistance, Alloy steel, Coating processes, Coatings, Iron alloys, Nickel, Petrochemicals, Stainless steel
Representation of the High-Temperature Tensile Behavior of Reannealed Type 304 Stainless Steel by the Voce Equation
J. Eng. Mater. Technol. April 1975, 97(2): 98–106.
Tensile tests were performed on a reference heat of type 304 stainless steel (heat 9T2796) in the laboratory reannealed condition. Testing temperatures ranged from 25 to 760 deg C (77 to 1400 deg F) and strain rates were varied from 1.5 × 10 −6 to 8.3 × 10 −2 /s. Several models were developed to represent the tensile curves, and each model was restricted to a specific range of applicability. For the inelastic strains below 0.001 a Ludwik-type formulation was developed; it was independent of strain rate but applicable for temperatures up to 760 deg C. For the strain range 0.001 to 0.05 a second Ludwik-type formulation was developed with minimal strain rate dependence, and the model was restricted to temperatures not exceeding 593 deg C (1100 deg F). For inelastic strains above 0.001 an alternative model was based on the Voce equation. The Voce model was applicable for all temperatures and strain rates and for strains to the uniform strain at the ultimate strength. The ability of the Voce model to represent tensile behavior at strain rates well below those that are practical in the laboratory experimentation was checked by comparing predicted ultimate tensile strength data against creep strength data for minimum creep rates corresponding to the tensile strain rates. The agreement was good. The ability of the Voce model to predict uniform strain behavior was also examined. In the creep range the Voce model overestimated uniform strains for temperatures below 649 deg C (1200 deg F) and underestimated them for temperatures above 649 deg C (1200 deg F).
Topics: High temperature, Stainless steel, Temperature, Creep, Heat, Tensile strength, Testing
Closure to "Discussions of 'The Failure of Structural Metals Subjected to Strain-Cycling Conditions'" (1959, ASME J. Basic Eng., 81, pp. 208–210)
R. W. Swindeman, D. A. Douglas
Journal: Journal of Fluids Engineering
Article Type: Closures
J. Fluids Eng. June 1959, 81(2): 211–212.
Published Online: June 1, 1959
Topics: Failure, Structural metals
The Failure of Structural Metals Subjected to Strain-Cycling Conditions
Data showing the isothermal strain-cycling capacity of three metals, Inconel, Hastelloy B, and beryllium are presented. It is noted that at frequencies of 0.5 cycle per min the data satisfied an equation of the form N α ϵ p = K, where N is the number of cycles to failure, ϵ p is the plastic strain per cycle, and α and K are constants whose values depend on the material and test conditions. Data on Inconel are given to establish the effect of grain size, specimen geometry, temperature, and frequency. It is found that, at temperatures above 1300 F, grain size and frequency exert a pronounced effect on the rupture life. Fine-grained metal survives more cycles before failure than coarse-grained material. Long time cycles shorten the number of cycles to failure when the strain per cycle is low. Thermal-strain-cycling data for Inconel are compared to strain-cycling data at the same mean temperature. Good correlation is found to exist between the two types of tests.
Topics: Failure, Structural metals, Cycles, Temperature, Grain size, Metals, Geometry, Rupture