Fatigue Design Criteria for Pressure Vessel Alloys

1977 ◽  
Vol 99 (4) ◽  
pp. 584-592 ◽  
Author(s):  
C. E. Jaske ◽  
W. J. O’Donnell
Keyword(s):  
Pressure Vessel ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Austenitic Steels ◽  
Design Criteria ◽  
Fatigue Design ◽  
Alloy 800 ◽  
Pressure Vessel Steels ◽  
Fatigue Data ◽  
Mean Stresses

Fatigue design criteria for pressure vessel steels are developed herein based on analysis of available material data between room temperature and 427 C (800 F). Strain-controlled low-cycle and high-cycle fatigue data for austenitic steels, alloy 800, alloy 600, and alloy 718 were evaluated. The effects of mean stresses were considered and design curves were proposed for use in Sections III and VIII of the ASME Boiler and Pressure Vessel Code.

Development of Fatigue Design Curves for Pressure Vessel Alloys Using a Modified Langer Equation

1979 ◽  
Vol 101 (4) ◽  
pp. 292-297 ◽  
Author(s):  
D. R. Diercks
Keyword(s):  
Pressure Vessel ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Austenitic Stainless Steels ◽  
Cyclic Stress ◽  
Allowable Stress ◽  
Fitting Procedure ◽  
Fatigue Design ◽  
Alloy 800 ◽  
Best Fit

The Jaske and O’Donnell [1] curve-fitting procedure for analyzing fatigue data generated between room temperature and 427° C (800° F) for several pressure vessel alloys is reexamined in the present paper. Substantial improvements over their best-fit curves to the data are found to result from two proposed modifications to their procedure, namely 1) the use of a variable exponent in the Langer equation, and 2) minimization of the sum of the squares of the errors in the logarithms of the cyclic-stress amplitudes rather than in the stress amplitudes directly. Likewise, important differences are observed for the resultant allowable stress-amplitude values for design purposes. In particular, the present analysis permits higher allowable stress amplitudes in the critical low-cycle fatigue-life region for the austenitic stainless steels, alloy 800, and alloy 600. Two best-fit curves and the associated sets of allowable stress amplitudes, corresponding to the inclusion or deletion of load-controlled data, are obtained for alloy 718.

scholarly journals Fatigue Design Curves for 6061-T6 Aluminum

1997 ◽  
Vol 119 (2) ◽  
pp. 211-215 ◽  
Author(s):  
G. T. Yahr
Keyword(s):  
Base Metal ◽  
Neutron Source ◽  
Pressure Vessel ◽  
Research Reactor ◽  
Mean Stress ◽  
Design Curve ◽  
Stress Effects ◽  
Fatigue Design ◽  
Fatigue Data ◽  
Class 1

A request has been made to the ASME Boiler and Pressure Vessel Committee that 6061-T6 aluminum be approved for use in the construction of Class 1 welded nuclear vessels so it can be used for the pressure vessel of the Advanced Neutron Source research reactor. Fatigue design curves with and without mean stress effects have been proposed. A knock-down factor of 2 is applied to the design curve for evaluation of welds. The basis of the curves is explained. The fatigue design curves are compared to fatigue data from base metal and weldments.

High-Cycle Fatigue Design Evolution and Experience of Free-Standing Combustion Turbine Blades

1992 ◽  
Vol 114 (2) ◽  
pp. 284-292 ◽  
Author(s):  
A. J. Scalzo
Keyword(s):  
Turbine Blade ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Design Criteria ◽  
Cycle Fatigue ◽  
Free Standing ◽  
Fatigue Design ◽  
Turbine Blade Design ◽  
Westinghouse Electric ◽  
Cooling Air

Combustion turbine blade design criteria can generally be classified as either temperature or fatigue related. Since less is usually known about the factors influencing the fatigue phenomenon, it is considered the more challenging. In addition, as analytical and experimental techniques became more sophisticated and more accurate, the natural tendency was to replace archaic “guidelines” or “rules” with less conservative approaches that at times led to the discovery of new high-cycle fatigue “thresholds.” This paper presents the evolution of the combustion turbine blade high cycle fatigue design criteria for free-standing blades. It also presents the analysis and corrective actions taken to resolve several unique combustion turbine blade fatigue problems, all encountered over a 35-year period while the author has been employed at Westinghouse Electric Corporation. Included are high-cycle fatigue problems due to cooling air leakage, seal pin friction, and combustion temperature maldistribution, as well as flow-induced nonsynchronous vibration.

scholarly journals High-Cycle Fatigue Design Evolution and Experience of Freestanding Combustion Turbine Blades

1991 ◽  
Author(s):  
A. J. Scalzo
Keyword(s):  
Turbine Blade ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Design Criteria ◽  
Cycle Fatigue ◽  
Design Evolution ◽  
Fatigue Design ◽  
Turbine Blade Design ◽  
Westinghouse Electric ◽  
Cooling Air

Combustion turbine blade design criteria can generally be classified as either temperature or fatigue related. Since less is usually known about the factors influencing the fatigue phenomenon, it is considered the more challenging. In addition, as analytical and experimental techniques became more sophisticated and more accurate, the natural tendency was to replace archaic “guidelines” or “rules” with less conservative approaches that at times led to the discovery of new high cycle fatigue “thresholds”. This paper presents the evolution of the combustion turbine blade high cycle fatigue design criteria for freestanding blades; and, also presents the analysis and corrective actions taken to resolve several unique combustion turbine blade fatigue problems, all encountered over a thirty-five year period while the author has been employed at Westinghouse Electric Corporation. Included are high-cycle fatigue problems due to cooling air leakage, seal pin friction, combustion temperature maldistribution, as well as flow-induced nonsynchronous vibration.

Evaluation of a Ni-20Cr Alloy Processed by Multi-Axis Forging

2006 ◽  
Vol 503-504 ◽  
pp. 793-798 ◽  
Author(s):  
R. DiDomizio ◽  
M.F.X. Gigliotti ◽  
J.S. Marte ◽  
P.R. Subramanian ◽  
Vener Valitov
Keyword(s):  
Grain Size ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Thermal Exposure ◽  
Fatigue Properties ◽  
Processing Route ◽  
Bulk Alloy ◽  
Processed Material ◽  
Fatigue Data ◽  
Novel Processing

This paper discusses the development of a novel processing route to produce ultra finegrain bulk alloy forgings; the microstructural response of these forgings to thermal exposure; and the comparison of mechanical properties to those from conventionally processed material. A Ni- 20Cr [wt%] alloy was processed by near-isothermal multi-axis forging to a grain size of approximately 1 μm. A heat-treatment study over the range 900 to 1200°C was conducted to determine the resultant grain size as a function of time and temperature. Tensile properties were measured at room temperature, 500°C, and 930°C. High-cycle fatigue properties were measured at room temperature. The room-temperature tensile strength was approximately 2.5 times greater than that of conventionally processed Ni-20Cr. Fatigue data showed that the room-temperature highcycle fatigue run-out stress was greater than 100% of the yield stress.

Temperature Dependence of Reactor Water Environmental Fatigue Effects on Carbon, Low Alloy and Austenitic Stainless Steels

2008 ◽  
Author(s):  
William James O’Donnell ◽  
William John O’Donnell
Keyword(s):  
Environmental Effects ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Design Criteria ◽  
Strain Rates ◽  
Worst Case ◽  
Reactor Water ◽  
Fatigue Design ◽  
Fatigue Data ◽  
Water Effects

Recent studies of the environmental fatigue data for carbon, low alloy and austenitic stainless steels have shown that reactor water effects are significantly less deleterious as temperatures are reduced below 350 °C (662 °F). At temperatures below 150 °C (302 °F) the reduction in life due to reactor water environmental effects is less than a factor of 2, and the existing ASME Code Section III fatigue design curves for air can be used. The latter include a factor of 20 on cycles whereas the ASME Subgroup on Fatigue Strength (SGFS) has determined that a factor of 10 should be used on the mean failure curves which include reactor water effects. These factors account for scatter in the data, surface finish effects, size effects, and environmental effects. Reactor water environmental degradation dependence on temperature is determined using variations of the statistical models developed by Chopra and Shack, Higuchi, Iiada, Asada, Nakamura, Van Der Sluys, Yukawa, Mehta, Leax and Gosselin, References [1 through 22]. Comparisons of the resulting proposed environmental fatigue design criteria with reactor water environmental fatigue data are made. These comparisons show that the Code factors of 2 and 20 on stress and cycles are maintained for air environments, and the 2 and 10 Code factors are maintained for the reactor water environments. Environmental fatigue criteria are given for both worst case strain rates and for arbitrary strain rates. These design criteria do not require the designer to consider sequence of loading, hold times, transient rates, and other operating details which may change during 60 years of plant operation.

Fatigue Design in Mining Size Reduction Equipment

1982 ◽  
Vol 104 (2) ◽  
pp. 112-119
Author(s):  
V. Svalbonas
Keyword(s):  
Cast Iron ◽  
High Technology ◽  
Size Reduction ◽  
Design Criteria ◽  
Nondestructive Examination ◽  
Fatigue Design ◽  
Fatigue Data ◽  
Structural Failures ◽  
Technology Industries ◽  
High Technology Industries

The mining size reduction equipment industry is reviewed regarding efforts to obtain a consistent fatigue design philosophy. Serious structural failures, which have prompted various company efforts in this area, are reviewed. Efforts to obtain design criteria have been hampered by lack of data concerning the mundane materials, such as cast iron, used in the fabrications. Similar research from high technology industries, therefore, does not provide directly applicable data. However, new testing efforts are underway, and basic fatigue data is being gathered with the goal of providing consistent design, fabrication and nondestructive examination programs.

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