scholarly journals Stress Rupture Testing and Analysis of the NASA WSTF: JPL Carbon Overwrapped Pressure Vessels

2007 ◽  
Author(s):  
Nathanael Greene
Keyword(s):  
Stress Rupture ◽  
Pressure Vessels ◽  
Stress Rupture Testing

scholarly journals Influence of the Heat Input on the Dendritic Solidification Structure and the Mechanical Properties of 2.25Cr-1Mo-0.25V Submerged-Arc Weld Metal

2021 ◽  
Author(s):  
Hannah Schönmaier ◽  
Ronny Krein ◽  
Martin Schmitz-Niederau ◽  
Ronald Schnitzer
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Heat Input ◽  
Stress Rupture ◽  
Pressure Vessels ◽  
Rupture Time ◽  
Solidification Structure ◽  
Welding Parameters ◽  
Austenite Grain Size ◽  
Submerged Arc

AbstractThe alloy 2.25Cr-1Mo-0.25V is commonly used for heavy wall pressure vessels in the petrochemical industry, such as hydrogen reactors. As these reactors are operated at elevated temperatures and high pressures, the 2.25Cr-1Mo-0.25V welding consumables require a beneficial combination of strength and toughness as well as enhanced creep properties. The mechanical properties are known to be influenced by several welding parameters. This study deals with the influence of the heat input during submerged-arc welding (SAW) on the solidification structure and mechanical properties of 2.25Cr-1Mo-0.25V multilayer metal. The heat input was found to increase the primary and secondary dendrite spacing as well as the bainitic and prior austenite grain size of the weld metal. Furthermore, it was determined that a higher heat input during SAW causes an increase in the stress rupture time and a decrease in Charpy impact energy. This is assumed to be linked to a lower number of weld layers, and therefore, a decreased amount of fine grained reheated zone if the multilayer weld metal is fabricated with higher heat input. In contrast to the stress rupture time and the toughness, the weld metal’s strength, ductility and macro-hardness remain nearly unaffected by changes of the heat input.

An Analysis of Filament Overwound Toroidal Pressure Vessels and Optimum Design of Such Structures

2002 ◽  
Vol 124 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Shuguang Li ◽  
John Cook
Keyword(s):  
Optimum Design ◽  
Equivalent Stress ◽  
Mechanical Damage ◽  
Stress Rupture ◽  
Optimization Procedure ◽  
Pressure Vessels ◽  
Thickness Variation ◽  
Von Mises Equivalent Stress ◽  
Metal Liner ◽  
Von Mises

This paper is concerned with the membrane shell analysis of filament overwound toroidal pressure vessels and optimum design of such pressure vessels using the results of the analysis by means of mathematical nonlinear programming. The nature of the coupling between overwind and linear has been considered based on two extreme idealizations. In the first, the overwind is rigidly coupled with the liner, so that the two deform together in the meridional direction as the vessel dilates. In the second, the overwind is free to slide relative to the linear, but the overall elongations of the two around a meridian are identical. Optimized designs with the two idealizations show only minor differences, and it is concluded that either approximation is satisfactory for the purposes of vessel design. Aspects taken into account are the intrinsic overwind thickness variation arising from the winding process and the effects of fiber pre-tension. Pre-tension can be used not only to defer the onset of yielding, but also to achieve a favorable in-plane stress ratio which minimizes the von Mises equivalent stress in the metal liner. Aramid fibers are the most appropriate fibers to be used for the overwind in this type of application. The quantity of fiber required is determined by both its short-term strength and its long-term stress rupture characteristics. An optimization procedure for the design of such vessels, taking all these factors into account, has been established. The stress distributions in the vessels designed in this way have been examined and discussed through the examples. A design which gives due consideration of possible mechanical damage to the surface of the overwind has also been addressed.

High-Temperature Failures

2012 ◽  
pp. 415-459
Keyword(s):  
High Temperature ◽  
Stress Rupture ◽  
Creep Life Prediction ◽  
Creep Curves ◽  
Creep Fatigue ◽  
Temperature Fracture ◽  
Underlying Mechanisms ◽  
Thermomechanical Damage ◽  
Stress Rupture Testing ◽  
Related Design

Abstract This chapter compares and contrasts the high-temperature behaviors of metals and composites. It describes the use of creep curves and stress-rupture testing along with the underlying mechanisms in creep deformation and elevated-temperature fracture. It also discusses creep-life prediction and related design methods and some of the factors involved in high-temperature fatigue, including creep-fatigue interaction and thermomechanical damage.

dc Potential Drop Technique in Creep Stress Rupture Testing

JOM ◽  
1985 ◽  
Vol 37 (10) ◽  
pp. 44-49 ◽  
Author(s):  
Ioannis P. Vasatis ◽  
Regis M. Pelloux
Keyword(s):  
Stress Rupture ◽  
Potential Drop ◽  
Creep Stress ◽  
Dc Potential ◽  
Stress Rupture Testing ◽  
Drop Technique

Stress-Rupture Behavior of Alloys 230 and 617 for High Temperature Applications

2010 ◽  
Author(s):  
Muhammad H. Hasan ◽  
S. Chatterjee ◽  
A. K. Roy ◽  
Joydeep Pal
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Hydrogen Generation ◽  
Tensile Deformation ◽  
Stress Rupture ◽  
Simultaneous Increase ◽  
Creep Stress ◽  
Very High Temperature Reactor ◽  
Stress Rupture Testing ◽  
Rupture Behavior

Austenitic Alloys 230 and 617 have been identified to be the two most suitable structural materials for heat exchanger application within the purview of the next generation nuclear plant (NGNP) program. The NGNP program is aimed at developing electricity and hydrogen using heat from very-high-temperature-reactor (VHTR). A maximum operating temperature of 950 °C has been recommended to achieve the highest possible efficiency in both electricity and hydrogen generation. The identification of Alloys 617 and 230 as heat exchanger materials was based on their excellent resistance to high-temperature degradations including creep, stress-rupture, fatigue and tensile deformation. Extensive efforts have been made to evaluate the creep and stress-rupture behavior of both alloys at temperatures relevant to the NGNP application. This paper presents the results of stress-rupture testing involving these alloys as functions of applied stress and temperature. The time to rupture was gradually reduced with simultaneous increase in stress and temperature, leading to a gradual reduction in the Larson-Miller-Parameter (LMP) indicating enhanced rupture tendency.

Multiaxial Stress Rupture Testing and Compendium of Data for Creep Resisting Steels

1982 ◽  
Vol 104 (4) ◽  
pp. 291-296 ◽  
Author(s):  
R. J. Browne ◽  
D. Lonsdale ◽  
P. E. J. Flewitt
Keyword(s):  
Stress Rupture ◽  
Creep Rupture ◽  
Estimation Methods ◽  
Multiaxial Stress ◽  
Life Estimation ◽  
Uniaxial Creep ◽  
Rupture Data ◽  
Stress Rupture Testing ◽  
Present Life ◽  
Rupture Criterion

Recently, there has been an increasing need for more accurate methods of predicting the life of components operating in the creep range. Although many such components are invariably subject to multiaxial stress systems, present life estimation methods utilize available uniaxial creep rupture data via a representative stress for the component. This stress is usually empirically derived and in many cases leads to undue conservatism in life estimates because no account is taken of the creep and rupture response of the material to multiaxial stresses. This paper reviews the various multiaxial stress rupture test techniques which have been employed to determine the multiaxial stress rupture criterion. The multiaxial stress rupture data available in the literature for some commonly used creep resisting steels are compiled and discussed.

Sign in / Sign up

Export Citation Format

Share Document