Temperature-stress dependence of the rupture life of polystyrene under hydrostatic pressure

1979 ◽  
Vol 14 (5) ◽  
pp. 632-636
Author(s):  
A. I. Petrov ◽  
V. I. Betekhtin ◽  
V. A. Zakrevskii
Keyword(s):  
Hydrostatic Pressure ◽  
Temperature Stress ◽  
Rupture Life ◽  
Stress Dependence

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.

Creep and Fracture Behavior of Centrifugal Cast HP40Nb Alloy Containing Lead

2012 ◽  
Author(s):  
Tao Chen ◽  
Xuedong Chen ◽  
Yunrong Lu ◽  
Juan Ye ◽  
Xiaoming Lian
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Centrifugal Casting ◽  
Rupture Life ◽  
Stress Rupture ◽  
Creep Damage ◽  
Threshold Value ◽  
High Temperature Stress ◽  
Furnace Tube ◽  
Technical Specifications

Centrifugal cast HP40Nb alloys are commonly used as ethylene pyrolysis and reformer furnace tube materials. The actual wall temperature can usually reach 1423 K. The technical specifications require that the rupture life shall be at least 120 h under test condition of 1373 K at 17 MPa. The effects of amounts of Lead on the creep and stress rupture performance of the centrifugal cast HP40Nb alloy have been investigated at the temperature of 1373 K and the constant stress of 17 MPa. In this paper, HP40Nb alloy tubes with different contents of Lead element by centrifugal casting were selected, by high temperature stress rupture test and microscopic observation of creep damage, relationship between the content of Lead and high temperature stress rupture lives was given, as well as the threshold value of Lead element. It could provide the basis for ethylene pyrolysis furnace tubes manufacturers and design specifications.

scholarly journals Collective Evaluation of Temperature and Stress Dependence of Creep Rupture Life in Austenitic Stainless Steels

1995 ◽  
Vol 81 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Hideo NAKAKUKI ◽  
Kouichi MARUYAMA ◽  
Hiroshi OIKAWA ◽  
Koichi YAGI
Keyword(s):  
Stainless Steels ◽  
Rupture Life ◽  
Austenitic Stainless Steels ◽  
Creep Rupture ◽  
Stress Dependence

?Pole shift? effect in a study of the temperature-stress dependence of life

1974 ◽  
Vol 6 (2) ◽  
pp. 127-133 ◽  
Author(s):  
V. R. Regel' ◽  
T. P. Sanfirova ◽  
A. I. Slutsker
Keyword(s):  
Temperature Stress ◽  
Stress Dependence ◽  
Shift Effect

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 176-177
Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Volume ◽  
Precipitate Morphology ◽  
Stress Rupture Life ◽  
Nickel Base ◽  
Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

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