Constitutive flow behavior of IFAC-1 austenitic stainless steel depicting strain saturation over a wide range of strain rates and temperatures

2014 ◽  
Vol 56 ◽  
pp. 565-571 ◽  
Author(s):  
Dipti Samantaray ◽  
Alpesh Patel ◽  
Utpal Borah ◽  
S.K. Albert ◽  
A.K. Bhaduri
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Flow Behavior ◽  
Strain Rates ◽  
Wide Range

Serrated Flow in 316LN Austenitic Stainless Steel

2013 ◽  
Vol 455 ◽  
pp. 159-162 ◽  
Author(s):  
Zhi Qiang Xu ◽  
Yin Zhong Shen
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Rate ◽  
Room Temperature ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Dynamic Strain ◽  
Strain Rates ◽  
Serrated Flow ◽  
Substitutional Solute

Serrated flow behavior of the 316LN austenitic stainless steel was investigated through tensile tests at initial strain rates of 2×10-5 to 10-4 s-1 at temperatures ranging from room temperature to 1048 K. Serrated flow occurred at room temperature and 6981048K at the strain rate of 2×10-4 s-1, as well as at temperatures of 623673 K at the strain rate of 2×10-5 s-1. Type A, A+B, C and E serrations appeared. The activation energy for the occurrence of serrated flow at high temperatures was about 327 kJ/mol. The dynamic strain aging caused by the interaction between substitutional solute Cr atoms and moving dislocations is considered as the mechanism of serrated flow at the temperatures higher than 973 K.

Rheo-Optics Studies in the Development of Hybrid Liquid Crystalline Based Mwir Polarizers

1999 ◽  
Vol 559 ◽  
Author(s):  
P.T. Mather ◽  
W. Barnes ◽  
P.J. Hood ◽  
T.J. Bunning
Keyword(s):  
Liquid Crystalline ◽  
Flow Behavior ◽  
Optical Microscope ◽  
Processing Technique ◽  
Strain Rates ◽  
Alignment Layer ◽  
Small Pitch ◽  
Wide Range ◽  
Measured Polarization ◽  
Free Films

ABSTRACTWe present here a rheo-optical study of the flow behavior of two cholesteric liquid crystals, one with a large pitch and one with a small pitch. The large pitch compound has been investigated as a possible fixed wavelength polarizer in the mid-wavelength infra-red region (3-5 micron). The investigation of these compounds is driven by their low melt viscosity and ability to vitrify order, and thus functionality, into films with a wide range of thickness. In our attempts to obtain consistent thin films with reproducible contrast ratios, we explored the defect textures of both compounds under a polarizing optical microscope. These materials were sheared at various strain rates and at various temperatures in an attempt to determine the best processing window for defect free films. The pitch lengths of the two materials investigated were 160 and 1330 nm. The flow behavior of the large pitch material resembles a pure nematic with defect refinement taking place under flow. The short pitch material exhibited the typical Grandjean oily streaks upon shearing followed by coarsening. Observations made during this rheological study were used to identify a processing technique for the large pitch materials. Upon application of a conventional buffed alignment layer, films with consistent quality were routinely made. The measured polarization contrast of >70:1 exceeds the values obtained from state-of-the art commercial polarizers in this wavelength regime.

A Mathematical Description for the Stress-Strain Behavior of Annealed 2 1/4 Cr-1 Mo Steel

1976 ◽  
Vol 98 (2) ◽  
pp. 118-125 ◽  
Author(s):  
R. L. Klueh ◽  
T. L. Hebble
Keyword(s):  
Mathematical Description ◽  
Flow Behavior ◽  
True Strain ◽  
Empirical Relationship ◽  
Tensile Tests ◽  
Strain Rates ◽  
Strain Behavior ◽  
Test Conditions ◽  
Wide Range ◽  
Strain Data

We have conducted a detailed series of tensile tests on one heat of annealed 2 1/4 Cr-1 Mo steel over the range 25 to 593°C (75 to 1100°F) and at nominal strain rates of 0.4, 0.04, 0.004, and 0.0004/min. To determine an empirical relationship to represent the flow behavior, we fitted the true-stress true-strain data from these tests to several proposed models. The models fit were those proposed by Hollomon, Ludwik, Ludwigson, and Voce. From a comparison of the standard error of estimate, the Voce equation was concluded to be the best mathematical description of the data under most test conditions and the best single representation over the wide range of test conditions.

Hydrogen Embrittlement Of Austenitic Stainless Steel

CORROSION ◽  
1965 ◽  
Vol 21 (2) ◽  
pp. 53-56 ◽  
Author(s):  
M. B. WHITEMAN ◽  
A. R. TROIANO
Keyword(s):  
Activation Energy ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Low Temperatures ◽  
High Strain ◽  
Complete Recovery ◽  
Strain Rates ◽  
Body Centered Cubic ◽  
Thin Sections ◽  
310 Stainless Steel

Abstract Type 310 stainless steel in thin sections was embrittled by hydrogen. The temperature and strain rate dependence of this embrittlement was almost analogous to that well-established for hydrogenated body-centered cubic (b.c.c.) metals, differing only in that at low temperatures and relatively high strain rates complete recovery in ductility was not achieved. The activation energy for recovery in ductility, determined by aging at several temperatures, was 10,900 cal/mole.

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