Parameter Representation of Low-Temperature Yield Behavior of Body-Centered Cubic Transition Metals

1966 ◽  
Vol 88 (2) ◽  
pp. 518-524 ◽  
Author(s):  
P. E. Bennett ◽  
G. M. Sinclair

In the low-temperature range, the engineering yield strength of polycrystalline bcc metals can change by a factor of 10 or more with serious consequences appearing in the form of catastrophic brittle fracture. Engineering variables known to have an important effect on the yield behavior are state of stress, temperature, loading or strain rate, composition, and microstructure. For iron, chromium, molybdenum, and tungsten, it is shown that yield behavior can be represented by a single-valued relation between two dimensionless parameters.

2001 ◽  
Vol 677 ◽  
Author(s):  
Meijie Tang ◽  
Ladislas P. Kubin

ABSTRACTIn order to study the dislocation density evolution of body centered cubic (bcc) crystals at low temperature by dislocation dynamics (DD) simulations, we investigated carefully three different boundary conditions (BC) for DD, i.e., the quasi-free surface BC, the flux-balanced BC, and the periodic BC. The latter two BCs can account for the dislocation loss from the boundary of the finite simulation box. PBC can also eliminate the influence of surfaces and improve the line connectivity. We have found that the PBC provides a convenient and effective boundary condition for DD simulations and have applied it to the study of dislocation density evolution of bcc metals during stage 0 deformation at low temperature.


1986 ◽  
Vol 81 ◽  
Author(s):  
H. T. Lin ◽  
R. C. Wilcox ◽  
B. A. Chin

AbstractThe sensitivity of iron-based LRO alloys to strain rate at elevated temperatures was investigated. The tensile results indicate that the iron-based LRO alloys exhibit a positive temperature dependence of yield behavior, but are insensitive to variations in strain rate between 10-5 and 100 sec-1. These observations, along with SEM and TEM results, suggest that previous proposed diffusion-controlled mechanisms are not responsible for the increase in yield strength with increasing temperature.


2021 ◽  
Vol 9 (6) ◽  
pp. 604
Author(s):  
Du-Song Kim ◽  
Hee-Keun Lee ◽  
Woo-Jae Seong ◽  
Kwang-Hyeon Lee ◽  
Hee-Seon Bang

The International Maritime Organization has recently updated the ship emission standards to reduce atmospheric contamination. One technique for reducing emissions involves using liquefied natural gas (LNG). The tanks used for the transport and storage of LNG must have very low thermal expansion and high cryogenic toughness. For excellent cryogenic properties, high-Mn steel with a complete austenitic structure is used to design these tanks. We aim to determine the optimum welding conditions for performing Laser-MIG (Metal Inert Gas) hybrid welding through the MIG leading and laser following processes. A welding speed of 100 cm/min was used for welding a 15 mm thick high-Mn steel plate. The welding performance was evaluated through mechanical property tests (tensile and yield strength, low-temperature impact, hardness) of the welded joints after performing the experiment. As a result, it was confirmed that the tensile strength was slightly less than 818.4 MPa, and the yield strength was 30% higher than base material. The low-temperature impact values were equal to or greater than 58 J at all locations in the weld zone. The hardness test confirmed that the hardness did not exceed 292 HV. The results of this study indicate that it is possible to use laser-MIG hybrid welding on thick high-Mn steel plates.


RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23719-23724
Author(s):  
Md. Lokman Ali

The effect of transition-metals (TM) addition on the mechanical properties of CrCoNi medium entropy alloys (MEAs) was investigated.


RSC Advances ◽  
2017 ◽  
Vol 7 (21) ◽  
pp. 12524-12533 ◽  
Author(s):  
Lei Liu ◽  
Shi-Da Xu ◽  
Feng-Yun Wang ◽  
Yue-Jun Song ◽  
Jie Liu ◽  
...  

Nitrogen doped ordered mesoporous carbons with a 3-D body-centered cubic pore structure have been synthesized by means of a low-temperature autoclaving route under basic conditions, showing excellent performances for supercapacitors and CO2 capture.


2016 ◽  
Vol 838-839 ◽  
pp. 171-176 ◽  
Author(s):  
P. Sartkulvanich ◽  
Don Li ◽  
Ernest Crist ◽  
K.O. Yu

The SPF experiments were conducted on two sheet materials: Ti-6Al-4V Fine Grain Sheet (Ti-64 FGS) and Ti-6Al-4V Standard (Ti-64 STD) to investigate the influence of SPF conditions on the reduction of yield strength (YS) and change in microstructure for those two products. Results show that a) Ti-64 FGS has better formability at high testing strain rate than Ti-64 STD, b) initial YS values of Ti-64 FGS is 10% higher than Ti-64 STD, c) reduction of YS in Ti-64 FGS is 15-27%, which is much higher than 4-9% YS reduction for Ti-64 STD, d) the most influential factor on YS reduction is the forming temperature for Ti-64 FGS, but is the strain rate for Ti-64 STD, and e) microstructure pictures of initial Ti-64 FGS before forming is finer and more isotropic than Ti-64 STD, but Ti64 FGS shows more grain growth after SPF, which results in greater drop of yield strength.


2000 ◽  
Vol 646 ◽  
Author(s):  
Haruyuki Inui ◽  
Koji Ishikawa ◽  
Masaharu Yamaguchi

ABSTRACTEffects of ternary additions on the deformation behavior of single crystals of MoSi2 with the hard [001] and soft [0 15 1] orientations have been investigated in compression and compression creep. The alloying elements studied include V, Cr, Nb and Al that form a C40 disilicide with Si and W and Re that form a C11b disilicide with Si. The addition of Al is found to decrease the yield strength of MoSi2 at all temperatures while the additions of V, Cr and Nb are found to decrease the yield strength at low temperatures and to increase the yield strength at high temperatures. In contrast, the additions of W and Re are found to increase the yield strength at all temperatures. The creep strain rate for the [001] orientation is significantly lower than that for the [0 15 1] orientation. The creep strain rate for both orientations is significantly improved by alloying with ternary elements such as Re and Nb.


1994 ◽  
Vol 26 (7) ◽  
pp. 477-491
Author(s):  
B. Z. Margolin ◽  
V. A. Shvetsova ◽  
M. A. Sergeeva
Keyword(s):  

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