Role of Nitrogen Content on Interrelationship Between Creep Deformation and Damage Behaviour of 316LN SS

2022 ◽  
Author(s):  
V. Ganesan ◽  
C. Praveen ◽  
J. Christopher ◽  
G. V. Prasad Reddy ◽  
M. Vasudevan
Keyword(s):  
Nitrogen Content ◽  
Creep Deformation ◽  
316Ln Ss

scholarly journals Role of carbon and nitrogen in the improvement of corrosion resistance of new powder metallurgy Co-Cr-Mo alloys

2020 ◽  
Vol 38 (3) ◽  
pp. 273-286 ◽  
Author(s):  
Cristina Garcia-Cabezon ◽  
Celia Garcia-Hernandez ◽  
Maria L. Rodriguez-Mendez ◽  
Gemma Herranz ◽  
Fernando Martin-Pedrosa
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Nitrogen Content ◽  
Powder Metallurgy Technique ◽  
Carbon And Nitrogen ◽  
Physiological Conditions ◽  
Carbon And Nitrogen Content ◽  
Astm F75

AbstractMicrostructural changes that result in relevant improvements in mechanical properties and electrochemical behavior can be induced using different sintering conditions of ASTM F75 cobalt alloys during their processing using powder metallurgy technique. It has been observed that the increase in carbon and nitrogen content improves corrosion resistance and mechanical properties as long as the precipitation of carbides and nitrides is avoided, thanks to the use of rapid cooling in water after the sintering stage. In addition, the reduction of the particle size of the powder improves hardness and resistance to corrosion in both acid medium with chlorides and phosphate-buffered medium that simulates the physiological conditions for its use as a biomaterial. These results lead to increased knowledge of the role of carbon and nitrogen content in the behavior displayed by the different alloys studied.

scholarly journals Effects of Fire and Large Herbivores on Canopy Nitrogen in a Tallgrass Prairie

2019 ◽  
Vol 11 (11) ◽  
pp. 1364 ◽  
Author(s):  
Bohua Ling ◽  
Edward J. Raynor ◽  
Douglas G. Goodin ◽  
Anthony Joern
Keyword(s):  
Spatial Variability ◽  
Nitrogen Content ◽  
Tallgrass Prairie ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Grazing History ◽  
One Year ◽  
Canopy Nitrogen

This study analyzed the spatial heterogeneity of grassland canopy nitrogen in a tallgrass prairie with different treatments of fire and ungulate grazing (long-term bison grazing vs. recent cattle grazing). Variogram analysis was applied to continuous remotely sensed canopy nitrogen images to examine the spatial variability in grassland canopies. Heterogeneity metrics (e.g., the interspersion/juxtaposition index) were calculated from the categorical canopy nitrogen maps and compared among fire and grazing treatments. Results showed that watersheds burned within one year had higher canopy nitrogen content and lower interspersions of high-nitrogen content patches than watersheds with longer fire intervals, suggesting an immediate and transient fire effect on grassland vegetation. In watersheds burned within one year, high-intensity grazing reduced vegetation density, but promoted grassland heterogeneity, as indicated by lower canopy nitrogen concentrations and greater interspersions of high-nitrogen content patches at the grazed sites than at the ungrazed sites. Variogram analyses across watersheds with different grazing histories showed that long-term bison grazing created greater spatial variability of canopy nitrogen than recent grazing by cattle. This comparison between bison and cattle is novel, as few field experiments have evaluated the role of grazing history in driving grassland heterogeneity. Our analyses extend previous research of effects from pyric herbivory on grassland heterogeneity by highlighting the role of grazing history in modulating the spatial and temporal distribution of aboveground nitrogen content in tallgrass prairie vegetation using a remote sensing approach. The comparison of canopy nitrogen properties and the variogram analysis of canopy nitrogen distribution provided by our study are useful for further mapping grassland canopy features and modeling grassland dynamics involving interplays among fire, large grazers, and vegetation communities.

The role of the leaves in the accumulation of nitrogen by wheat during ear development

1963 ◽  
Vol 14 (6) ◽  
pp. 725 ◽  
Author(s):  
TF Neales ◽  
MJ Anderson ◽  
IF Wardlaw
Keyword(s):  
Nitrogen Content ◽  
External Factor ◽  
Amino Nitrogen ◽  
Wheat Plant ◽  
Dry Weight ◽  
Leaf Removal ◽  
Ear Development ◽  
Rooting Medium ◽  
Grain Nitrogen

When wheat plants were deprived of nitrogen in the rooting medium at anthesis there was a small, but significant, increase in the nitrogen content of the grain at maturity. It was shown that there was a greater migration of nitrogen from the leaves and stem to the ear in plants deprived of nitrogen than in those plants supplied with nitrogen throughout ear development. In an examination of the effects on grain nitrogen content of leaf removal at anthesis, it was shown that this treatment reduces the uptake of nitrogen into the culm and the nitrogen content of the grain at maturity. Ear shading treatments significantly reduced the total nitrogen content of the grain in one experiment. Ear shading also decreased the amino nitrogen, and increased the nitrate nitrogen, content of the ear. Variation of the grain dry weight per ear, induced by shading, by defoliation treatments, or by differences in variety, were positively correlated with grain nitrogen content. Either the movement of dry matter and nitrogen into the ear are interdependent, or they are both promoted by some external factor, such as rate of growth of the ear. The possible importance of the leaves of the wheat plant in promoting the uptake of nitrogen into the culm and in supplying nitrogen to the grain is discussed.

Nitrogen Enhanced 316LN Austenitic Stainless Steel for Sodium Cooled Fast Reactors

2013 ◽  
Vol 794 ◽  
pp. 670-680 ◽  
Author(s):  
Tammana Jayakumar ◽  
A.K. Bhaduri ◽  
M.D. Mathew ◽  
Shaju K. Albert ◽  
U. Kamachi Mudali
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Weld Metal ◽  
Nitrogen Content ◽  
Low Cycle Fatigue ◽  
Hot Cracking ◽  
Cycle Fatigue ◽  
Fast Reactors ◽  
Delta Ferrite ◽  
316Ln Ss

For the future sodium-cooled fast reactors (SFRs), which are envisaged with a design life of 60 years, nitrogen-enhanced 316LN austenitic stainless steel (SS) with improved high-temperature properties is being developed. To optimize the enhanced nitrogen content in 316LN SS, the effect of nitrogen on its tensile, creep and low cycle fatigue behavior has been investigated. For different heats of 316LN SS containing 0.07-0.22 wt% nitrogen, the tensile and creep properties increased with increase in nitrogen content, while low cycle fatigue properties peaked at 0.14 wt% nitrogen. Finally, based on the evaluation of the hot cracking susceptibility of the different heats of 316LN SS with varying nitrogen content, using the Varestraint and Gleeble hot-ductility tests, the nitrogen content for the nitrogen-enhanced 316LN SS has been optimized at a level of 0.14 wt%. The 0.14 wt% nitrogen content in this optimised composition shifts the solidification mode of the weld metal to fully austenitic region, including that due to dilution of nitrogen from the base metal, thereby increasing its hot cracking susceptibility. This necessitated development and qualification of welding electrodes for obtaining weld metal with 0.14 wt% nitrogen by optimising the weld metal chemistry so as to obtain the requisite delta ferrite content, tensile properties, and very importantly impact toughness both in the as-welded and aged conditions. Studies on localised corrosion behaviour of nitrogen-enhanced 316LN SS indicated the beneficial effect of nitrogen addition to sensitization, pitting, intergranular corrosion, stress corrosion cracking and corrosion fatigue.

On the rôle of cavity nucleation in creep deformation and fracture

1983 ◽  
Vol 31 (10) ◽  
pp. 1537-1542 ◽  
Author(s):  
D.R. Hayhurst ◽  
W.A. Trampczynski ◽  
F.A. Leckie
Keyword(s):  
Creep Deformation ◽  
Cavity Nucleation ◽  
Deformation And Fracture

The Role of Filler Properties in the Creep Deformation of Filled Elastomers

1983 ◽  
Vol 56 (2) ◽  
pp. 465-480
Author(s):  
J. L. Thiele ◽  
R. E. Cohen
Keyword(s):  
Carbon Black ◽  
Creep Deformation ◽  
High Strain ◽  
Filled Elastomers ◽  
Filled Elastomer ◽  
Strain Mechanism ◽  
Sensitive Tool ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract The use of the creep T-jump experiment as a sensitive tool for elucidating the mechanistic behavior during the deformation of a complex material such as the carbon black filled elastomer has been illustrated. The activation energy for creep was determined as a function of stress for various vulcanizates. The effects of the choice of elastomer, and of variations in surface chemistry, structure, and loading of the filler, were studied. The T-jump results combined with electrical conductivity measurements confirmed the presence of a carbon black network which is considerably involved in the creep deformation process at low strain but not at high strain. In NR vulcanizates, there is a high-strain mechanism not observed in SBR vulcanizates; presumably strain-induced crystallization is responsible for the NR behavior. Oxidation of filler surfaces had essentially no effect on the creep deformation mechanisms, suggesting that, during creep, slippage of elastomers along the surface does not occur to any great extent for conventional or oxidized surfaces.

The Role of Grain Boundaries in Creep Deformation

1972 ◽  
Vol 6 (1) ◽  
pp. 189-194 ◽  
Author(s):  
T. Johannesson ◽  
A. Thölén
Keyword(s):  
Grain Boundaries ◽  
Creep Deformation
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