Strong effect of carbides and alloy elements in gradient nanostructured 32Cr2Mo1VE steel on nitrogen atom diffusion

2021 ◽  
pp. 111274
Author(s):  
Sai Cai ◽  
Jinquan Sun ◽  
Yanpeng Xue ◽  
Qingkun He ◽  
Jie Huan ◽  
...  
Keyword(s):  
2014 ◽  
Vol 82 ◽  
pp. 107-113 ◽  
Author(s):  
Xuan Hu ◽  
Rui Tu ◽  
Jianhong Wei ◽  
Chunxu Pan ◽  
Jindong Guo ◽  
...  

Author(s):  
G.J.C. Carpenter

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.


2008 ◽  
Vol 128 (10) ◽  
pp. 615-618 ◽  
Author(s):  
Takeshi Kitajima ◽  
Akihiro Kubota ◽  
Toshiki Nakano

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).


Synlett ◽  
2020 ◽  
Author(s):  
Yoshihiro Ueda ◽  
Gong Chen ◽  
Kenta Arai ◽  
Kazuhiro Morisaki ◽  
Takeo Kawabata

AbstractA method for dirhodium-catalyzed C(sp3)–H amidation of N,N-dimethylanilines was developed. Chemoselective C(sp3)–H amidation of N-methyl group proceeded exclusively in the presence of C(sp2)–H bonds of the electron-rich aromatic ring. Site-selective C(sp3)–H amidation proceeded exclusively at the N-methyl group of N-methyl-N-alkylaniline derivatives with secondary, tertiary, and benzylic C(sp3)–H bonds α to a nitrogen atom.


2002 ◽  
Vol 43 (28) ◽  
pp. 4963-4968 ◽  
Author(s):  
Reynald Deléens ◽  
Arnaud Gautier ◽  
Serge R Piettre

1993 ◽  
Vol 48 (11) ◽  
pp. 1613-1620 ◽  
Author(s):  
Helmut Fischer ◽  
Claudia Kalbas ◽  
Carsten Troll ◽  
Klaus H. Fluck

Pentacarbonyl(thietane)tungsten complexes react with thiocyanate, [SCN]-, and SiO2/H2O by insertion of the CN group into a S—C bond of the four-membered heterocycle, 1,3-migration of the pentacarbonyltungsten fragment and protonation of the nitrogen atom to give tungsten-coordinated thiazinthione complexes. Analogously, the reactions of a thietane tungsten complex with [SeCN]- and SiO2/H2O affords a thiazinselone complex. A selenazinthione complex is obtained from a selenetane complex and [SCN]- (+ SiO2/H2O). The insertions are regiospecific and stereoselective. The structure of the trans-isomer of a pentacarbonyl-(thiazinthione) complex has been established by X-ray structure analysis.


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