Effect of Carbon Content on Transformation Structures of lron-22 Per Cent Nickel Alloys

2009 ◽  
pp. 250-250-12 ◽  
Author(s):  
J. R. Mihalisin
Keyword(s):  
Carbon Content ◽  
Nickel Alloys

Stress Corrosion Cracking Susceptibility Of Stainless Steels and Nickel-Base Alloys In Polythionic Acids and Acid Copper Sulfate Solution

CORROSION ◽  
1964 ◽  
Vol 20 (8) ◽  
pp. 256t-262t ◽  
Author(s):  
C. H. SAMANS
Keyword(s):  
Carbon Content ◽  
Copper Sulfate ◽  
Stainless Steels ◽  
Nickel Alloys ◽  
Temperature Limit ◽  
Low Carbon ◽  
Intergranular Cracking ◽  
Copper Sulfate Solution ◽  
Standard Acid ◽  
High Nickel

Abstract Intergranular cracking tendencies of fourteen stainless steels and two high-nickel alloys have been evaluated by exposing numerous specimens to polythionic acid and standard acid copper sulfate solutions. The sensitization curves for solution-annealed wrought stainless steels, which had been held for varying times at temperatures from 800 to 1700 F (427 to 927 C), had the same lower temperature limit for both solutions. The higher temperature limit for acid copper sulfate was significantly higher than for polythionic acid so the more standard acid copper sulfate test can be used for control. Decreasing the carbon content shifted the sensitization curve to longer times. Times in excess of 1000 to 4000 hours were required to sensitize steels stabilized with columbium or titanium. Molybdenum additions decrease the sensitization range, but the higher-carbon molybdenum-bearing stainless steels had an unexplained sensitization zone from 900 to 1000 F (482 to 538 C) for holding times exceeding 200 hours. The 25 percent Cr-Ni materials became sensitized over a narrower range of temperature than the plain 18 percent Cr-Ni alloys and, for a given carbon content, were more stable. If 1200 F (649 C) sensitizing followed thermal stabilization, the low-carbon Type 310 and Types 347 and 321 steels were sensitized the least. Two high-nickel alloys and a cast stainless steel failed when sensitized for 4 hours at 1200 F.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Bleaching ability of pre-hydrolyzed pulps in the context of a biorefinery mill

TAPPI Journal ◽  
2013 ◽  
Vol 12 (11) ◽  
pp. 49-53 ◽  
Author(s):  
CHRISTINE CHIRAT ◽  
LUCIE BOIRON ◽  
DOMINIQUE LACHENAL
Keyword(s):  
Carbon Content ◽  
Acid Hydrolysis ◽  
13C Nmr ◽  
Kraft Lignin ◽  
Kappa Number ◽  
Hydroxyl Groups ◽  
Kraft Pulps ◽  
Quaternary Carbon ◽  
Oxygen Delignification

Autohydrolysis and acid hydrolysis treatments were applied on mixed softwood chips. The cooking ability was studied by varying the alkali and duration of the cook. Pulps with kappa numbers varying from 30 to 70 were obtained. The bleaching ability of these pulps was studied and compared to control kraft pulps. The prehydrolyzed pulps were shown to be more efficiently delignified by oxygen than the control kraft pulps starting from the same kappa number. Furthermore, the final bleaching was also easier for these pulps. It was also shown that extensive oxygen delignification applied on high-kappa pre-hydrolyzed pulps could be a way to improve the overall yield, which is a prerequisite for the development of such biorefinery concepts. Lignin was isolated from the control kraft and the two pre-hydrolyzed kraft pulps and analyzed by 13C NMR. Lignins from pre-hydrolyzed kraft pulps had similar free phenolic groups content to the control kraft lignin, but their aliphatic hydroxyl groups and β-O-4 content were lower than for the control lignin. The quaternary carbon content was the same for all the samples.

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