Precipitation of aluminum nitride in a high strength maraging steel with low nitrogen content

2014 ◽  
Vol 98 ◽  
pp. 193-201 ◽  
Author(s):  
G. Jeanmaire ◽  
M. Dehmas ◽  
A. Redjaïmia ◽  
S. Puech ◽  
G. Fribourg
Keyword(s):  
Aluminum Nitride ◽  
Nitrogen Content ◽  
Maraging Steel ◽  
High Strength ◽  
Low Nitrogen

Deep Denitrogenization Technology of 23Co-Ni Steel in Vacuum Induction Melting Furnace

2014 ◽  
Vol 1004-1005 ◽  
pp. 227-230
Author(s):  
Rui Wang ◽  
Hui Shu Zhang ◽  
Lei Tang ◽  
Dong Ping Zhan ◽  
Zhou Hua Jiang ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Melting Furnace ◽  
High Strength ◽  
Electromagnetic Stirring ◽  
Vacuum Induction Melting ◽  
Melting Time ◽  
Induction Melting ◽  
Ultra High Strength Steel ◽  
Nitrogen Contents ◽  
Low Nitrogen

23Co-Ni is an ultra-high strength steel and it needs ultra low nitrogen content in the steel. The removal of nitrogen for 23Co-Ni steel in a 6t/12t Vacuum Induction Melting Furnace (VIM) with different melting processes was studied. The results show that, the longer of the melting time and the higher of the vacuum level, the lower of the final nitrogen contents is. The denitrogenization rate can reach 70% when the melting time is more than 8 hours. The electromagnetic stirring can increase the denitrogenization speed. When the VIM is vacuumed to 1-3 Pa, it can make the nitrogen content reaches 0.0005%-0.0008%.

Microstructure of resistance spot welding of maraging steels

1990 ◽  
Vol 48 (4) ◽  
pp. 900-901
Author(s):  
I. Neuman ◽  
S.F. Dirnfeld ◽  
I. Minkoff
Keyword(s):  
Maraging Steel ◽  
Spot Welding ◽  
Lath Martensite ◽  
Base Material ◽  
Aging Treatment ◽  
High Strength ◽  
Maraging Steels ◽  
Heat Treated ◽  
Current Cycle ◽  
Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

Effect of nitrogen on transformation behavior and intragranular ferrite formation in a V–Ti microalloyed steel for forging

2018 ◽  
Vol 115 (3) ◽  
pp. 311 ◽  
Author(s):  
Ningbo Zhou ◽  
Fan Zhao ◽  
Yiqun Liu ◽  
Bo Jiang ◽  
Chaolei Zhang ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Volume Fraction ◽  
Microalloyed Steel ◽  
High Strength ◽  
Transformation Behavior ◽  
Ferrite Formation ◽  
High Toughness ◽  
Intragranular Ferrite ◽  
Production Experiment ◽  
Cct Diagrams

The transformation behavior and intragranular ferrite formation in V–Ti microalloyed steel with a nitrogen content of 0.005 wt.% and 0.015 wt.% are studied by the DIL 805A dilatometer. The results show that increasing the nitrogen content has no significant effect on AC1, AC3and MStemperature. However, the continuous cooling transformation (CCT) diagrams are shifted to left side. The minimum cooling rates of bainitc and martensitic transformation are increased from 3 °C/s to 5 °C/s and from 5 °C/s to 10 °C/s, respectively. (Ti, V)(C, N) particles on MnS is the nuclei of intragranular ferrite, and (1 0 0)(Ti, V)(C, N)and (1̅ 0 1̅α) are just misoriented by 6.7°. With the increase of nitrogen content, the number of intragranular ferrite is increased from 73 to 170 per · mm2. The volume fraction of intragranular ferrite is increased from 0.23%∼0.79% to 0.79%∼4.6% at cooling rate of 1 °C/s∼0.1 °C/s. According to the industrial production experiment, the toughness of forging crankshaft is improved by increasing the nitrogen content. It is benefit for achieving fair matching of high strength and high toughness of crankshaft.

NOx Reduction Review on Fuel Alternative in Cement Kiln

2013 ◽  
Vol 864-867 ◽  
pp. 1626-1629
Author(s):  
Hai Bing Liu ◽  
Xiao Dong Chen ◽  
Jun Gu
Keyword(s):  
Nitrogen Content ◽  
Fossil Fuels ◽  
Nox Reduction ◽  
Reducing Agent ◽  
Environmental Benefits ◽  
Nox Emission ◽  
Cement Kiln ◽  
Cement Kilns ◽  
Low Nitrogen

The paper first discusses the relativity between alternative combustion andNOx emissions by a test in dry cement kiln, and a lot of case on fuel alternative The main findings of the study are that the use of RDF in cement kilns instead of coal or coke offers environmental benefits and reduce NOx emission. The conclusion is that the NOx generation can probably be lower because of lower flame temperatures or lower air excess and low nitrogen content in comparison with fossil fuels also is impartment reason., another a fact that most of the nitrogen (N) in biomass is released as ammonia (NH3) which acts as a reducing agent with NOx to form nitrogen (N2).

scholarly journals Pyrolysis of Furfural Residues and Possible Utilization Pathway

2021 ◽  
Author(s):  
George Ngusale
Keyword(s):  
Nitrogen Content ◽  
Minor Component ◽  
Pure Nitrogen ◽  
Thermogravimetric Analyzer ◽  
Furfural Residues ◽  
Furfural Residue ◽  
Ftir Spectrometer ◽  
A Minor ◽  
Utilization Pathway ◽  
Low Nitrogen

The manuscript attempts to understand the evolution of NOx precursors: NH3 and HCN from Pyrolysis of furfural residue (FR). The pyrolysis process was carried out in a thermogravimetric analyzer (TGA) coupled to Fourier-transform infrared (FTIR) spectrometer. The combination revealed insightful information on the evolution of NH3 and HCN. This could help us better understand the characteristics of FR derived from furfural production especially with regard to NH3 and HCN. Nitrogen is considered a minor component in biomass wastes; in this study nitrogen content is about 0.57%. However, the pollution potential poised by low nitrogen content is huge through both direct and indirect processes. Thus, this study presents results that were found with regard to FR pyrolysis in pure nitrogen environment. At the heating rate of 40°C/min−1, the only NOx precursor detected was HCN at 713 cm−1 as per the database provided by National Institute of Standards and Technology (NIST). NH3 was not detected. The particle size of FR used ranged between 0.15–0.25 mm.

The influence of diet on the nitrogenous components passing to the duodenum and through the lower ileum of sheep

1966 ◽  
Vol 166 (1002) ◽  
pp. 63-79 ◽  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Nitrogen Content ◽  
Aspartic Acid ◽  
Total Nitrogen ◽  
Amino Nitrogen ◽  
Terminal Part ◽  
High Nitrogen ◽  
Low Nitrogen ◽  
Lower Ileum

Analyses of the alimentary contents flowing to the duodenum of sheep during 24 h show that when the sheep are consuming a low-nitrogen diet more total nitrogen and amino nitrogen pass to the duodenum than are eaten daily in the food whereas when the sheep are eating high nitrogen diets, less total nitrogen and less amino nitrogen pass to the duodenum. The disparity between the total nitrogen and amino nitrogen content of the diets largely disappeared by the time the alimentary contents reached the terminal part of the ileum. From 64 to 68% of the nitrogen entering the duodenum and 54 to 64% of the nitrogen in the ileal contents was in the form of amino nitrogen. Proportionately more of the amino nitrogen was in solution in the ileal contents than in the duodenal contents. Losses of amino acids in the stomach when a high-nitrogen diet was consumed were especially large for glutamic acid, aspartic acid, proline, arginine and leucine. They were least for cystine and threonine. Gains of amino acids in the stomach when low nitrogen diets were consumed were all substantial except for proline, where a loss was found when hay and flaked maize were given. When these changes are considered as proportions of the quantities eaten then trends are similar for all acids. Changes in the molar proportions of the amino acids present in hydrolysates of the duodenal and ileal contents are discussed together with the significance of these changes in relation to the nutrition of the sheep.

Hydrogen embrittlement of ultra high strength 300 grade maraging steel

2015 ◽  
Vol 101 ◽  
pp. 12-18 ◽  
Author(s):  
L.P.M. Santos ◽  
M. Béreš ◽  
I.N. Bastos ◽  
S.S.M. Tavares ◽  
H.F.G. Abreu ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Maraging Steel ◽  
High Strength

Comparison of Microstructure and Mechanical Properties of Additively Manufactured and Conventional Maraging Steel

2020 ◽  
Vol 405 ◽  
pp. 133-138
Author(s):  
Ludmila Kučerová ◽  
Andrea Jandová ◽  
Ivana Zetková
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Precipitation Hardening ◽  
High Strength ◽  
Hardness Measurement ◽  
Nickel Steel ◽  
Heat Treated ◽  
Good Material ◽  
Iron Nickel

Maraging steel is an iron-nickel steel alloy, which achieves very good material properties like high toughness, hardness, good weldability, high strength and dimensional stability during heat treatment. In this work, maraging steel 18Ni-300 was manufactured by selective laser melting. It is a method of additive manufacturing (AM) technology, which produces prototypes and functional parts. Sample of additively manufactured and conventional steel with the same chemical composition were tested after in three different states – heat treated (as-built/as-received), solution annealed and precipitation hardened. Resulting microstructures were analysed by light and scanning electron microscopy and mechanical properties were obtained by hardness measurement and tensile test. Cellular martensitic microstructures were observed in additively manufactured samples and conventional maraging steel consisted of lath martensitic microstructures. Very similar mechanical properties were obtained for both steels after the application of the same heat treatment. Ultimate tensile strengths reached 839 – 900 MPa for samples without heat treatment and heat treated by solution annealing, the samples after precipitation hardening had tensile strengths of 1577 – 1711 MPa.

Simultaneous yeast–bacteria inoculum. A feasible solution for the management of oenological fermentation in red must with low nitrogen content

2012 ◽  
Vol 63 (2) ◽  
pp. 805-808 ◽  
Author(s):  
Raffaele Guzzon ◽  
Tomas Roman Villega ◽  
Michele Pedron ◽  
Mario Malacarne ◽  
Giorgio Nicolini ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Feasible Solution ◽  
Low Nitrogen
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