332. Studied of liquid steel degassing in the ladke placed in a vacuum chamber

Vacuum ◽  
1968 ◽  
Vol 18 (2) ◽  
pp. 105
Keyword(s):  
Liquid Steel ◽  
Vacuum Chamber ◽  
Steel Degassing

scholarly journals Splashing Simulation of Liquid Steel Drops during the Ruhrstahl Heraeus Vacuum Process

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1070
Author(s):  
Zhi-jian Zhao ◽  
Min Wang ◽  
Lei Song ◽  
Yan-ping Bao
Keyword(s):  
Pressure Drop ◽  
Liquid Steel ◽  
Industrial Production ◽  
Vacuum Chamber ◽  
Early Stage ◽  
Vacuum Treatment ◽  
Coupling Model ◽  
Liquid Level ◽  
Vacuum Pressure ◽  
Discrete Phase Model

In view of the serious splashing problem in the 120 ton Ruhrstahl Heraeus (RH) refining process of a special steel company, a coupling model of volume of fluid + discrete phase model was established to study the influence of the vacuum pressure drop mode on the RH vacuum splashing. Three different pressure drop modes were simulated, and the splash situation was described by the fluctuation of the liquid level and the velocity field in the vacuum chamber in this model. The model predicted that the most serious splashing situation of liquid drops would happen at the early stage of vacuum treatment, which was consistent with that found in industrial production. The liquid level in the vacuum chamber maintained a low fluctuation at the late stage of the RH vacuum process. The vacuum pressure drop mode was closely relevant with the splashing situation. The splashing of liquid steel can be effectively improved by controlling the vacuum pressure drop mode, and it can be used in the industrial production situation.

scholarly journals Research regarding the vacuuming of liquid steel on steel degassing

2018 ◽  
Vol 294 ◽  
pp. 012005
Author(s):  
M Magaon ◽  
M Radu ◽  
S Şerban ◽  
L Zgripcea
Keyword(s):  
Liquid Steel ◽  
Steel Degassing

scholarly journals The Research of Low-Oxygen Control and Oxygen Behavior during RH Process in Silicon-Deoxidization Bearing Steel

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 812 ◽  
Author(s):  
Wei Xiao ◽  
Min Wang ◽  
Yanping Bao
Keyword(s):  
Mass Transfer ◽  
Liquid Steel ◽  
Vacuum Chamber ◽  
High Vacuum ◽  
Bearing Steel ◽  
Smelting Process ◽  
Oxygen Mass Transfer ◽  
Oxygen Control ◽  
Rh Process ◽  
Top Slag

The variation of total oxygen (T.O) content, characterization of inclusions, slag composition, and off-gas behavior during the smelting process of silicon-deoxidization bearing steel were investigated with industrial experiments. The change of content of combined oxygen during RH (Ruhrstahl–Hereaeus vacuum degassing furnace) process was calculated and compared with T.O content change. It is found that the decrease of oxygen content is mainly caused by the removal of dissolved oxygen rather than the removal of oxides during RH process. Carbon was found to be a strong deoxidizer (stronger than aluminum) in high vacuum degree. Top slag is an oxygen source of the deoxidization process, leading to the re-oxidization of liquid steel, even though the FeO content is low in top slag. During the RH process, the change of oxygen mainly exists in three processes: 1) Deoxidization reaction in vacuum chamber, 2) oxygen mass transfer process between liquid steel out from a vacuum chamber and in ladle, and 3) oxygen mass transfer between ladle slag and liquid steel. It depends mainly on the mass transfer of the oxygen in the liquid steel.

scholarly journals Physical Modelling Of The Steel Flow In RH Apparatus

2015 ◽  
Vol 60 (3) ◽  
pp. 1859-1864 ◽  
Author(s):  
J. Pieprzyca ◽  
T. Merder ◽  
M. Saternus ◽  
K. Michalek
Keyword(s):  
Physical Model ◽  
Vacuum Chamber ◽  
Physical Modelling ◽  
Inert Gas ◽  
Hydrodynamic Conditions ◽  
Case Methods ◽  
Hydrodynamic Processes ◽  
Industrial Unit ◽  
Steel Degassing ◽  
Steel Flow

Abstract The efficiency of vacuum steel degassing using RH methods depends on many factors. One of the most important are hydrodynamic processes occurring in the ladle and vacuum chamber. It is always hard and expensive to determine the flow character and the way of steel mixing in industrial unit; thus in this case, methods of physical modelling are applied. The article presents the results of research carried out on the water physical model of RH apparatus concerning the influence of the flux value of inert gas introduced through the suck legs on hydrodynamic conditions of the process. Results of the research have visualization character and are presented graphically as a RTD curves. The main aim of such research is to optimize the industrial vacuum steel degassing process by means of RH method.

Thin Pyrolytic Graphite Films for Electron Microscope Substrates

1971 ◽  
Vol 29 ◽  
pp. 226-227 ◽  
Author(s):  
George H. N. Riddle ◽  
Benjamin M. Siegel
Keyword(s):  
Vacuum Chamber ◽  
Pyrolytic Graphite ◽  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Graphite Substrate ◽  
Nickel Substrate ◽  
Routine Procedure ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A routine procedure for growing very thin graphite substrate films has been developed. The films are grown pyrolytically in an ultra-high vacuum chamber by exposing (111) epitaxial nickel films to carbon monoxide gas. The nickel serves as a catalyst for the disproportionation of CO through the reaction 2C0 → C + CO2. The nickel catalyst is prepared by evaporation onto artificial mica at 400°C and annealing for 1/2 hour at 600°C in vacuum. Exposure of the annealed nickel to 1 torr CO for 3 hours at 500°C results in the growth of very thin continuous graphite films. The graphite is stripped from its nickel substrate in acid and mounted on holey formvar support films for use as specimen substrates.The graphite films, self-supporting over formvar holes up to five microns in diameter, have been studied by bright and dark field electron microscopy, by electron diffraction, and have been shadowed to reveal their topography and thickness. The films consist of individual crystallites typically a micron across with their basal planes parallel to the surface but oriented in different, apparently random directions about the normal to the basal plane.

New replica method with plasma polymerized film by glow discharge

1988 ◽  
Vol 46 ◽  
pp. 414-415
Author(s):  
A. Tanaka ◽  
M. Yamaguchi ◽  
T. Hirano
Keyword(s):  
Power Supply ◽  
Plasma Polymerization ◽  
Vacuum Chamber ◽  
Complex Surface ◽  
Replica Method ◽  
Metal Extraction ◽  
High Voltage Power Supply ◽  
Negative Glow ◽  
Hydrocarbon Gas ◽  
Hydrocarbon Molecules

The plasma polymerization replica method and its apparatus have been devised by Tanaka (1-3). We have published several reports on its application: surface replicas of biological and inorganic specimens, replicas of freeze-fractured tissues and metal-extraction replicas with immunocytochemical markers.The apparatus for plasma polymerization consists of a high voltage power supply, a vacuum chamber containing a hydrocarbon gas (naphthalene, methane, ethylene), and electrodes of an anode disk and a cathode of the specimen base. The surface replication by plasma polymerization in negative glow phase on the cathode was carried out by gassing at 0.05-0.1 Torr and glow discharging at 1.5-3 kV D.C. Ionized hydrocarbon molecules diffused into complex surface configurations and deposited as a three-dimensionally polymerized film of 1050 nm in thickness.The resulting film on the complex surface had uniform thickness and showed no granular texture. Since the film was chemically inert, resistant to heat and mecanically strong, it could be treated with almost any organic or inorganic solvents.

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