Thermodyanmics of CaO in Slag Reduced by Carbon during VD Process of Hollow Steel 95CrMo and its Effect on Inclusions

2014 ◽  
Vol 788 ◽  
pp. 289-297 ◽  
Author(s):  
Chuan Jie Cai ◽  
Shao Bo Zheng ◽  
Jing Chen ◽  
Zhi Yang Ye ◽  
Hui Gai Li ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Liquid Steel ◽  
Treatment Process ◽  
Regular Solution Model ◽  
Slag Basicity ◽  
Smelting Process ◽  
Steel Temperature ◽  
Vacuum Degree ◽  
Thermodynamic Conditions ◽  
Steel Refining

With the help of thermodynamics calculation and kinetic model, the generation mechanism of calcium aluminate inclusions in hollow steel 95CrMo was analyzed. The steel was produced in a certain steelmaking factory whose smelting process is EAF-LF-VD-CC and the micreostructure of the hollow steel 95CrMo samples have been investigated by SEM and EDS. Based on Lumsden’s regular solution model to molten slags, the possibility of CaO in slags reduced by carbon during hollow steel refining in VD furnace was calculated. The influence of furnace vacuum, slag basicity and liquid steel temperature on the reduction of CaO in slag by carbon was discussed. It was showed that the carbon dissolving in liquid steel might reduce CaO in slags to dissolved calcium which could also react with Al2O3 and turn into dot calcium-aluminate inclusions in the steel. The calcium-aluminate existing in the hollow steel easily turned into dot inclusions, which would decrease the fatigue life of the hollow steel. According to the thermodynamic conditions of dot calcium-aluminate inclusions, the influence of slag basicity, temperature of liquid steel, vacuum degree and the Ca treatment process on the quantity of dot inclusions in hollow steel 95CrMo was analyzed.

Aluminum Plasma Dross Treatment Process and Calcium Aluminate Production: Closing the Loop with No Residue

2013 ◽  
pp. 1183-1194
Author(s):  
Raymond Breault ◽  
Daniel Guay ◽  
Ghyslain Dubé ◽  
Denis Legault ◽  
Ronald Morin ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Treatment Process ◽  
Aluminum Plasma ◽  
Closing The Loop

Thermodynamic Analysis of Liquid Steel Refining by Complex La–Ce–Al-Based Alloy

2020 ◽  
Vol 50 (4) ◽  
pp. 234-242
Author(s):  
G. G. Mikhailov ◽  
L. A. Makrovets ◽  
O. V. Samoilova
Keyword(s):  
Thermodynamic Analysis ◽  
Liquid Steel ◽  
Steel Refining

Simulation of Oxygen and Nitrogen Removal from Steel by Means of Titanium and Aluminum

2011 ◽  
Vol 56 (3) ◽  
pp. 635-644 ◽  
Author(s):  
J. Iwanciw ◽  
D. Podorska ◽  
J. Wypartowicz
Keyword(s):  
Chemical Composition ◽  
Computer Program ◽  
Titanium Oxide ◽  
Nitrogen Removal ◽  
Liquid Steel ◽  
Variable Temperature ◽  
Metallic Phase ◽  
Parallel Analysis ◽  
Titanium Nitrides ◽  
Steel Refining

Simulation of Oxygen and Nitrogen Removal from Steel by Means of Titanium and Aluminum Authors' computer program was employed in the simulation of the course of steel refining by means of simultaneously used aluminium and titanium. The mass and chemical composition of liquid steel and non-metallic precipitates, were calculated at constant or variable temperature. The influence of assumed nitrides form on the results of simulation was determined. Nitrides may be considered either as separate phases or as the components of non-metallic solution. The stoichiometry of titanium oxide obtained also influences the results of simulation. Parallel analysis of steel refining was carried out with the use of FactSage program. As a result of calculations the subsequent states of equilibrium between steel and non-metallic phase were determined. It was found that aluminium and titanium nitrides may exist only as the components of oxide-nitride solution, not as separate phases.

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.

The Influence of Slenderness Ratios of Multi-Hole Ceramic Filters from SF - 1.67 to SF - 8.36 of Filter Surface on Efficiency of Liquid Steel Refining from Non-Metallic Phase

2013 ◽  
Vol 212 ◽  
pp. 205-208 ◽  
Author(s):  
Krystian Janiszewski ◽  
Bożena Gajdzik ◽  
Andrzej Wyciślik
Keyword(s):  
Liquid Steel ◽  
Slenderness Ratio ◽  
Filter Material ◽  
Metallic Phase ◽  
Ceramic Filter ◽  
Process Efficiency ◽  
Ceramic Filters ◽  
Filter Surface ◽  
Theoretical Assumptions ◽  
Steel Refining

We propose in this publication the introduction of new, additional definition describing the multiple orifice ceramic filters used in research works on the liquid steel filtrations, calling this the filter slenderness ratio. In order to confirm the theoretical assumptions we have performed a series of the laboratory scale experiments (for the filter slenderness ratio SF - 1.67 to SF - 8.36). The influence of the filter slenderness on the filtration process efficiency has been determined through variations in quantities and surface shares of the non-metallic phase in the filtrated steel in relation to the non-filtered steel. We present also the results of researches on the separating surfaces between the liquid steel and the ceramic filter material, which in form of photos and scanning microscope microanalyses are put together in the publication.

scholarly journals Thermodynamic analysis of liquid steel refining by complex alloy containing La - Ce -Al

2020 ◽  
Vol 63 (3-4) ◽  
pp. 238-247
Author(s):  
G. G. Mikhailov ◽  
L. A. Makrovets ◽  
O. V. Samoilova
Keyword(s):  
Thermodynamic Analysis ◽  
Liquid Steel ◽  
Complex Alloy ◽  
Steel Refining
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