Thermodynamic Characteristics of Y2O3 and Y2S3 Nonmetallic Phase Formed in Liquid Steel

2020 ◽  
Vol 844 ◽  
pp. 9-23
Author(s):  
Sergii Gerasin ◽  
Dorota Kalisz ◽  
Jerzy Iwanciw
Keyword(s):  
Oxygen Content ◽  
Molten Steel ◽  
Liquid Steel ◽  
Thermodynamic Characteristics ◽  
Phase Precipitation ◽  
Low Oxygen ◽  
Metallic Oxide ◽  
Metal Bath ◽  
Metallic Inclusions ◽  
The Relationship

The current work deals the phenomenon of non-metallic inclusions as a result of the addition of Yttrium as an alloying component. The order of introducing individual components determines its final content in steel. This problem was analyzed using the WYK_Stal program developed at AGH-UST. Individual cases were considered using the accepted thermodynamics models based on Wagner’s formalism. The study of Y2O3 and Y2S3 phase precipitation and the relationship between the addition of Y, Al, Ca, O and S in molten steel was studied using the thermodynamic models. Based on the simulation, the authors stated that, the introduction of aluminum as the final deoxidizer into the liquid steel before the yttrium, results in the formation of non-metallic oxide inclusions. The low oxygen content in the metal bath promotes the formation of yttrium sulphide. In the case of calcium dosing, it is reasonable that, the yttrium is introduced after this element, which limits the losses on the formation of the yttrium sulphide phase.

scholarly journals Thermodynamic and kinetic simulation of Y2O3 and Y2S3 nonmetallic phase formation in liquid steel

2020 ◽  
Vol 56 (1) ◽  
pp. 11-25
Author(s):  
S. Gerasin ◽  
D. Kalisz ◽  
J. Iwanciw
Keyword(s):  
Oxygen Content ◽  
Phase Formation ◽  
Liquid Steel ◽  
Manganese Sulfide ◽  
Kinetic Simulation ◽  
Phase Precipitation ◽  
Low Oxygen ◽  
Metal Bath ◽  
Metallic Inclusions ◽  
The Relationship

The current work deals with the phenomenon of non-metallic inclusions as a result of the addition of yttrium to the liquid steel as an alloying component. The order of introducing individual components determines their final content in steel, and this problem was analyzed using the WYK_Stal program developed at AGH. The study of Y2O3 and Y2S3 phase precipitation and the relationship between the addition of Y, Al, Ca, O, and S in molten steel was studied using the thermodynamic models based on Wagner?s formalism. The introductions of yttrium prior to aluminum brought about huge losses, and it mainly occurred due to the formation of oxides. The low oxygen content in the metal bath promotes the formation of yttrium sulphide. When yttrium is introduced after aluminum and calcium, yttrium is used for the precipitation of its sulfide, and in this way the manganese sulfide formation is reduced.

scholarly journals Reoxidation of Al-Killed Steel by Cr2O3 from Tundish Cover Flux

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 554 ◽  
Author(s):  
Feng Wang ◽  
Daoxu Liu ◽  
Wei Liu ◽  
Shufeng Yang ◽  
Jingshe Li
Keyword(s):  
Experimental Study ◽  
Oxygen Content ◽  
Liquid Steel ◽  
Controlled Experiments ◽  
Low Oxygen ◽  
Total Oxygen ◽  
Total Oxygen Content

Reoxidation has long been a problem when casting ultra-low oxygen liquid steel. An experimental study of the reoxidation phenomenon caused by Cr2O3-bearing cover flux of Al-killed steel is presented here. MgO-CaO-SiO2-Al2O3-Cr2O3 tundish cover flux with various Cr2O3 contents were used to study the effects of Cr2O3 on total oxygen content (T[O]) and alumina and silicone loss of Al-killed steel at 1923 K (1650 °C). It was found that Cr2O3 can be reduced by Al to cause reoxidation, and the reaction occurs mainly within 2 to 3 min after the addition of the tundish cover flux with 5% and 10% Cr2O3 concentration. T[O] and Al loss increase with higher Cr2O3 concentration flux. Two controlled experiments were also made to investigate the oxygen transported to the steel by the decomposition of Cr2O3. It was calculated that when Al is present in steel, more than 90% of the reoxidation of Cr2O3 is caused by Al, and the rest is caused by decomposition.

Sampling liquid steel for oxygen content: A further evaluation of the bomb technique

JOM ◽  
1954 ◽  
Vol 6 (12) ◽  
pp. 1383-1385 ◽  
Author(s):  
S. Gilbert ◽  
G. R. Bailey
Keyword(s):  
Oxygen Content ◽  
Liquid Steel

Experience of Using Complex Modifiers to Increase Corrosion Resistance of Pipe Steels

2021 ◽  
Vol 316 ◽  
pp. 369-374
Author(s):  
Aleksey N. Shapovalov ◽  
Roman R. Dema ◽  
Sergey P. Nefed'ev
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth Metals ◽  
Test Results ◽  
Pipe Steels ◽  
Low Oxygen ◽  
Thermal Expansion Coefficients ◽  
Barium Strontium ◽  
Metallic Inclusions ◽  
Expansion Coefficients ◽  
Increase Corrosion Resistance

The article presents the test results of complex microcrystalline modifiers containing calcium, barium, strontium, rare earth metals. Complex modifiers were used in the processing of steel for 17G1S-U pipes in order to reduce its contamination with non-metallic inclusions, including corrosive ones. The use of modifiers allowed to reduce metal contamination by non-metallic inclusions of all kinds. The most experimental non-metallic inclusions were obtained during metal processing with INSTEEL®5.1 and INSTEEL®9.4 modifiers. In addition, the use of experienced modifiers ensured the production of complex oxysulfides of calcium, cerium and lanthanum with low oxygen content and thermal expansion coefficients, which increases the corrosion resistance of steel.

scholarly journals The Mineral Chemistry of Chlorites and Its Relationship with Uranium Mineralization from Huangsha Uranium Mining Area in the Middle Nanling Range, SE China

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 199 ◽  
Author(s):  
Dehai Wu ◽  
Jiayong Pan ◽  
Fei Xia ◽  
Guangwen Huang ◽  
Jing Lai
Keyword(s):  
Mining Area ◽  
Uranium Mining ◽  
Uranium Mineralization ◽  
Formation Mechanisms ◽  
Chemical Compositions ◽  
Type I ◽  
Low Oxygen ◽  
Nanling Range ◽  
The Relationship ◽  
Uranium Mining Area

The Huangsha uranium mining area is located in the Qingzhangshan uranium-bearing complex granite of the Middle Nanling Range, Southeast China. This uranium mining area contains three uranium deposits (Liangsanzhai, Egongtang, and Shangjiao) and multiple uranium occurrences, showing favorable mineralization conditions and prospecting potential for uranium mineral resources. Chloritization is one of the most important alteration types and prospecting indicators in this mining area. This study aims to unravel the formation environment of chlorites and the relationship between chloritization and uranium mineralization, based on detailed field work and petrographic studies of the wallrock and ore samples from the Huangsha uranium mining area. An electron probe microanalyzer (EPMA) was used in this study to analyze the paragenetic association, morphology, and chemical compositions of chlorite, to classify chemical types and to calculate formation temperatures and n(Al)/n(Al + Mg + Fe) values of chlorite. The formation mechanism and the relationship with uranium mineralization of the uranium mining area are presented. Some conclusions from this study are: (1) There are five types of chlorites, including the chlorite formed by the alteration of biotite (type-I), by the metasomatism of feldspar with Fe–Mg hydrothermal fluids (type-II), chlorite vein/veinlet filling in fissures (type-III), chlorite closely associated with uranium minerals (type-IV), and chlorite transformed from clay minerals by adsorbing Mg- and Fe-components (type-V). (2) The chlorite in the Huangsha uranium mining area belongs to iron-rich chlorite and is mainly composed of chamosite, partly clinochlore, which are the products of multiple stages of hydrothermal action. The original rocks are derived from argillite, and their formation temperatures vary from 195.7 °C to 283.0 °C, with an average of 233.2 °C, suggesting they formed under a medium to low temperature conditions. (3) The chlorites were formed under reducing conditions with low oxygen fugacity and relatively high sulfur fugacity through two formation mechanisms: dissolution–precipitation and dissolution–migration–precipitation; (4) The chloritization provided the required environment for uranium mineralization, and promoted the activation, migration, and deposition of uranium.

Research on the Realization of the Maximum Benefit of Thermal Power

2015 ◽  
Vol 713-715 ◽  
pp. 660-663
Author(s):  
Jia Min Chen
Keyword(s):  
Real Time ◽  
Oxygen Content ◽  
Thermal Power ◽  
Balance Method ◽  
Excess Air ◽  
Maximum Benefit ◽  
Function Expression ◽  
New Variables ◽  
The Relationship

First, Anti-balance method is used to build the model of q2,q3,q4 to figure out the Function expression of q2+q3+q4 .when q2+q3+q4 gets the minimum, the corresponded to the excess air ratio is the best excess air ratio. The excess air ratio is related to the load of boiler, so the function image describing the relationship between q2+q3+q4 and excess air ratio under the different load of 192.3MW, 215.8MW, 245.3MW and 298MW are made to get the best excess air ratio. Second, based on the model before, new variables q5 and q6 are added to complete the function formula of the efficiency and the excess air ratio, and four function image will be drew to show the tends. Finally, based on the conclusions above, smoke vents oxygen content can take the place of excess air ratio to achieve the purpose of monitoring the boiler in real time.

Effect of the Sintering Atmosphere on the Corrosion Resistance of Titanium for Application as Biomaterial

2012 ◽  
Vol 727-728 ◽  
pp. 85-89
Author(s):  
Luzinete P. Barbosa ◽  
Elki C. Souza ◽  
Lucio Salgado ◽  
I. Costa
Keyword(s):  
Corrosion Resistance ◽  
Oxygen Content ◽  
Passive Film ◽  
Titanium Surface ◽  
Sintered Titanium ◽  
Nacl Solution ◽  
Low Oxygen ◽  
Sintering Atmosphere ◽  
Corrosion Tests ◽  
Vacuum Atmosphere

In this work, the effect of sintering atmosphere on the corrosion resistance of sintered titanium has been evaluated in 0.9 % aqueous NaCl solution to simulate physiological environment. Corrosion tests were performed on titanium porous sintered under vacuum and vacuum plus dynamic argon. The results showed better passive properties associated to the titanium sintered under argon plus vacuum atmosphere than to the vacuum sintered titanium. The better corrosion resistance of the argon plus vacuum sintered titanium was attributed to the formation of a thin passive film on the titanium surface during sintering due the low oxygen content present in this atmosphere.

The oxygen content of the slag and the yield of liquid steel in blowing an open hearth bath with oxygen

Metallurgist ◽  
1971 ◽  
Vol 15 (8) ◽  
pp. 508-511
Author(s):  
A. I. Stroganov ◽  
B. L. Markov ◽  
A. G. Panchenko ◽  
A. A. Dobrokhotov
Keyword(s):  
Oxygen Content ◽  
Liquid Steel ◽  
Open Hearth
Sign in / Sign up

Export Citation Format

Share Document