Optimization of Ca Additions for Inclusion Modification

2019 ◽  
Author(s):  
Y. Pistorius ◽  
P. Kacar ◽  
B. Webler
Keyword(s):  
Inclusion Modification

Inclusion Modification by Al Deoxidation and Ca Treatment in Ti Containing 18%Cr Stainless Steel Melts

2013 ◽  
Vol 51 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Jong-Jin Pak ◽  
Kyung-Ho Kim ◽  
Won-Jin Choi ◽  
Sang-Beum Lee ◽  
Dong-Sic Kim
Keyword(s):  
Stainless Steel ◽  
Inclusion Modification

scholarly journals A Kinetic Model for the Modification of Al2O3 Inclusions during Calcium Treatment in High-Carbon Hard Wire Steel

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1305
Author(s):  
Zuobing Xi ◽  
Changrong Li ◽  
Linzhu Wang
Keyword(s):  
Kinetic Model ◽  
Early Stage ◽  
Morphological Evolution ◽  
Product Layer ◽  
Melting Time ◽  
Calcium Treatment ◽  
High Carbon ◽  
Inclusion Modification ◽  
Shrinking Core ◽  
Wire Steel

Laboratory-scale experiments for the modification of Al2O3 inclusions by calcium treatment in high-carbon hard wire steel were performed and the compositions and morphological evolution of inclusions were studied. The kinetics of the modification of Al2O3 inclusions by calcium treatment were studied in high-carbon hard wire steel based on the unreacted shrinking core model, considering the transfer of Ca and Al through the boundary layer and within the product layer, coupled with thermodynamic equilibrium at the interfaces. The diffusion of Al in the inclusion layer was the limiting link in the inclusion modification process. The Ca concentration in molten steel had the greatest influence on the inclusion modification time. The modification time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modification of Al2O3 into CA6 was fastest, while the most time was needed to modify CA into C12A7. It took about six times time longer at the later stage of inclusion modification than at the early stage. The complete modification time for inclusions increased with the square of their radii. The changes of CaO contents with melting time were estimated based on a kinetic model and was consistent with experimental results.

Theory and Experimental Research on Inclusion Modification in Improved Carbon Structural Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1659-1666
Author(s):  
Cai Jun Zhang ◽  
Li Guang Zhu ◽  
Dong Mei Tu ◽  
Shuo Ming Wang ◽  
Hui Ding
Keyword(s):  
Carbon Steel ◽  
Experimental Research ◽  
Calcium Treatment ◽  
Sulfur Activity ◽  
High Quality ◽  
Steel Temperature ◽  
Aluminum Activity ◽  
Molten Steel Temperature ◽  
Inclusion Modification ◽  
Carbon Structural Steel

By means of the thermodynamics analysis of inclusion modification in the process of calcium treatment, and the advantage area chart of calcium, aluminum, sulfur, oxygen activity in inclusion midification, this paper analyzes the effects of molten steel temperature, aluminum activity, sulfur activity and other factors on inclusion modification. After calcium treatment, inclusions in high-quality carbon steel S48 will become massive or globular calcium aluminate, MnS inclusion and the composite inclusions of MgO·Al2O3 in kernel and CaO·Al2O3 in shell.

scholarly journals Inclusion Modification in C104Cr Saw Wire Steel with Different Cerium Content

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 54 ◽  
Author(s):  
Yang Li ◽  
Meng Sun ◽  
Zhouhua Jiang ◽  
Changyong Chen ◽  
Kui Chen ◽  
...  
Keyword(s):  
Beneficial Effect ◽  
Size Distribution ◽  
Sulfur Content ◽  
Outer Layer ◽  
Distribution Diagram ◽  
Metallographic Examination ◽  
Cerium Content ◽  
Inclusion Modification ◽  
Wire Steel ◽  
Element Mapping

In the present study, the effect of cerium content in the range of 0~0.0676% on oxygen and sulfur content, as well as the quantity, size, distribution, and type of inclusions in C104Cr saw wire steel, were investigated using thermodynamic analysis, metallographic examination, SEM-EDS, and component analysis. The results showed that conducting a vacuum carbon pre-deoxidization process is helpful in preventing the formation of Ce2O3 inclusions in a smelting experiment, and cerium has a beneficial effect in terms of modifying inclusions. When the content of cerium in steel is 0.0136% or 0.0277%, the main inclusions in the steel are Ce2O2S and CeS, and when the content of cerium is 0.0389% or above, the inclusions in the steel are Ce2O2S, CeS, Ce–S–O–P(As), Ce–O–P, and Ce–P(As). The calculation of the segregation model showed that the precipitation of CeP and CeAs in steel takes place at the end of solidification. According to the element mapping distribution diagram of Ce–S–O–P(As) and the layered Ce–O–P inclusions found in steel with high cerium content, two possible mechanisms for the formation of Ce2O3 inclusions distributed in the outer layer of cerium composite inclusions are proposed. The first mechanism suggests that Ce2O3 inclusions are generated from the combination of [Ce] and [O] directly, and the second suggests that Ce2O3 is the product of an oxidization reaction after the formation of CeP.

scholarly journals Effect of Zr Additions on Non-Metallic Inclusions in X11CrNiMo12 Steel

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1183
Author(s):  
Jaka Burja ◽  
Mitja Koležnik ◽  
Barbara Šetina Batič ◽  
Jožef Medved
Keyword(s):  
Martensitic Steel ◽  
Inclusion Size ◽  
Reaction Products ◽  
Clean Steel ◽  
Metallic Inclusions ◽  
Inclusion Modification ◽  
Steel Cleanliness ◽  
Steel Grades ◽  
Al Additions ◽  
Deoxidation Practice

The production of clean steel is associated with high-quality steel grades for demanding applications. The formation of oxide inclusions mainly depends on the deoxidation practice; it is usually carried out through Al additions, but alumina inclusions can have detrimental effects. An alternative zirconium inclusion modification was used in a creep-resistant steel to improve the cleanliness of laboratory-made steel. The thermodynamics behind the inclusion modification are presented, the reaction products are identified and the steel cleanliness improvement is quantified. The resulting influence of zirconium addition on non-metallic inclusions and mechanical properties is discussed. While the Zr additions drastically reduce the non-metallic inclusion size and area, additions above a certain amount result in the formation of zirconium nitrides that ultimately soften the martensitic steel due to the depletion of nitrogen in solid solution.

scholarly journals Inclusion Modification in Si–Mn Killed Steels using Titanium Addition

2015 ◽  
Vol 55 (1) ◽  
pp. 190-199 ◽  
Author(s):  
Vivek Thapliyal ◽  
Abhishek Kumar ◽  
David Robertson ◽  
Jeffrey Smith
Keyword(s):  
Titanium Addition ◽  
Inclusion Modification

Thermodynamic examination of inclusion modification and precipitation from calcium treatment to solidified steel

2003 ◽  
Vol 30 (2) ◽  
pp. 111-115 ◽  
Author(s):  
L. Holappa ◽  
M. Hämäläinen ◽  
M. Liukkonen ◽  
M. Lind
Keyword(s):  
Calcium Treatment ◽  
Inclusion Modification
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