Several Rating Methods of Nonmetallic Inclusions in Bearing Steels in Japan

2009 ◽  
pp. 22-22-16 ◽  
Author(s):  
A Koyanagi ◽  
M Kinoshi
Keyword(s):  
Nonmetallic Inclusions ◽  
Bearing Steels

Corrosive Damage Close to Nonmetallic Inclusions in Bearing Steels

2018 ◽  
Vol 48 (3) ◽  
pp. 197-201
Author(s):  
S. I. Gubenko ◽  
A. B. Sychkov ◽  
E. V. Parusov ◽  
A. I. Denisenko ◽  
A. N. Zavalishchin
Keyword(s):  
Nonmetallic Inclusions ◽  
Bearing Steels

Electron Microscopy of Stress-Induced Structural Alterations Near Inclusions in Bearing Steels

1966 ◽  
Vol 88 (3) ◽  
pp. 568-571 ◽  
Author(s):  
John L. O’Brien ◽  
Alwyn H. King
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nonmetallic Inclusions ◽  
Cell Formation ◽  
Small Cell ◽  
Structural Alterations ◽  
Bearing Steels ◽  
Thin Foils ◽  
Transmission Electron ◽  
Small Cell Size

The white-etching structural alteration occurring around nonmetallic inclusions in cyclically stressed bearing steels has been studied by transmission-electron microscopy. In order to use this method, thin foils have been prepared with an edge running through the alteration. It has been found that the alteration is due to the formation of 0.05 to 0.1-micron cells in ferrite. The cell formation is similar to that seen in fatigued iron except for the small cell size of the deformed steel. Evidence is also given that deformation causes breakup of the carbides produced on the tempering of steel prior to deformation.

scholarly journals Effect of the Al2O3 Content in the Slag on the Chemical Reactions and Nonmetallic Inclusions during Electroslag Remelting

2020 ◽  
Vol 51 (5) ◽  
pp. 1904-1911 ◽  
Author(s):  
Reinhold S. E. Schneider ◽  
Manuel Molnar ◽  
Gerald Klösch ◽  
Christopher Schüller
Keyword(s):  
Chemical Composition ◽  
Service Life ◽  
Nonmetallic Inclusions ◽  
Roller Bearing ◽  
Bearing Steel ◽  
Electroslag Remelting ◽  
Al2o3 Content ◽  
Spinel Type ◽  
Bearing Steels ◽  
Equilibrium Reactions

Abstract The service life of roller bearings is extremely sensitive to large and hard nonmetallic inclusions (NMIs), requesting the highest standards in their production. To determine the metallurgical possibilities, the effect of Al2O3 contents between 0 and 33 pct in the remelting slag was investigated by remelting a roller bearing steel in an experimental electroslag remelting (ESR) plant. Thereby, changes in the chemical composition of the materials (electrode vs ingots) and in the remelting slag during remelting, as well as the amount and composition of the NMIs prior to and after remelting, were investigated. Changes in the chemical composition can largely be explained by equilibrium reactions between the slag and the metal, thereby low Al contents in the remelted materials could only be achieved with the lowest Al2O3 contents in the slag. Furthermore, higher Al2O3 contents in the slag also lead to higher oxygen and sulfur contents in the steel as well as higher amounts of NMIs after remelting. The composition of the NMIs changed from alumina type for high Al2O3 contents to spinel type and other mixed MgO-SiO2 oxides for low Al2O3 contents. The results indicate solutions for the production of bearing steels with the lowest amounts of undesired large and hard NMIs.

Quality of bearing steels melted by current methods and with off-furnace treatment with respect of nonmetallic inclusions, gases, and impurities

2008 ◽  
Vol 50 (7-8) ◽  
pp. 331-337
Author(s):  
L. K. Orzhitskaya ◽  
Ya. I. Spektor ◽  
E. A. Shchugul’naya ◽  
A. V. Zhaivoronok
Keyword(s):  
Nonmetallic Inclusions ◽  
Bearing Steels ◽  
Furnace Treatment

Regarding the mechanism of formation of nonmetallic inclusions conglomerates of system Al2O3-MgO

2019 ◽  
Vol 75 (12) ◽  
pp. 1341-1351
Author(s):  
A. A. Safronov ◽  
V. S. Dub ◽  
V. V. Orlov ◽  
K. L. Kosyrev ◽  
A. S. Loskutov ◽  
...  
Keyword(s):  
Nonmetallic Inclusions ◽  
Mechanism Of Formation
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