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 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.

Composition-size distribution diagrams for alloy catalysts

1995 ◽  
Vol 53 ◽  
pp. 404-405
Author(s):  
C. E. Lyman ◽  
R. E. Lakis ◽  
H. G. Stenger
Keyword(s):  
Size Distribution ◽  
Average Pore Size ◽  
Analytical Electron Microscopy ◽  
Reduction Reaction ◽  
Distribution Diagram ◽  
Average Pore ◽  
Alloy Particles ◽  
Alumina Particles ◽  
Analytical Electron ◽  
Alloy Catalysts

Catalyst microstructure and catalytic properties can be directly correlated using a composition-size distribution diagram that maps the phases of small alloy particles by composition and size. The application of this diagram given here concerns Pt-Rh/alumina catalysts for reduction of NO in hydrogen at low temperatures. The composition-size diagram provides an understanding of why some alloy catalysts perform worse than pure Pt in the NO reduction reaction, while other preparations exhibit the several times the activity of pure Pt. The composition-size diagram can be used to "fingerprint" active and less active alloy catalysts. Analytical electron microscopy (AEM) has been used to determine the Pt-Rh particle composition-size distribution.Catalysts were prepared by aqueous impregnation of platinum chloride into gamma-alumina particles with a 4 nm average pore size. After impregnation and air drying, the catalyst was calcined in air at 500°C for 3 hr. Subsequently, rhodium was impregnated from its chloride into the same support material, and the preparation was air-dried.

scholarly journals Effect of grater position on the size of grated sago (Metroxylon spp.)

Food Research ◽  
2018 ◽  
Vol 2 (6) ◽  
pp. 572-577
Author(s):  
Wan Mohd Fariz W.A. ◽  
Rosnah S. ◽  
Azman H. ◽  
Mohd Shahrir A. ◽  
Saiful Azwan A. ◽  
...  
Keyword(s):  
Size Distribution ◽  
Outer Layer ◽  
Fiber Orientation ◽  
Vertical Axis ◽  
Total Weight ◽  
Sago Starch ◽  
Sago Palm

The natural arrangement of sago palm’s fiber orientation is parallel to the vertical axis of the trunk. Extraction of the sago starch requires breaking of the trunk into fine sizes. The sago size is affected by the grater position which affects the of starch recovery. This study was conducted to evaluate grating efficiency through sago size produced at the different direction of grating (0° and 90° to roller teeth rotation). Sago palm trunks without outer layer were cut into square blocks of 100 mm3 . Each trunk block was placed on roller grater platform at a different position where the cutting spike was parallel to the vertical axis of sago trunk fiber orientation (grating at 0° direction) and perpendicular (grating at 90° direction). 100 g of dry grated sago was sifted to determine the size distribution with different sieve sizes i.e. 2.80 mm, 2.00 mm, 1.00 mm, 0.85 mm and 0.425 mm. A total weight of 1 kg of grated sago was mixed with water and squeezed to be extracted. The starch recovery produced by the grating process at 0° directionswas 10.30% higher than 900 directions. The present study showed that the direction of grating at 0° was able to produce finer grated sago with maximum starch recovery.

The extinction time of a general birth and death process with catastrophes

1986 ◽  
Vol 23 (04) ◽  
pp. 851-858 ◽  
Author(s):  
P. J. Brockwell
Keyword(s):  
Laplace Transform ◽  
Size Distribution ◽  
Sufficient Conditions ◽  
Necessary And Sufficient Conditions ◽  
Death Process ◽  
Extinction Time ◽  
Birth And Death Process ◽  
Different Types ◽  
The Laplace Transform ◽  
Necessary And Sufficient

The Laplace transform of the extinction time is determined for a general birth and death process with arbitrary catastrophe rate and catastrophe size distribution. It is assumed only that the birth rates satisfyλ0= 0,λj> 0 for eachj> 0, and. Necessary and sufficient conditions for certain extinction of the population are derived. The results are applied to the linear birth and death process (λj=jλ, µj=jμ) with catastrophes of several different types.

Macrostructure and microphysics of Saturn's E-ring

1984 ◽  
Vol 75 ◽  
pp. 607-613 ◽  
Author(s):  
Kevin D. Pang ◽  
Charles C. Voge ◽  
Jack W. Rhoads
Keyword(s):  
Size Distribution ◽  
Spherical Shape ◽  
Mie Scattering ◽  
Narrow Size Distribution ◽  
Electrostatic Levitation ◽  
Volcanic Origin ◽  
Micron Diameter

Abstract.All observed optical and infrared properties of Saturn's E-ring can be explained in terms of Mie scattering by a narrow size distribution of ice spheres of 2 - 2.5 micron diameter. The spherical shape of the ring particles and their narrow size distribution imply a molten (possibly volcanic) origin on Enceladus. The E-ring consists of many layers, possibly stratified by electrostatic levitation.

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