scholarly journals An Investigation of Non-Metallic Inclusions in Different Ferroalloys using Electrolytic Extraction

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 687 ◽  
Author(s):  
Yong Wang ◽  
Andrey Karasev ◽  
Pär G. Jönsson
Keyword(s):  
Three Dimensional ◽  
Size Distributions ◽  
Steelmaking Process ◽  
Particle Size Distributions ◽  
Electrolytic Extraction ◽  
Cast Steels ◽  
Metallic Inclusions ◽  
Pure Sio2 ◽  
Pure Al2o3

Ferroalloys are integral constituents of the steelmaking process, since non-metallic inclusions (NMIs) from ferroalloys significantly influence the transformation of inclusions present in liquid steel or they are directly involved in casted steel. In this study, the characteristics of inclusions (such as the number, morphology, size, and composition) in different industrial ferroalloys (FeV, FeMo, FeB, and FeCr) were investigated using the electrolytic extraction (EE) technique. After extraction from the ferroalloy samples and filtration of the solution, the inclusions were investigated on a film filter. The three-dimensional (3D) investigations were conducted using a scanning electron microscopy in combination with energy dispersive spectroscopy (SEM-EDS). The characteristics of inclusions observed in the ferroalloys were compared with previous results and discussed with respect to their possible behaviors in the melt and their effects on the quality of the cast steels. The particle size distributions and floatation distances were plotted for the main inclusion types. The results showed that the most harmful inclusions in the ferroalloys investigated are the following: pure Al2O3 and high Al2O3-containing inclusions in FeV alloys; pure SiO2 and high SiO2-containing inclusions in FeMo alloys; Al2O3 and SiO2-containing inclusions in FeB alloys; and MnO-Cr2O3, Al2O3, and Cr2O3-based inclusions in FeCr alloys.

scholarly journals Characterization of non-metallic inclusions in corrosion -resistance nickel - based EP718 and 718 alloys by using electrolytic extraction method

2019 ◽  
Vol 121 ◽  
pp. 04004 ◽  
Author(s):  
Andrey Karasev ◽  
Ekaterina Alekseeva ◽  
Aleksey Lukianov ◽  
Pär G. Jönsson
Keyword(s):  
Corrosion Resistance ◽  
Extraction Method ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Steel Production ◽  
Immersion Test ◽  
Corrosion Properties ◽  
Electrolytic Extraction ◽  
Electrochemical Tests ◽  
Metallic Inclusions

It is known that non-metallic inclusions (NMI) that are formed during steel production and heat treatment can significantly affect the properties of final steel products. Therefore, it is very important to be able to determine the content of harmful NMI in steels. Nickel-based alloys are widely used in the oil and gas recovery industry, due to a good combination of strength and corrosion properties. Earlier studies have shown that the corrosion properties in immersion test and electrochemical tests for Ni-based EP718 alloys are slightly lower than that for 718 alloys. The focus in this study was the influence of different NMI on the corrosion resistance of these alloys. The characteristics of inclusions (such as size, morphology, and chemical composition) were analysed by using the electrolytic extraction method followed by three-dimensional investigations using SEM in combination with EDS. It was found that some non-metallic inclusions in EP718 alloys significantly reduce its corrosion resistance. It was also shown that a primary dissolution of the metal matrix occurs around certain inclusions during electrolytic extraction. Based on obtained results, the corrosion active non-metallic inclusions can be determined in these Nickel-base alloys and some recommendations for optimization of their production technology can be formulated.

Stereological estimation of particle size distributions

1995 ◽  
Vol 27 (02) ◽  
pp. 350-366 ◽  
Author(s):  
Shigeru Mase
Keyword(s):  
Empirical Distribution ◽  
Three Dimensional ◽  
Estimation Procedure ◽  
Distribution Functions ◽  
Size Distributions ◽  
Thick Section ◽  
Particle Size Distributions ◽  
Sectional Plane ◽  
Simulation Results ◽  
Empirical Distribution Functions

The corpuscle problem of Wicksell is discussed. We give a numerical quadrature of Gauss–Chebyshev type for Wicksell's integral equation which combines a size distribution of discs on a sectional plane with that of spheres. We also give an estimation procedure of three-dimensional size distributions based on this quadrature and examine its theoretical properties. In practice, we need a smoothing technique for empirical distribution functions before applying this estimator. Simulation results are given. Our idea also is applied to the thick section case and an analysis of microscopic data is given.

scholarly journals Cloud particle size distributions measured with an airborne digital in-line holographic instrument

2009 ◽  
Vol 2 (1) ◽  
pp. 259-271 ◽  
Author(s):  
J. P. Fugal ◽  
R. A. Shaw
Keyword(s):  
Particle Size ◽  
Three Dimensional ◽  
Sample Volume ◽  
Equivalent Diameter ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Holographic Method ◽  
Cloud Particle ◽  
Data Set ◽  
Two Dimensional Image

Abstract. Holographic data from the prototype airborne digital holographic instrument HOLODEC (Holographic Detector for Clouds), taken during test flights are digitally reconstructed to obtain the size (equivalent diameters in the range 23 to 1000 μm), three-dimensional position, and two-dimensional image of ice particles and then ice particle size distributions and number densities are calculated using an automated algorithm with minimal user intervention. The holographic method offers the advantages of a well-defined sample volume size that is not dependent on particle size or airspeed, and offers a unique method of detecting shattered particles. The holographic method also allows the volume sample rate to be increased beyond that of the prototype HOLODEC instrument, limited solely by camera technology. HOLODEC size distributions taken in mixed-phase regions of cloud compare well to size distributions from a PMS FSSP probe also onboard the aircraft during the test flights. A conservative algorithm for detecting shattered particles utilizing their depth-position along the optical axis eliminates the obvious ice particle shattering events from the data set. In this particular case, the size distributions of non-shattered particles are reduced by approximately a factor of two for particles 15 to 70 μm in equivalent diameter, compared to size distributions of all particles.

Stereological estimation of particle size distributions

1995 ◽  
Vol 27 (2) ◽  
pp. 350-366 ◽  
Author(s):  
Shigeru Mase
Keyword(s):  
Empirical Distribution ◽  
Three Dimensional ◽  
Estimation Procedure ◽  
Distribution Functions ◽  
Size Distributions ◽  
Thick Section ◽  
Particle Size Distributions ◽  
Sectional Plane ◽  
Simulation Results ◽  
Empirical Distribution Functions

The corpuscle problem of Wicksell is discussed. We give a numerical quadrature of Gauss–Chebyshev type for Wicksell's integral equation which combines a size distribution of discs on a sectional plane with that of spheres. We also give an estimation procedure of three-dimensional size distributions based on this quadrature and examine its theoretical properties. In practice, we need a smoothing technique for empirical distribution functions before applying this estimator. Simulation results are given. Our idea also is applied to the thick section case and an analysis of microscopic data is given.

scholarly journals Cloud particle size distributions measured with an airborne digital in-line holographic instrument

2009 ◽  
Vol 2 (2) ◽  
pp. 659-688 ◽  
Author(s):  
J. P. Fugal ◽  
R. A. Shaw
Keyword(s):  
Particle Size ◽  
Three Dimensional ◽  
Sample Volume ◽  
Equivalent Diameter ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Holographic Method ◽  
Cloud Particle ◽  
Data Set ◽  
Unique Method

Abstract. Holographic data from the prototype airborne digital holographic instrument HOLODEC (Holographic Detector for Clouds), taken during test flights are digitally reconstructed to obtain the size (equivalent diameters in the range 23 to 1000 μm), three-dimensional position, and two-dimensional profile of ice particles and then ice particle size distributions and number densities are calculated using an automated algorithm with minimal user intervention. The holographic method offers the advantages of a well-defined sample volume size that is not dependent on particle size or airspeed, and offers a unique method of detecting shattered particles. The holographic method also allows the volume sample rate to be increased beyond that of the prototype HOLODEC instrument, limited solely by camera technology. HOLODEC size distributions taken in mixed-phase regions of cloud compare well to size distributions from a PMS FSSP probe also onboard the aircraft during the test flights. A conservative algorithm for detecting shattered particles utilizing the particles depth-position along the optical axis eliminates the obvious ice particle shattering events from the data set. In this particular case, the size distributions of non-shattered particles are reduced by approximately a factor of two for particles 15 to 70 μm in equivalent diameter, compared to size distributions of all particles.

scholarly journals Vertical Structure and Microphysical Characteristics of Frontal Systems Passing over a Three-Dimensional Coastal Mountain Range

2019 ◽  
Vol 76 (6) ◽  
pp. 1521-1546 ◽  
Author(s):  
Joseph P. Zagrodnik ◽  
Lynn A. McMurdie ◽  
Robert A. Houze ◽  
Simone Tanelli
Keyword(s):  
Particle Size ◽  
Precipitation Amount ◽  
Three Dimensional ◽  
Windward Side ◽  
Mountain Range ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Surface Precipitation ◽  
Coastal Mountain ◽  
Midlatitude Cyclones

Abstract As midlatitude cyclones pass over a coastal mountain range, the processes producing their clouds and precipitation are modified, leading to considerable spatial variability in precipitation amount and composition. Statistical diagrams of airborne precipitation radar transects, surface precipitation measurements, and particle size distributions are examined from nine cases observed during the Olympic Mountains Experiment (OLYMPEX). Although the pattern of windward enhancement and leeside diminishment of precipitation was omnipresent, the degree of modulation was largely controlled by the synoptic environment associated with the prefrontal, warm, and postfrontal sectors of midlatitude cyclones. Prefrontal sectors contained homogeneous stratiform precipitation with a slightly enhanced ice layer on the windward slopes and rapid diminishment to a near-complete rain shadow in the lee. Warm sectors contained deep, intense enhancement over both the windward slopes and high terrain and less prominent rain shadows owing to downstream spillover of ice particles generated over terrain. Surface particle size distributions in the warm sector contained a broad spectrum of sizes and concentrations of raindrops on the lower windward side where high precipitation rates were achieved from varying degrees of both liquid and ice precipitation-generating processes. Spillover precipitation was rather homogeneous in nature and lacked the undulations in particle size and concentration that occurred at the windward sites. Postfrontal precipitation transitioned from isolated convective cells over ocean to a shallow, mixed convective–stratiform composition with broader coverage and greater precipitation rates over the sloping terrain.

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