Non-metallic inclusions in electroslag remelting: a review

2022 ◽  
Author(s):  
Cheng-bin Shi ◽  
Shi-jun Wang ◽  
Jing Li ◽  
Jung-wook Cho
Keyword(s):  
Electroslag Remelting ◽  
Metallic Inclusions

Numerical study on the removal and distribution of non-metallic inclusions in electroslag remelting process

2019 ◽  
Vol 135 ◽  
pp. 1300-1311 ◽  
Author(s):  
Xuechi Huang ◽  
Baokuan Li ◽  
Zhongqiu Liu ◽  
Xiao Yang ◽  
Fumitaka Tsukihashi
Keyword(s):  
Numerical Study ◽  
Electroslag Remelting ◽  
Metallic Inclusions

scholarly journals Formation and Evolution of Non-Metallic Inclusions in Calcium Treatment H13 Steel during Electroslag Remelting Process

2019 ◽  
Vol 59 (5) ◽  
pp. 828-838 ◽  
Author(s):  
Hao Wang ◽  
Jing Li ◽  
Chengbin Shi ◽  
Yongfeng Qi ◽  
Yuxiang Dai
Keyword(s):  
Electroslag Remelting ◽  
Calcium Treatment ◽  
H13 Steel ◽  
Metallic Inclusions ◽  
Formation And Evolution

scholarly journals Effect of electroslag remelting on the non-metallic inclusions in H11 tool steel

2018 ◽  
Vol 54 (1) ◽  
pp. 51-57 ◽  
Author(s):  
J. Burja ◽  
F. Tehovnik ◽  
M. Godec ◽  
J. Medved ◽  
B. Podgornik ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Tool Steel ◽  
Single Phase ◽  
Thermodynamic Assessment ◽  
Electroslag Remelting ◽  
Metallic Inclusion ◽  
Inclusion Content ◽  
Metallic Inclusions

We have studied the effect of electroslag remelting on the content and composition of non-metallic inclusions. It was found that a decrease in the non-metallic inclusion content occurred during the electroslag remelting. A change in the chemical composition of the non-metallic inclusions was observed, while the aluminum and calcium contents were increased. The complexity of the inclusions also increased, as there were fewer single-phase inclusions after the electroslag remelting process. Based on the results and a thermodynamic assessment of the formation of the non-metallic inclusions, a mechanism for inclusion behavior during electroslag remelting has been proposed.

scholarly journals The effect of electroslag remelting on the cleanliness of CrNiMoWMnV ultrahigh-strength steels

2019 ◽  
Vol 55 (3) ◽  
pp. 381-395 ◽  
Author(s):  
M. Ali ◽  
D. Porter ◽  
J. Kömi ◽  
E.P. Heikkinen ◽  
M. Eissa ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Electroslag Remelting ◽  
Chemical Compositions ◽  
Free Energies ◽  
Scanning Confocal Microscopy ◽  
Ultrahigh Strength ◽  
Metallic Inclusions ◽  
Ultrahigh Strength Steels ◽  
Hsc Chemistry

The cleanliness of ultrahigh-strength steels (UHSSs) without and with electroslag remelting (ESR) using a slag with the composition of 70% CaF2, 15% Al2O3, and 15% CaO was studied. Three experimental heats of UHSSs with different chemical compositions were designed, melted in an induction furnace, and refined using ESR. Cast ingots were forged at temperatures between 1100 and 950?C, air cooled, and their non-metallic inclusions (NMIs) were characterized using field emission scanning electron microscopy and laser scanning confocal microscopy. Thermodynamic calculations for the expected NMIs formed in the investigated steels with and without ESR were performed using FactSage 7.2 software while HSC Chemistry version 9.6.1 was used to calculate the standard Gibbs free energies (?G?). As a result of ESR the total impurity levels (TIL% = O% + N% + S%) and NMI contents decreased by as much as 46 % and 62 %, respectively. The NMIs were classified into four major classes: oxides, sulphides, nitrides, and complex multiphase inclusions. ESR brings about large changes in the area percentages, number densities, maximum equivalent circle diameters, and the chemical composition of the various NMIs. Most MnS inclusions were removed although some were re-precipitated on oxide or nitride inclusions leading to multiphase inclusions with an oxide or nitride core surrounded by sulphide, e.g. (MnS.Al2O3) and (MnS. TiN). Also, some sulphides are modified by Ca forming (CaMn)S and CaS.Al2O3. Some nitrides like TiN and (TiV)N are nucleated and precipitated during the solidification phase. Al2O3 inclusions were formed as a result of the addition of Al as a deoxidant to the ESR slag to prevent penetration of oxygen to the molten steel.

scholarly journals Numerical Simulation on Motion Behavior of Inclusions in the Lab-Scale Electroslag Remelting Process with a Vibrating Electrode

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1784
Author(s):  
Fang Wang ◽  
Boyang Sun ◽  
Zhongqiu Liu ◽  
Baokuan Li ◽  
Shuo Huang ◽  
...  
Keyword(s):  
Vibration Frequency ◽  
Slag Layer ◽  
Continuous Phase ◽  
Filling Ratio ◽  
Electroslag Remelting ◽  
Discrete Phase Model ◽  
High Quality ◽  
Removal Ratio ◽  
Metallic Inclusions ◽  
Motion Behavior

In order to meet the requirement of high-quality ingots, the vibrating electrode technique in the electroslag remelting (ESR) process has been proposed. Non-metallic inclusions in ingots may cause serious defects and deteriorate mechanical properties of final products. Moreover, the dimension, number and distribution of non-metallic inclusions should be strictly controlled during the ESR process in order to produce high-quality ingots. A transient 2-D coupled model is established to analyze the motion behavior of inclusions in the lab-scale ESR process with a vibrating electrode, especially under the influence of the vibration frequency, current, slag layer thickness, and filling ratio, as well as type and diameter of inclusions. Simulation model of inclusions motion behavior is established based on the Euler-Lagrange approach. The continuous phase including metal and slag, is calculated based on the volume of fluid (VOF) method, and the trajectory of inclusions is tracked with the discrete phase model (DPM). The vibrating electrode is simulated by the user-defined function and dynamic mesh. The results show that when the electrode vibration frequency is 0.25 Hz or 1 Hz, the inclusions will gather on one side of the slag layer. When it increases from 0.25 Hz to 1 Hz, the removal ratio of 10 μm and 50 μm inclusions increases by 5% and 4.1%, respectively. When the current increases from 1200 A to 1800 A, the flow following property of inclusions in the slag layer becomes worse. The removal ratio of inclusions reaches the maximum value of 92% with the current of 1500 A. The thickness of slag layer mainly affects the position of inclusions entering the liquid-metal pool. As the slag layer thickens, the inclusions removal ratio increases gradually from 82.73% to 85.91%. As the filling ratio increases, the flow following property of inclusions in the slag layer is enhanced. The removal ratio of 10 μm inclusions increases from 94.82% to 97%. However, for inclusions with a diameter of 50 μm, the maximum removal ratio is 96.04% with a filling ratio of 0.46. The distribution of 50 μm inclusions is significantly different, while the distribution of 10μm inclusions is almost similar. Because of the influence of a vibrating electrode, 10 μm Al2O3 and MnO have a similar removal ratios of 81.33% and 82.81%, respectively.

THE EFFECT OF NON-METALLIC INCLUSIONS AND FILMS ON THE CATHODE ON SOME PROCESSES DURING VACUUM DISCHARGES

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-411-C7-412
Author(s):  
D. I. Proskourovsky ◽  
V. F. Puchkarev
Keyword(s):  
Metallic Inclusions

RESEARCH ON THE NON-METALLIC INCLUSIONS OF KILLED STEEL (I)

1956 ◽  
Vol 42 (10) ◽  
pp. 962-968
Author(s):  
Yosaku Koike ◽  
Sahei Noda
Keyword(s):  
Metallic Inclusions

Determination of non-metallic inclusions in metal alloys by spark atomic emission spectrometry (review)

2018 ◽  
Vol 84 (12) ◽  
pp. 5-19
Author(s):  
D. N. Bock ◽  
V. A. Labusov
Keyword(s):  
Spectral Line ◽  
Internal Standard ◽  
Detection Limits ◽  
Radiation Detectors ◽  
Metal Alloys ◽  
Emission Spectrometry ◽  
Direct Production ◽  
Metallic Inclusions ◽  
Dissolved Form

A review of publications regarding detection of non-metallic inclusions in metal alloys using optical emission spectrometry with single-spark spectrum registration is presented. The main advantage of the method - an extremely short time of measurement (~1 min) – makes it useful for the purposes of direct production control. A spark-induced impact on a non-metallic inclusion results in a sharp increase (flashes) in the intensities of spectral lines of the elements that comprise the inclusion because their content in the metal matrix is usually rather small. The intensity distribution of the spectral line of the element obtained from several thousand of single-spark spectra consists of two parts: i) the Gaussian function corresponding to the content of the element in a dissolved form, and ii) an asymmetric additive in the region of high intensity values ??attributed to inclusions. Their quantitative determination is based on the assumption that the intensity of the spectral line in the single-spark spectrum is proportional to the content of the element in the matter ablated by the spark. Thus, according to the calibration dependence constructed using samples with a certified total element content, it is possible not only to determine the proportions of the dissolved and undissolved element, but also the dimensions of the individual inclusions. However, determination of the sizes is limited to a range of 1 – 20 µm. Moreover, only Al-containing inclusions can be determined quantitatively nowadays. Difficulties occur both with elements hardly dissolved in steels (O, Ca, Mg, S), and with the elements which exhibit rather high content in the dissolved form (Si, Mn). It is also still impossible to determine carbides and nitrides in steels using C and N lines. The use of time-resolved spectrometry can reduce the detection limits for inclusions containing Si and, possibly, Mn. The use of the internal standard in determination of the inclusions can also lower the detection limits, but may distort the results. Substitution of photomultipliers by solid-state linear radiation detectors provided development of more reliable internal standard, based on the background value in the vicinity of the spectral line. Verification of the results is difficult in the lack of standard samples of composition of the inclusions. Future studies can expand the range of inclusions to be determined by this method.

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