Effect of CeO2 addition in the slag on inclusions of FGH96 superalloy during electroslag remelting

The FGH96 superalloy was electroslag remelted by utilizing CeO2 containing slag. CeO2/Al2O3 ratio and atmosphere are found to be the main factors that control the oxide inclusion contents during electroslag remelting (ESR). The reaction between CeO2 in the molten slag and Al in the molten alloy leads to the increased dissolved Ce in the molten alloy, which is effective to remove oxide inclusions. Dissolved Ce reacts with MgO in the inclusions, leading to the transformation of Al2O3–MgO inclusion in the electrode to Al2O3–MgO–Ce2O3 and Al2O3–Ce2O3 inclusions in the ESR ingot. In case of low CeO2/Al2O3 ratio of 0.263, oxygen content decreases to as low as 8 ppm after ESR under vacuum, and the number density of oxide inclusion decreased by an order of magnitude in comparison to the electrode. In case of high CeO2/Al2O3 ratio of 5.0, oxygen content decreases further to 6 ppm no matter what the condition is.

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Effect of SiO2 containing slag for electroslag remelting on inclusion modification of 42CrMo steel

Metallurgical Research & Technology ◽

10.1051/metal/2019063 ◽

2019 ◽

Vol 116 (6) ◽

pp. 627 ◽

Cited By ~ 1

Author(s):

Yu Liu ◽

Zhao Zhang ◽

Guangqiang Li ◽

Yang Wu ◽

Xijie Wang ◽

...

Keyword(s):

Slag Composition ◽

Molten Slag ◽

Oxide Inclusion ◽

Electroslag Remelting ◽

Slag Viscosity ◽

Oxide Inclusions ◽

Al Content ◽

42Crmo Steel ◽

Increasing Trend ◽

Inclusion Modification

Five heats were carried out to study the effects of SiO2 containing slag for electroslag remelting (ESR) on inclusion characteristics of 42CrMo steel. Fluoride vaporization at elevated temperature from slags was also explored by thermogravimetric analysis. The results show that fluoride vaporization is dominated by slag viscosity and component activities in the melt. Slag composition has an important effect on the composition of the oxide inclusion. For 70 wt% CaF2–30 wt% Al2O3 slag, the compositions of oxide inclusions in remelted steel show no obvious differences compared with the virgin steel. Whereas, SiO2 content in oxide inclusions of steel processed by slag bearing SiO2 show an increasing trend with increase of SiO2 content in 50 wt% CaF2–CaO–SiO2 slag, and the MgO · Al2O3 inclusions are modified to (Al,Ca,Mg,Si)O inclusions with low melting temperature. Al2O3 contents in oxide inclusions are also closely related to the Al2O3 concentration in the molten slag, which increase with the addition of Al2O3 in slag bearing SiO2. In testing various slags, the incorporation of slag T2 with 50 wt% CaF2–30 wt% CaO–20 wt% SiO2 shows the highest cleanliness in remelted steel. This implies that slag T2 can be a promising slag for ESR process of alloy steel requiring Al content refinement due to less fluoride vaporization from slag and better inclusions modification.

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Effect of Dissolved Oxygen Content on Gelling Strength of Chromium Gel in Block Hai 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1008-1009.243 ◽

2014 ◽

Vol 1008-1009 ◽

pp. 243-246

Author(s):

Peng Fei Yuan ◽

Guang Sheng Cao ◽

Xiao Ma ◽

Xiao Ping Wang ◽

Xin Tian

Keyword(s):

Dissolved Oxygen ◽

Oxygen Content ◽

Good Effect ◽

Factors Affecting ◽

Profile Control ◽

Liaohe Oilfield ◽

Weak Gel ◽

Main Factors ◽

Implementation Effect ◽

Gelling Time

Jinma company of Liaohe oilfield has carried out weak gel flooding in-depth in block Hai1 and achieved good effect. But in the process of profile and flooding, problems of gelation fluctuating and gelling rate declining seriously affected the implementation effect of the profile control and flooding project. It is researched that one of main factors affecting gelling effect of profile and flooding system is the dissolved oxygen. Aiming at this problem, this paper studies critical value affecting gelling in combination with the actual situation of polymer displacement in block Hai 1. The experimental results show that, content of dissolved oxygen affects both gelling strength and gelling time of weak gel in the way that when dissolved oxygen content is between 0mg/L and 3mg/L, low gelling strength and long gelling time are obtained, while in the range of 4mg/L-10mg/L, gelling effect is good. Two critical values are respective 1.5mg/L and 7mg/L.

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Hot and cold running water: understanding evolved star winds

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317010602 ◽

2017 ◽

Vol 13 (S336) ◽

pp. 347-350

Author(s):

A. M. S. Richards ◽

M. D. Gray ◽

A. Baudry ◽

E. M. L. Humphreys ◽

S. Etoka ◽

...

Keyword(s):

Mass Loss ◽

Circumstellar Envelope ◽

Number Density ◽

Running Water ◽

Physical Conditions ◽

Evolved Stars ◽

Order Of Magnitude ◽

Homogeneous Regions ◽

Maser Sources

AbstractOutstanding problems concerning mass-loss from evolved stars include initial wind acceleration and what determines the clumping scale. Reconstructing physical conditions from maser data has been highly uncertain due to the exponential amplification. ALMA and e-MERLIN now provide image cubes for five H2O maser transitions around VY CMa, at spatial resolutions comparable to the size of individual clouds or better, covering excitation states from 204 to 2360 K. We use the model of Gray et al. 2016, to constrain variations of number density and temperature on scales of a few au, an order of magnitude finer than is possible with thermal lines, comparable to individual cloud sizes or locally almost homogeneous regions. We compare results with the models of Decin et al. 2006 and Matsuura et al. 2014 for the circumstellar envelope of VY CMa; in later work this will be extended to other maser sources.

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Investigation of Oxide Inclusions and Primary Carbonitrides in Inconel 718 Superalloy Refined through Electroslag Remelting Process

Metallurgical and Materials Transactions B ◽

10.1007/s11663-012-9723-6 ◽

2012 ◽

Vol 43 (6) ◽

pp. 1596-1607 ◽

Cited By ~ 34

Author(s):

Xi-Chun Chen ◽

Cheng-Bin Shi ◽

Han-Jie Guo ◽

Fei Wang ◽

Hao Ren ◽

...

Keyword(s):

Inconel 718 ◽

Electroslag Remelting ◽

Oxide Inclusions ◽

Inconel 718 Superalloy

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Inclusion Characteristics in 95CrMo Steels with Different Calcium and Sulfur Contents

Materials ◽

10.3390/ma13030619 ◽

2020 ◽

Vol 13 (3) ◽

pp. 619 ◽

Cited By ~ 1

Author(s):

Xiang Li ◽

Xiao Long ◽

Linzhu Wang ◽

Shouhao Tong ◽

Xiutao Wang ◽

...

Keyword(s):

Outer Layer ◽

Three Dimensional ◽

Average Diameter ◽

Inclusion Size ◽

Number Density ◽

Cooling Process ◽

Oxide Inclusions ◽

Industrial Experiments ◽

Size Number

In order to study the effect of Ca and sulfur contents on the characteristics of inclusions, industrial experiments using 95CrMo steel were conducted. SEM-EDS detections and stereological analysis were used to probe the characteristics of inclusions, including their compositions, morphologies, size, number density, and distribution. The results indicate that there were mainly three types of inclusions in 95CrMo steel billets with 6–18 ppm Ca and 30–100 ppm S: inclusions with single-phased morphology mainly composed of oxides; isolated MnS/CaS-only inclusions; inclusions with multi-phased morphology. The three-dimensional inclusion size distribution suggests that there were more Type-1 inclusions with a small size in low S containing steels. The average diameter of all types of inclusions increased with increasing Ca or S content in 95CrMo steel, indicating that the formation of MnS and CaS coarsened their size. The density distribution of inclusions indicates that the more inclusions there are, the more easily they aggregate and collide. Moreover, it is presumably concluded that the formation of sulfide in the outer layer of oxide inclusions weaken the attraction between oxide inclusions. The equilibrated transformation and formation of inclusions during the cooling process of 95CrMo steel was discussed based on thermodynamic calculation. The equilibrated transformation trajectory of inclusions in 95CrMo steel during the cooling process was Ca2SiO4 + MgO → Ca3MgSi2O8 → Spinel + CaS, which was corresponding to the detected results. The precipitation regular of sulfide was obtained. The formation mechanism for three types of inclusions was discussed.

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Evolution of TiN and Oxide Inclusions in Ti-containing Fe-25Ni-15Cr Alloy during Electroslag Remelting

ISIJ International ◽

10.2355/isijinternational.isijint-2019-603 ◽

2020 ◽

Vol 60 (8) ◽

pp. 1577-1585 ◽

Cited By ~ 1

Author(s):

Dingli Zheng ◽

Jing Li ◽

Chengbin Shi ◽

Jie Zhang ◽

Ruming Geng

Keyword(s):

Electroslag Remelting ◽

Oxide Inclusions

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QUANTUM REFLECTION OF MASSLESS NEUTRINOS FROM A TORSION-INDUCED POTENTIAL

International Journal of Modern Physics A ◽

10.1142/s0217751x00001130 ◽

2000 ◽

Vol 15 (26) ◽

pp. 4099-4106

Author(s):

M. ALIMOHAMMADI ◽

A. SHARIATI

Keyword(s):

Gravitational Interaction ◽

Effective Field ◽

Neutrino Beam ◽

Theory Approach ◽

Number Density ◽

Quantum Reflection ◽

Reflection Amplitude ◽

Order Of Magnitude ◽

Massless Neutrino ◽

Specific Fraction

In the context of the Einstein–Cartan–Dirac model, where the torsion of the space–time couples to the axial currents of the fermions, we study the effects of this quantum-gravitational interaction on a massless neutrino beam crossing through a medium with a high number density of fermions at rest. We calculate the reflection amplitude and show that a specific fraction of the incident neutrinos reflects from this potential if the polarization of the medium is different from zero. We also discuss the order of magnitude of the fermionic number density in which this phenomenon is observable, in other theoretical contexts, for example, the strong gravity regime and the effective field theory approach.

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The Effect of Hot Deformation on Dispersoid Evolution in a Model 3xxx Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.794-796.697 ◽

2014 ◽

Vol 794-796 ◽

pp. 697-703 ◽

Cited By ~ 4

Author(s):

Joseph D. Robson ◽

Thomas Hill ◽

Nicolas Kamp

Keyword(s):

Hot Deformation ◽

High Strain ◽

Volume Fraction ◽

Strain Rates ◽

Number Density ◽

Key Factor ◽

Order Of Magnitude ◽

Hot Torsion ◽

3Xxx Alloy ◽

Magnitude Increase

The influence of hot deformation on the evolution of size, shape, and fraction of dispersoids has been studied in a simple 3xxx aluminium alloy by means of hot torsion testing. It has been shown that at high strain rates, deformation leads to spheroidization of the dispersoids, an increase in number density, and an increase in volume fraction. The increase in number density and volume fraction are associated with precipitation of new particles. The enhancement of manganese diffusion is a key factor in promoting rapid dispersoid evolution during deformation. A model has been developed to estimate the effect of deformation induced vacancies and dislocations on diffusion. This predicts that an order of magnitude increase in diffusion coefficient between may occur under typical hot deformation conditions, consistent with the rapid microstructural changes measured experimentally.

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