Evolution of nonmetallic inclusions in 80-t 9CrMoCoB large-scale ingots during electroslag remelting process

In combination with theoretical calculations,experiments were conducted to investigate the evolution behavior of nonmetallic inclusions(NMIs)during the manufacture of large-scale heat-resistant steel ingots using 9CrMoCoB heat-resistant steel and CaF_(2)–CaO–Al_(2)O_(3)–SiO_(2)–B_(2)O_(3)electroslag remelting(ESR)-type slag in an 80-t industrial ESR furnace.The main types of NMI in the consumable electrode comprised pure alumina,a multiphase oxide consisting of an Al_(2)O_(3)core and liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO shell,and M_(23)C_(6)carbides with an MnS core.The Al_(2)O_(3)and MnS inclusions had higher precipitation temperatures than the M_(23)C_(6)-type carbide under equilibrium and nonequilibrium solidification processes.Therefore,inclusions can act as nucleation sites for carbide layer precipitation.The ESR process completely removed the liquid CaO–Al_(2)O_(3)–SiO_(2)–MnO oxide and MnS inclusion with a carbide shell,and only the Al_(2)O_(3)inclusions and Al_(2)O_(3)core with a carbide shell occupied the remelted ingot.The M_(23)C_(6)-type carbides in steel were determined as Cr_(23)C_(6)based on the analysis of transmission electron microscopy results.The substitution of Cr with W,Fe,or/and Mo in the Cr_(23)C_(6)lattice caused slight changes in the lattice parameter of the Cr_(23)C_(6)carbide.Therefore,Cr_(21.34)Fe_(1.66)C_(6),(Cr_(19)W_(4)C_(6),Cr_(18.4)Mo_(4.6)C_(6),and Cr_(16)Fe_(5)Mo_(2)C_(6)can match the fraction pattern of Cr_(23)C_(6)carbide.The Al_(2)O_(3)inclusions in the remelted ingot formed due to the reduction of CaO,SiO_(2),and MnO components in the liquid inclusion.The increased Al content in liquid steel or the higher supersaturation degree of Al_(2)O_(3)precipitation in the remelted ingot than that in the electrode can be attributed to the evaporation of CaF_(2)and the increase in CaO content in the ESR-type slag.

Clinical features,radiological imaging,and treatment strategies of nonmetallic intraorbital foreign bodies:a retrospective analysis

AIM:To provide comprehensive data on nonmetallic intraorbital foreign bodies(IOFBs)by summarizing and analyzing material types,clinical manifestations,imaging features,and treatment strategies.METHODS:Totally 28 nonmetallic IOFB cases treated at Shengjing Hospital of China Medical University from 2012 to 2020 were retrospectively reviewed.The types of foreign bodies,clinical features,imaging manifestations,and treatment outcomes were analyzed.RESULTS:Among all cases,67.8%(19/28)of the foreign bodies were organic.The top three entrances were the upper eyelid skin(7/28),lower fornix conjunctiva(6/28),and lower eyelid skin(4/28).In most cases(11/28,39.3%),foreign bodies remained in the medial orbits.The major clinical manifestations included eyelid redness and swelling(20/28,71.4%),conjunctival congestion and edema(17/28,60.7%),and ophthalmoptosis(15/28,53.6%).Infection was the main complication,which occurred in 57.1%(16/28)of all cases.Computerized tomography(CT)values differed for different foreign bodies and varied in the different periods after injury.The plant-and grease-derived foreign bodies and the surrounding pus cysts showed different signals on magnetic resonance imaging(MRI).The prognosis varied with different foreign body types,surgery timing,and intraoperative management.CONCLUSION:The majority of nonmetallic IOFBs are organic and often remain in the superior,medial,and inferior areas of the orbit.Clinical manifestations vary owing to their different textures.CT and MRI facilitate the identification of foreign body materials.Plant-derived foreign bodies should be completely removed,and surgical treatment is a complicated process.

Minerogenic System of Magnesian Nonmetallic Deposits in Early Proterozoic Mg-rich Carbonate Formations in Eastern Liaoning Province

In the early Proterozoic the Li'eryu Formation and Dashiqiao Formation of eastern Liaoning province, China, there are distributed Mg-rich carbonate rock formations, in which large to superlarge deposits of boron, magnesite, talc, Xiuyan jade etc. occur. The formation of these magnesian nonmetallic deposits was related to early Proterozoic evaporates; then these deposits underwent reworking of regional metamorphism and hydrothermal metasomatism during the Lüliang orogeny and tectono-magmatism during the Indosinian-Yanshanian. Among other things, the Mg-rich carbonates formations, minerogenetic structures and ore-forming fluids played a controlling role in the formation of the mineral deposits. Therefore, it can be concluded that the mineral deposits are products of combined processes of the coupling of ore source field, fluid field, thermal field (energy field) and stress field under certain time-space conditions in the early Proterozoic and the late-stage superimposed reworking of tectono-magmatism.

Control of nonmetallic inclusions of non-oriented silicon steel sheets by the rare earth treatment

Based on the industrial production of non-oriented silicon steel, the rare earth （RE） treatment during the Ruhrstahl Heraeus （RH） refining process was studied. The morphology and the size distribution were observed for the steel specimens treated with different RE treatment conditions. Furthermore, the formation and change of the nonmetallic inclusion characteristics of finished steel sheets after the RE treatment were discussed. The results have shown that in the present work,the suitable RE metal additions are 0.6 -0.9 kg/t steel. After the suitable RE treatment,the formation of AIN and MnS inclusions were restrained, and the aggregation, flotation and removal of nonmetallic inclusions were efficiently promoted and the cleanliness of liquid steel was significantly increased. Meanwhile, the total oxygen concentration reached the minimum value and thle desulfurization efficiency was optimal ,and the type of main inclusions was approximately spherical or elliptical spherical RE radicle inclusions whose size was relatively large.

Dynamic mass variation and multiphase interaction among steel, slag, lining refractory and nonmetallic inclusions: Laboratory experiments and mathematical prediction

The mass transfer among the multiphase interactions among the steel, slag, lining refractory, and nonmetallic inclusions during the refining process of a bearing steel was studied using laboratory experiments and numerical kinetic prediction. Experiments on the system with and without the slag phase were carried out to evaluate the influence of the refractory and the slag on the mass transfer. A mathematical model coupled the ion and molecule coexistence theory, coupled-reaction model, and the surface renewal theory was established to predict the dynamic mass transfer and composition transformation of the steel, the slag, and nonmetallic inclusions in the steel. During the refining process,Al_(2)O_(3) inclusions transformed into Mg O inclusions owing to the mass transfer of [Mg] at the steel/refractory interface and(Mg O) at the slag/refractory interface. Most of the aluminum involved in the transport entered the slag and a small part of the aluminum transferred to lining refractory, forming the Al_(2)O_(3) or Mg O·Al_(2)O_(3). The slag had a significant acceleration effect on the mass transfer. The mass transfer rate(or the reaction rate) of the system with the slag was approximately 5 times larger than that of the system without the slag. In the first 20 min of the refining, rates of magnesium mass transfer at the steel/inclusion interface, steel/refractory interface, and steel/slag interface were x, 1.1 x, and 2.2 x,respectively. The composition transformation of inclusions and the mass transfer of magnesium and aluminum in the steel were predicted with an acceptable accuracy using the established kinetic model.

Simulation research on monomer agglomeration of nonmetallic inclusions in steel with a diffusion limited aggregation model

The monomer agglomeration of nonmetallic inclusions was simulated with a diffusion limited aggregation （DLA） model of the fractal theory. The simulation study with a random two-dimensional diffusion was carried out. The results indicate that the DLA model can be used for the simulation of agglomeration behavior of the cluster-type inclusions. The morphology of clusters was observed with SEM and compared with the simulated agglomerates. The modelling procedure of the DLA model is applicable for the agglomeration process. The uncertainty of agglomeration process and the persuasive average agglomerative ratio was analyzed. The factors about the agglomerative ratio with the collision path distance and the size of particles or seed were discussed. The adherence of the nonmetallic inclusions on the dam, the weir and the walls of a tundish, and the absorption of inclusions by stopper or nozzle were also discussed.

Evolution of plasticized MnO–Al2O3–SiO2-based nonmetallic inclusion in 18wt%Cr-8wt% Ni stainless steel and its properties during soaking process

The properties of MnO–Al2O3–SiO2-based plasticized inclusion are likely to change during soaking process due to its low melting point. In this study, the evolution of the MnO–Al2O3–SiO2-based inclusion of 18 wt%Cr-8 wt%Ni stainless steel under isothermal soaking process at 1250°C for different times was investigated by laboratory-scale experiments and thermodynamic analysis. The results showed that the inclusion population density increased at the first stage and then decreased while their average size first decreased and then increased. In addition, almost no Cr2O3-concentrated regions existed within the inclusion before soaking, but more and more Cr2O3 precipitates were formed during soaking. Furthermore, the plasticity of the inclusion deteriorated due to a decrease in the amount of liquid phase and an increase in the high-melting-pointphase MnO–Cr2O3 spinel after the soaking process. In-situ observations by high-temperature confocal laser scanning microscopy(CLSM) confirmed that liquid phases were produced in the inclusions and the inclusions grew rather quickly during the soaking process. Both the experimental results and thermodynamic analysis conclude that there are three routes for inclusion evolution during the soaking process. In particular, Ostwald ripening plays an important role in the inclusion evolution, i.e., MnO–Al2O3–SiO2-based inclusions grow by absorbing the newly precipitated smaller-size MnO–Cr2O3 inclusions.

Cutting of nonmetallic materials using Nd:YAG laser beam

This study deals with Nd：YAG laser cutting nonmetallic materials, which is one of the most important and popular industrial applications of laser. The main theme is to evaluate the effects of Nd：YAG laser beam power besides work piece scanning speed. For approximate cutting depth, a theoretical study is conducted in terms of material property and cutting speed. Results show a nonlinear relation between the cutting depth and input energy. There is no significant effect of speed on cutting depth with the speed being larger than 30 mm/s. An extra energy is utilized in the deep cutting. It is inferred that as the laser power increases, cutting depth increases. The experimental outcomes are in good agreement with theoretical results. This analysis will provide a guideline for laser-based industry to select a suitable laser for cutting, scribing, trimming, engraving, and marking nonmetallic materials.

AN ANALYSIS OF THE GEOTECTONICCONDITIONS OF FORMATION OF NONMETALLIC ORES ON THE WESTERN MARGIN OF THE DONGTING DIWA

There is a close relationship between occurrence of nonmetallic minerals and tectonic evolution of geosyncline, platform and diwa (geodepression) on the western margin of the Dongting diwa. Some results that (1) diwa tectonics is berfeficial for formation and preservation of nonmetallic minerals and (2) volcano-sedimentary altered ore deposits, saline deposits and organo-sedimentary ore deposits can be often found in diwa basins are gained.

Density Functional Theoretical Study of 5 ,5 '-Azotetrazolate Nonmetallic Salts

The structures, infrared spectra and cation stability of seven 5,5′-azotetrazolate nonmetallic salts are investigated by using B3LYP method with 6-311+G (d) basis set. The salts are guanidinium (GZT), aminoguanidinium (AGZT), diaminoguanidinium (DAGZT), triaminoguanidinium (TAGZT), azidoformamidinium (AFZT), ammonium (AZT), and hydrazinium (HZT), respectively. The calculated results indicate that the carbon and nitrogen atoms of the cations in seven nonmetallic salts are characterized to be sp2 hybrid atoms, and the ranges of characteristic absorption peaks in IR spectra of the seven nonmetallic salts are approximative consistent. All their cations are stable and their stabilities decrease with the increase in their nitrogen contents.

Progress on Preparation of Refractory Powder Using Nonmetallic Minerals and Its Applications

This review summarized the recent advances in the utilization of nonmetallic minerals and their applications for fabrication of unfired refractories.The preparation of refractory powder utilizing cheap nonmetallic minerals of zircon,low-grade bauxite and quartz was discussed,respectively.The preparation of three unfired SiC-based refractories：SiC-SiAlON-ZrN,Al2O3-SiC/β-SiAlON/Ti（C,N）-C,and Al2O3-SiC-Si3N4 using the as-prepared refractory powders was introduced.

High Conductivity Water Treatment Using Water Surface Discharge with Nonmetallic Electrodes

Although electrohydraulic discharge is effective for wastewater treatment,its application is restricted by water conductivity and limited to the treatment of low conductivity water. For high conductivity water treatment,water-surface discharge is the preferred choice.However. the metallic electrodes are easily corroded because of the high temperature and strong oxidative environment caused by gas phase discharge and the electrochemical reaction in water.As a result. the efficiency of the water treatment might be affected and the service life of the reactor might be shortened.In order to avoid the corrosion problem,nonmetallic electrode water-surface discharge is introduced into high conductivity water treatment in the present study.Carbon-felt and water were used as the high voltage electrode and ground electrode,respectively.A comparison of the electrical and chemical characteristics showed that nonmetallic electrode discharge maintained the discharge characteristics and enhanced the energy efficiency,and furthermore,the corrosion of metal electrodes was avoided.

Nonmetallic inclusions in SUS304 strip produced by twin-roll strip casting

The shape, type, content, and dimension of nonmetallic inclusions in SUS304 strip produced by twin-roll strip casting were studied using scanning electron microscopy （SEM）. The results show that the inclusions are mainly spherical Al2O3 and complex oxides composed of MnO, Al2O3 , and SiO2. The percentage of fine oxides smaller than 3 μm reaches up to 51.8%. The theoretical calculations show that fine oxides have precipitated during solidification. Therefore, it is concluded that during twin-roll strip casting, because of high cooling rate, the size of inclusions precipitated during solidification decreases, and the amount increases.

Physical Simulation of Nonmetallic Particle Movement in Al Melt under Electromagnetic Field

Physical simulation is used to study the movement of nonmetallic particles in Al melt in electro- magnetic field. It is found that the terminal velocity of particles in different Reynolds number range has different functions. By confirming drag force coefficient of nonmetallic particles with Reynolds number in the range of 0.2-10 and 10-25 respectively, two functions of terminal ve- locity for spherical nonmetallic particles have been got accordingly, which provide a theoretical basis for separating nonmetallic inclusions from Al melt in electromagnetic field.

STUDIES ON THE FROTH CHARACTERISTICS OF COMPOSITE COLLECTORS IN NONMETALLIC MINERAL FLOTATION

The flotation results of a phosphate ore are improved by replacing the conventional collectors of fatty acids with composite collectors. The synergistic effect on the froth characteristics in systems using composite collectors has then been studied, and the concept of 'mixed hemimicellae' has been proposed in the adsorption of composite collectors at the air/solution interfaces.

The Minerogenetic Series of Nonmetallic Mineral Deposits of China

Owing to the internal relationship between material sources or mineralization ways and the difference ofmineralization micro-environments or the change of constraints. certain types of nonmetallic mineral depositsare regularly formed either simultaneously or in successive order under the control of certain association ofmineralization processes in a certain geotectonic environment, thus forming a minerogenetic series ofnonmetallic mineral deposits. The geological setting that controls the formation of minerogenetic series is mosttruly recorded in ore-bearing formations. while the mineralization processes which are associated or surely suc-cessive are the indispensable prerequisite for the formation of the various mineral deposits of a minerogeneticseries. Therefore, the minerogenetic series of nonmetallic mineral deposits can be classified according tomineral-bearing formations and mineralization processes. Based on available data. 13 minerogenetic series aredistinguished in China. The study of minerogenetic series may not only result in the enrichment of the theory ofmineral deposits but also help direct mineral prospecting and give guidance in the integrated development andutillization of mineral resources.

Advanced Organic Materials for Nonmetallic Charge Carrier-Based Batteries

Organic electrode materials(OEMs),withmerits of structural diversity,molecular-level controllability,resource abundance,and environmental friendliness,have become a promising electrode candidate for low-carbon renewable batteries.Safer,environmentally benign,and sustainable aqueous rechargeable batteries are particularly appealing for large-scale energy storage applications.This review aims to provide an insightful discussion of OEMs in nonmetallic charge carrier-based batteries,especially for the application in aqueous rechargeable systems.The emerging application of OEMs in versatile aqueous batteries will be analyzed emphatically,including aqueous proton batteries,aqueous ammonium-ion batteries,and air self-charging batteries.We expect that this review can serve as a guide for the future development of OEMs in nonmetallic charge carrier-based batteries and provide inspiration for unmet challenges.

Distribution of nonmetallic inclusions in molten steel under hot-top pulsed magneto-oscillation treatment

To control the distribution of nonmetallic inclusions in molten developed method, hot-top pulsed magneto-oscillation （HPMO）, steel is of highly commercial importance. A newly was employed to control nonmetallic inclusions in a medium-carbon steel ingot. The experimental results present that the position of nonmetallic inclusions of spinel （Al-Mg-O） and Mn-S inclusions is significantly influenced by HPMO. The number of nonmetallic inclusions gradually increased from the lateral wall to the center of ingot along the radial direction under the impact of HPMO treatment, whereas this distribution trend cannot be observed in the reference sample without HPMO treatment. In addition, the number of inclusions along vertical direction is proportional to the height of ingot, especially for the inclusions with the size of larger than 10 pro. It indicates that the application of HPMO can push away inclusions from lateral to center, and then the expelled inclusions aggregate and rise up to the top of ingot.

Evolution and control of nonmetallic inclusions in FeSiB alloy

Inclusions have a great infuence on the quality of FeSiB amorphous ribbon.The evolution behavior of inclusions was analyzed.The results show that the spherical and elliptical inclusions,consisting of Al2O3 and SiO2,mainly come from industrial pure iron.Ellipsoidal inclusions of 20-30μm in pure iron were removed by foatation during the smelting process,and spherical inclusions of 1-3μm combined with deoxidized products in FeSiB melt form Al2O3·SiO2 and CaO·Al2O3·SiO2 inclusions.Some inclusions accumulated on the inner wall of the nozzle during the spraying process,and others fowed out of the nozzle and remained in FeSiB amorphous ribbon.By controlling the total oxygen content in industrial pure iron to 31×10^-6,clogging on the inner wall of the nozzle can be reduced and the free surface smoothness of the amorphous ribbon can be improved.

Quantitative Study on Nonmetallic Inclusion Particles in Steels by Automatic Image Analysis With Extreme Values Method

The presence of nonmetallic inclusion particles which appear during steelmaking process is harmful to the properties of steels, which is mainly as a function of some aspects such as size, volume fraction, shape, and distribution of these particles. The automatic image analysis technique is one of the most important tools for the quantitative determination of these parameters. The classical Student approach and the Extreme Values Method （EVM） were used for the inclusion size and shape determination and the evaluation of distance between the inclusion particles. The results thus obtained indicated that there were significant differences in the characteristics of the inclusion particles in the analyzed products. Both methods achieved results with some differences, indicating that EVM could be used as a faster and more reliable statistical methodology.