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International Journal of Minerals,Metallurgy and Materials 2023年第2期30卷 345-353页

作者： Changyu ren Caide Huang Lifeng Zhang ying ren School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Shougang Jingtang United Iron and Steel Co. Ltd.Tangshan 063200China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The dissolution kinetics of Al_(2)O_(3) in CaO-Al_(2)O_(3) SiOslags was studied using a high-temperature confocal scanning laser microscope at 1773 to 1873 *** results show that the controlling step during the Al_(2)O_(3) dissolution was the diffusionin molten *** was found that the dissolution curves of Al_(2)O_(3) particles were hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al_(2)O_(3) ratio of slag.A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al_(2)O_(3) in *** coefficients of Al_(2)O_(3) in slag were calculated as 2.8×10to 4.1×10m~2/s at the temperature of 1773-1873 *** dissolution rate of Al_(2)O_(3) increased with higher temperature,CaO/Al_(2)O_(3),and particle size.A new model was shown to be v_(Al_(2)O_(3))=0.16×r_(0)^(1.58)×x^(3.52)×(T-T_(mp))^(1.11)to predict the dissolution rate and the total dissolution time of Al_(2)O_(3) inclusions with various sizes,where vAl_(2)O_(3) is the dissolution rate of Al_(2)O_(3) in volume,μm^(3)/s;x is the value of CaO/Al_(2)O_(3) mass ratio;R_(0) is the initial radius of Al_(2)O_(3),μm;T is the temperature,K;T_(mp) is the melting point of slag,K.

关键词： inclusion dissolution kinetics confocal scanning laser microscope refining slag

Modeling reoxidation behavior of Al-Ti-containing steels by CaO-Al2O3-MgO-SiO2 slag

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Journal of Iron and Steel Research International 2018年第2期25卷 146-156页

作者： ying ren Li-feng Zhang ying Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083 China

A kinetic model was developed using FactSage Macro Processing to simulate the reoxidation of Al-Ti-containing steels by CaO-Al2O3-SiO2-MgO slags. The calculated results show a good agreement with the experimental data. Thus, the developed kinetic model can be used to predict changes in slag, steel, and inclusion compositions during the reaction process. During the slag reoxidation process, the reactions occurring at slag-steel interface and in the bulk steel were confirmed to be the reduction of SiO2 by [All and [Til and the self-dissociation of SiO2 into [Si] and [O]. Increasing the ratio of CaO to SiO2 in the slag can significantly suppress the self-dissociation of SiO2 in the slag and lower the amount of inclusions produced during reoxidation. The formed inclusions changed from solid Al2O3 to Al2O3-TiOx inclusions, which was mainly dependent on the w（[Al]） and w（[Ti]）. The amount of inclusions was obviously influenced by the composition of the top slag.

关键词： Kinetic model Slag Inclusion Reoxidation Al-Ti-containing steel

Distribution of TiN inclusions in Ti-stabilized ultra-pure ferrite stainless steel slab

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Journal of Iron and Steel Research International 2019年第9期26卷 962-972页

作者： Hao-jian Duan ying Zhang ying ren Li-feng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In order to clarify and control the silver defect on surface of cold-rolled sheet of the Ti-stabilized ultra-pure ferrite stainless steel, the distribution of TiN inclusions on the cross section of hot-rolled plate was studied using automated scanning electron microscopy/energy-dispersive X-ray spectroscopy inclusion analysis (ASPEX 1020 system). It was found that the number density decreases sharply from the surface to the center of the hot-rolled plate, whereas the average size increases. Then, the distribution of TiN inclusions on the cross section of continuously cast slab was investigated. Similarly, numerous small-sized TiN inclusions were generated at the subsurface of the slab. The average size rapidly increased and the number density dramatically decreased from the subsurface to 1/4 thickness, while from 1/4 thickness to 1/2 thickness, the increase in average size and the decrease in number density were slight. Thermodynamics results showed that TiN inclusion was formed below the liquidus temperature, which indicated that TiN inclusions could not be formed during secondary refining. Considering the microsegregation of solute elements and the equilibrium of TiN formation during solidification, TiN precipitated in the mushy zone when the solid fraction was close to 0.2. The growth of TiN was analyzed based on the diffusion-controlled growth model. With the increase in cooling rate, the time for TiN growth decreased and the size of TiN inclusions was diminished, which revealed the size distribution of TiN inclusions in the cast slab qualitatively.

关键词： TiN inclusion Ti-stabilized ultra-pure ferrite stainless steel Distribution in slab Thermodynamics Diffusion-controlled growth model

New Fossil Palaeontinids from the Middle Jurassic of Daohugou,Inner Mongolia,China (Insecta,Hemiptera)

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Acta Geologica Sinica(English Edition) 2009年第1期83卷 33-38页

作者： WANG ying ren Dong Key Lab of lnsect Evolution and Environmental Changes Capital Normal University Beijing 100048 China

Two new genera and species of fossil Palaeontinidae are described from Daohugou Village, Inner Mongolia, China： Cladocossus undulatus gen. et sp. nov. and Cricocossus paradoxus gen. et sp. nov. Both new genera are described based on well-preserved forewings. This discovery confirms the high diversity of palaeontinids during the Middle Jurassic. Both specimens have interesting modal structures which are new to Palaeontinidae： M five-branched and M3 with two branches. Based on this character, wing structural characteristic is discussed.

关键词： morphology taxonomy palaeontology Cicadomorpha Mesozoic

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

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International Journal of Minerals,Metallurgy and Materials 2021年第8期28卷 1298-1308页

作者： Ju-jin Wang Li-feng Zhang Gong Cheng Qiang ren ying ren School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China

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.

关键词： mass transfer steel slag lining refractory nonmetallic inclusions kinetic model

Prediction of spatial distribution of the composition of inclusions on the entire cross section of a linepipe steel continuous casting slab

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Journal of Materials Science & Technology 2021年第2期61卷 147-158页

作者： Qiang ren Yuexin Zhang ying ren Lifeng Zhang Jujin Wang Yadong Wang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China

In the current study, the transformation in the composition of non-metallic inclusions from the molten steel to the solidified steel was studied and the composition distribution of inclusions on the cross section of a linepine continuous casting slab was predicted. During cooling and solidification of the continuous casting strand, Al_(2)O_(3)-CaO inclusions reacted with the bulk steel and transformed to CaS-Al_(2)O_(3)-MgO-(CaO) ones in the continuous casting slab. The composition of inclusions on the cross section of the slab varied with locations due to the varied cooling rate. A model was established to predict the distribution of the composition of inclusions on the cross section of the continuous casting slab, coupling solidification and heat transfer of the continuous casting slab, the kinetic mass transfer of the dissolved elements in the solid steel, and thermodynamic calculation of inclusion transformation at different temperatures. The composition transformation of inclusions mainly occurred at the temperature between the liquidus and solidus of the linepipe steel. Inclusions were mainly CaS-Al_(2)O_(3)-MgO-(CaO) in slab center and were MgO-Al_(2)O_(3)-CaO-CaS within the subsurface of the slab. In the slab, the transformation fraction of inclusions was less than 10 % at corners while it reached 70 % at 50 mm below the surface of the slab.

关键词： Inclusions Linepipe steel Continuous casting slab Mass transfer Thermodynamics Kinetics

On U-ample ω-semigroups

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Frontiers of Mathematics in China 2013年第6期8卷 1391-1405页

作者： Siyao MA Xueming ren ying YUAN Department of Mathematics Xi'an University of Architecture and Technology Xi'an 710055China

The investigation of U-ample ω-semigroups is initiated. After obtaining some properties of such semigroups, a structure of U-ample ω-semigroups is established. It is proved that a semigroup is a U-ample ω-semigroup if and only if it can be expressed by WBR（T, 0）, namely, the weakly Bruck-Reilly extensions of a monoid T. This result not only extends and amplifies the structure theorem of bisimple inverse ω-semigroups given by N. R. Reilly, but also generalizes the structure theorem of ,-bisimple type A ω-semigroups given by U. Asibong-Ibe in 1985.

关键词： Bisimple inverse ω-semigroups weakly U-abundant semigroups,Ehresmann semigroups U-ample ω-semigroups

Influence of substituting B_(2)O_(3) with Li_(2)O on the viscosity,structure and crystalline phase of low-reactivity mold flux

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International Journal of Minerals,Metallurgy and Materials 2023年第7期30卷 1320-1328页

作者： Rongzhen Mo Xubin Zhang ying ren Junjie Hu Lifeng Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Lecture at College of Materials Science and Engineering Chongqing UniversityChongqing 400030China School of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The low-reactivity mold flux with low SiO_(2)content is considered suitable for the continuous casting of high-aluminum steel since it can significantly reduce the reaction between Al in steel and SiO_(2)in mold ***,the traditional low-reactivity mold flux still presents some problems such as high viscosity and strong crystallization *** this study,the co-addition of Li_(2)O and B_(2)O_(3)in CaO–Al_(2)O_(3)–10wt%Si O_(2)based low-reactivity mold flux was proposed to improve properties of mold flux for high-aluminum steel,and the effect of Li_(2)O replacing B_(2)O_(3)on properties of mold flux was *** viscosity of the mold flux with 2wt%Li_(2)O and 6wt%B_(2)O_(3)reached a minimum value of 0.07 Pa·*** break temperature and melting point showed a similar trend with the ***,the melt structure and precipitation of the crystalline phase were studied using Raman and X-ray diffraction spectra to better understand the evolution of *** demonstrated that with increasing Li_(2)O content in the mold flux from 0 to 6 wt%,the degree of polymerization of aluminate and the aluminosilicate network structure increased because of increasing Li+released by Li_(2)O,indicating the added Li_(2)O was preferentially associated with Al^(3+)as a charge *** precipitation of LiAlO_(2)crystalline phase gradually increased with the replacement of B_(2)O_(3)by Li_(2)***,Li_(2)O content should be controlled below 2wt%to avoid LiAlO_(2)precipitation,which was harmful to the continuous casting of highaluminum steels.

关键词： low-reactivity mold flux viscosity structure crystalline phase

Effect of nozzle type on fluid flow, solidification, and solute transport in mold with mold electromagnetic stirring

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Journal of Iron and Steel Research International 2022年第2期29卷 237-246页

作者： Ya-dong Wang Li-feng Zhang Wen Yang ying ren School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China State Key Lab of Metastable Materials Science and Technology School of Mechanical EngineeringYanshan UniversityQinhuangdao066004HebeiChina

The mathematical model of coupling fluid flow,heat transfer,solidification,solute transport,and the electromagnetic field of the bloom in the upper part of the strand was established with three nozzle ***,the flow field,distribution of the temperature,solidification,and macrosegregation of carbon were investigated and compared by numerical *** the case of the straight submerged entry nozzle(SEN),the molten steel flows down deep into the liquid pool,and the depth of the jet flow reaches about 1.0 m beneath the *** jetting zone is the high-temperature *** the case of two-port SEN and four-port SEN,the flow patterns and distribution of temperature in the central longitudinal section are *** jet flow impinges directly on the initially solidified shell and then it is divided into two longitudinal *** heat of molten steel is dissipated along with the longitudinal *** negative segregation band was generated near the bloom surface due to the washing effect by the rotating flow at the solidification front with three nozzle *** negative segregation deteriorates gradually with the number of ports decreasing.

关键词： Submerged entry nozzle Fluid flow Solidification Solute transport Mold electromagnetic stirring

Special issue on continuous casting

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Journal of Iron and Steel Research International 2022年第1期29卷 1-2页

作者： Le-jun Zhou ying ren Pei-yuan Ni School of Metallurgical and Environment Central South UniversityChangsha 410083HunanChina School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Education Ministry School of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina

Continuous casting is considered to be one of the most important innovations in steel industry since it is first propagated by Henry Bessemer in *** has many benefits,including(Ⅰ)increased yield,(Ⅱ)improved product quality,(Ⅲ)energy saving,(Ⅳ)less pollution,(Ⅴ)reduced costs,(Ⅵ)better working conditions,***,more than 98% of crude steel output in the world is produced through the continuous casting process.

关键词： casting steel process.