Effect of MnO Content on the Interfacial Property of Mold Flux and Steel

Wanlin Wang,Jingwen Li,Lejun Zhou,Jian Yang 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.4

The interfacial property between liquid mold flux and steel has significant impact on the quality of casting slab, and this property is mainly determined by the chemical composition of mold flux and the reaction between the flux and steel. The effect of MnO content on the contact angle and interfacial tension between liquid mold flux and ultra-low carbon steel was investigated by sessile drop method in this article, and the results suggested that both the contact angle and interfacial tension decreased with the increase of MnO content in the mold flux. The increase of Si and Mn and the reduction of Al and Ti in the interaction layer were caused by the chemical reactions occurred in the vicinity of interface between mold flux and steel substrate. Besides, the thickness of the interaction layer increased from 4 μm to 7 μm, then to 9 μm, 11 μm and 15 μm when the MnO content was added from 1 wt% to 3 wt%, then to 5 wt%, 7 wt%, and 9 wt% due to the fact that MnO can simplify the polymerized structure of the melt and improve the penetrability of molten mold flux to make the interfacial reaction easier.

Effect of Mold Flux Melting and Crystal Fraction Dissolution on Radiative Heat Transfer in Continuous Casting

Wanlin Wang,Lejun Zhou,Gu Kezhuan 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.6

A mold flux is widely used to modify heat transfer rates in continuous casting, and crystallization of a mold flux has been identified as a primary factor that influences heat flux from the strand to the mold. By using an infrared radiation emitter, a radiative heat flux was applied to a copper mold covered with solid mold flux disk to simulate the heat transfer phenomena in continuous casting. By this technique it is possible to have a liquid layer, a crystalline layer and a glassy layer in contact with one another and, by varying the energy input, it is possible to study the dynamic nature of the film and its effect on the radiative and overall heat transfer rate. A general heat transfer model was also developed to allow the prediction of the effect of varying the thickness of the three potential layers in the flux film.

Radiative Heat Transfer Behavior of Mold Fluxes for Casting Low and Medium Carbon Steels

Wang, Wanlin,Gu, Kezhuan,Zhou, Lejun,Ma, Fanjun,Sohn, Il,Min, Dong Joon,Matsuura, Hiroyuki,Tsukihashi, Fumitaka The Iron and Steel Institute of Japan 2011 ISIJ international Vol.51 No.11

<P>An investigation was carried out to study the radiative heat transfer behavior of two typical mold fluxes for casting low (Flux1) and medium (Flux2) carbon steels. By using an infrared radiation emitter, a radiative heat flux was applied to a copper mold covered with solid mold flux disk to simulate the heat transfer phenomena in continuous casting. The effective thermal conductivities were determined by measuring the temperature gradient in the copper mold system. It was found that the solid crystalline mold Flux2 for casting medium carbon steel has a better capability to transfer heat than that of solid crystalline Flux1, while their glassy fluxes behave similar capability. The DHTT (Double Hot Thermocouple Technique) was employed in this paper to study the heat transfer capability of the crystalline mold fluxes. DHTT measurements suggested that the thermal diffusivity of crystalline sample of Flux2 is higher than that of Flux1. The XRD and SEM results were indicated that the precipitated crystalline phase for Flux1 is only granular cuspidine, Ca<SUB>4</SUB>Si<SUB>2</SUB>O<SUB>7</SUB>F<SUB>2</SUB>, while those for Flux2 are consisted of dendritic cuspidine, Ca<SUB>4</SUB>Si<SUB>2</SUB>O<SUB>7</SUB>F<SUB>2</SUB> and gehlenite, Ca<SUB>2</SUB>Al<SUB>2</SUB>SiO<SUB>7</SUB>.</P>

Modeling Surface Tension of Multicomponent Liquid Steel Using Modified Quasichemical Model and Constrained Gibbs Energy Minimization

김성광,Wanlin Wang,강윤배 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.4

Surface tension of multicomponent liquid steel was calculated based on the concept proposed by Butler, which assumes a chemical equilibrium between a bulk phase and a surface phase of a monolayer. Requirement for the calculation of the surface tension was categorized as: 1) accurate description of partial excess Gibbs energies of solutes in the liquid steel, in particular for those of non-metallic solutes such as S, C, etc., 2) physical properties of pure components, such as surface tension and molar volume, and 3) possibility of solving a series of Butler equations for multicomponent liquid steel. In the present study, it is proposed to use the Modified Quasichemical Model in order to describe the partial excess Gibbs energies of solutes, and to use the Constrained Gibbs Energy Minimization in order to solve equilibrium between the bulk and the surface phases of the multicomponent liquid steel. Physical properties of non-stable pure components such as S, C, were treated as variables to reproduce known experimental data in binary systems. The proposed method can be easily extended into multicomponent liquid steel. Examples of the surface tension calculations are presented.

Effect of Basicity and B2O3 on Viscosity, Melting and Crystallization Behaviors of Low Fluorine Mold Fluxes for Casting Medium Carbon Steels

Lejun Zhou,Wanlin Wang,Boxun Lu,Guanghua Wen,Jian Yang 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

As potential substitutes for fluorides, the influences of basicity and B2O3 content on viscosity, melting andcrystallization behaviors of low fluorine mold fluxes for casting medium carbon steels were investigatedby using Brookfield viscometer and Single Hot Thermocouple Technique in this study. Results suggestedthat, the break temperature, crystallization temperature and critical cooling rate of low fluorine mold fluxeswere increased with the increase of basicity; while they were decreased with the further addition of B2O3. Meantime, the viscosity and melting temperature range were first attenuated, and then increased greatlywith the increase of basicity; however, they would tend to be reduced with the addition of B2O3 content. Also, it was found that the viscosity of mold flux is not only decided by the degree of polymerization ofsilicate structure, but also greatly affected by its crystallization behavior.

A Multimodal Fusion Method Based on a Rotation Invariant Hierarchical Model for Finger-based Recognition

( Zhen Zhong ),( Wanlin Gao ),( Minjuan Wang ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.1

Multimodal biometric-based recognition has been an active topic because of its higher convenience in recent years. Due to high user convenience of finger, finger-based personal identification has been widely used in practice. Hence, taking Finger-Print (FP), Finger-Vein (FV) and Finger-Knuckle-Print (FKP) as the ingredients of characteristic, their feature representation were helpful for improving the universality and reliability in identification. To usefully fuse the multimodal finger-features together, a new robust representation algorithm was proposed based on hierarchical model. Firstly, to obtain more robust features, the feature maps were obtained by Gabor magnitude feature coding and then described by Local Binary Pattern (LBP). Secondly, the LGBP-based feature maps were processed hierarchically in bottom-up mode by variable rectangle and circle granules, respectively. Finally, the intension of each granule was represented by Local-invariant Gray Features (LGFs) and called Hierarchical Local-Gabor-based Gray Invariant Features (HLGGIFs). Experiment results revealed that the proposed algorithm is capable of improving rotation variation of finger-pose, and achieving lower Equal Error Rate (EER) in our homemade database.

Effect of basicity and B₂O₃ on the viscosity and structure of fluorine-free mold flux

Zhang, Lei,Wang, Wanlin,Xie, Senlin,Zhang, Kaixuan,Sohn, Il Elsevier 2017 Journal of non-crystalline solids Vol.460 No.-

<P><B>Abstract</B></P> <P>The effect of basicity (weight ratio of CaO/SiO<SUB>2</SUB>) and B<SUB>2</SUB>O<SUB>3</SUB> on the viscosity and structure of Fluorine-free mold flux for the casting of medium carbon steels was conducted in this article, through the rotating cylinder method combined with the Fourier transform infrared (FTIR) spectroscopy. The results showed that, with the increase of basicity, the viscosity of mold flux was attenuated dramatically, and then kept constant or slight increased in the low temperature region. The reason could be explained as the degree of polymerization (DOP) of the network structure was first reduced significantly with the addition of basicity, and then the further depolymerization is less pronounced with the further increase of basicity. Beside the formation of high melting point substance leads to the slight increase of viscosity. Moreover, it suggested that the viscosity of mold flux is decreased with the addition of B<SUB>2</SUB>O<SUB>3</SUB> content, due to the fact that B<SUB>2</SUB>O<SUB>3</SUB> is a low melting point oxide which could substantially lower the break temperature of mold flux. The result of FTIR indicated B<SUB>2</SUB>O<SUB>3</SUB> acts as network former, and tends to form [BO<SUB>3</SUB>]-trihedral and [BO<SUB>4</SUB>]-tetrahedral structural units, which would connect with each other to form some simple network structure such as diborate or pentaborate. With the addition of B<SUB>2</SUB>O<SUB>3</SUB>, the free oxygen ions (O<SUP>2−</SUP>) would depolymerize the diborate structural unit, and the depolymerized diborate would link again with free [BO<SUB>3</SUB>]-trihedral to form complex pentaborate groups. Moreover, the effect of above addition on the apparent activation energy for viscous flow and break temperature of mold flux also were discussed. The results obtained in this paper provide the detailed study of the structure evolution of Fluorine-free mold flux when B<SUB>2</SUB>O<SUB>3</SUB> is added.</P>

Effect of ZrO₂ on the Melting, Viscosity, and Crystallization Behaviors of Fluorine-Free Mold Flux for Casting Medium Carbon Steels

Zhou, Lejun,Li, Huan,Wang, Wanlin,Sohn, Il STAHLEISEN GMBH 2017 STEEL RESEARCH INTERNATIONAL Vol.88 No.9

Deep Learning based Rapid Diagnosis System for Identifying Tomato Nutrition Disorders

( Li Zhang ),( Jingdun Jia ),( Yue Li ),( Wanlin Gao ),( Minjuan Wang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.4

Nutritional disorders are one of the most common diseases of crops and they often result in significant loss of agricultural output. Moreover, the imbalance of nutrition element not only affects plant phenotype but also threaten to the health of consumers when the concentrations above the certain threshold. A number of disease identification systems have been proposed in recent years. Either the time consuming or accuracy is difficult to meet current production management requirements. Moreover, most of the systems are hard to be extended, only detect a few kinds of common diseases with great difference. In view of the limitation of current approaches, this paper studies the effects of different trace elements on crops and establishes identification system. Specifically, we analysis and acquire eleven types of tomato nutritional disorders images. After that, we explore training and prediction effects and significances of super resolution of identification model. Then, we use pre-trained enhanced deep super-resolution network (EDSR) model to pre-processing dataset. Finally, we design and implement of diagnosis system based on deep learning. And the final results show that the average accuracy is 81.11% and the predicted time less than 0.01 second. Compared to existing methods, our solution achieves a high accuracy with much less consuming time. At the same time, the diagnosis system has good performance in expansibility and portability.