检索结果-南通市图书馆

Journal of Materials Science & Technology 2022年第7期102卷 105-114页

作者： Shucai Zhang Jiangtao Yu Huabing Li Zhouhua Jiang Yifeng Geng Hao Feng Binbin Zhang Hongchun Zhu School of Metallurgy Northeastern UniversityShenyang 110819China school of Materials and metallurgy University of Science and Technology LiaoningAnshan 114051China

The influence of Ce addition on the solidification structure and σphase of super austenitic stainless steel S32654 was systematically investigated via microstructural characterization and thermodynamic calcula- tion. The results indicate that a small addition of Ce could modify MgO and MnS into Ce-bearing inclu- sions Ce_(2)O_(3)and Ce_(2)O_(2)S. Ce addition led to noticeable refinement of both the dendrite structure and σphase. The refinement mechanism could be attributed to the combined actions of effective Ce-bearing inclusions and solute Ce. Effective Ce-bearing inclusions could serve as heterogeneous nucleation cores of austenite as well as σphase, which provided a favorable prerequisite for their refinement. Solute Ce significantly enhanced the undercooling degree of the system, further promoting dendrite structure re- finement. Meanwhile, solute Ce improved the eutectic precipitation conditions of σphase and further promoted its nucleation, while the dendrite refinement limited its growth space. Finally, more fine and dispersed σphase particles formed in S32654 with Ce addition. The refinement of dendrite structure and σ phase will reduce the temperature and time required for high-temperature homogenization, which is beneficial to the hot working of this steel.

关键词： Super austenitic stainless steel Cerium Solidification structure Sigma phase Refinement

Advance in carbonaceous-based scaffolds in constructing the stable composite Li metal anode

在线全文

学校读者我要写书评

暂无评论

新型炭材料（中英文） 2023年

作者： CHEN Yue ZHAO Lu-kang ZHOU Jun-long BIAN Yu-hua GAO Xuan-wen CHEN Hong LIU Zhao-meng LUO Wen-bin School of Metallurgy Northeastern University

Lithium metal batteries(LMBs) are considered as one of the ideal energy storage devices for post-lithium-ion batteries(LIBs) because they have a high energy density, high theoretical specific capacity, and low oxidation potential. Lithium metal anode(LMA), however face various obstacles, including low coulomb efficiency(CE), substantial volume expansion, the creation of lithium dendrites, security and stability issues, and a short service life, which hamper the practical deployment of LMBs. Carbon-based materials have been paid much attention owing to the advantages of low density, high mechanical strength, stable chemical properties, and large specific surface area. Establishing a composite carbonaceous LMA stands out among different tactics because of its attractive abilities to reduce volume expansion, lower the local current density, and offer active nucleation sites for uniform Li+ plating.The recent research advancement of composite carbonaceous LMA is evaluated, including carbonaceous composites, composites of elemental metals and their compounds with carbon-based materials, as well as their relationships to anode interface stability and structure. A summary and point of view are given about carbon-based materials as scaffolding for LMA.

关键词：

Cerium-modified amorphous manganese oxides for efficient catalytic removal of ozone

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2023年第9期131卷 151-161页

作者： Aijie Wang Hong Zhao Yu Wu Qiuyan Zhang Chong Han School of Metallurgy Northeastern UniversityShenyang 110819China

Manganese-based catalysts were widely developed for catalytic removal of ozone,and the low stability and water inactivation are major challenges.To improve removal performance of ozone,three methods were applied to modify amorphous manganese oxides,including acidification,calcination and Ce modification.The physiochemical properties of prepared samples were characterized,and the catalytic activity for ozone removal was evaluated.All modification methods can promote the removal of ozone by amorphous manganese oxides,and Ce modification showed the most significant enhancement.It was confirmed that the introduction of Ce markedly changed the amount and property of oxygen vacancies in amorphous manganese oxides.Superior catalytic activity of Ce-MnO_(x) can be ascribed to its more content and enhanced formation ability of oxygen vacancies,larger specific surface area and higher oxygen mobility.Furthermore,the durability tests under high relative humidity(80%)determined that Ce-MnO_(x) showed excellent stability and water resistance.These demonstrate the promising potential of amorphously Ce-modified manganese oxides for catalytic removal of ozone.

关键词： Amorphous manganese oxides Cerium Oxygen vacancy Ozone Stability

Effect of magnesium on microstructure and properties of 440C stainless bearing steel melted under pressurized conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2023年第4期30卷 808-824页

作者： Yang Li Chang-yong Chen Qi Wang Hao Yang Shuai Ma Meng Sun Zhou-hua Jiang School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The effects of magnesium(Mg)on the microstructure and properties of 440C stainless bearing steel melted under pressurized conditions were studied.Adding Mg improved the cleanliness of molten steel,modified the inclusions in steel,enhanced the distribution of carbides,and improved the mechanical properties and corrosion resistance of experimental steel.In detail,the contents of TO,S,and N in steel decreased from 0.0013 to 0.0003 wt.%,from 0.0032 to 0.0018 wt.%and from 0.0088 to 0.0049 wt.%,respectively.In addition,the transformation order of oxide inclusions in steel is Al_(2)O_(3)→MgO∙Al_(2)O_(3)→MgO,where the content of Mg in steel sharply increased from 0.00 to 29×10^(-4),81×10^(-4),and 160×10^(-4)wt.%,and the transformation order of S-containing inclusions in steel is MnS→Mg–S–Mn(–MgO)→Mg–O–S.Moreover,the number and size of inclusions and the proportion of large-size inclusions in steel decreased rapidly.Furthermore,the network structure of carbides in steel collapsed,the size of carbides was reduced,and the distribution was more uniform.Finally,the tensile strength,impact toughness,and pitting corrosion resistance of the experimental steel were significantly improved.

关键词： Magnesium Bearing steel Inclusion Carbide Corrosion resistance

Kinetics and mechanism of hexavalent chromium removal by basic oxygen furnace slag

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2016年第8期28卷 63-71页

作者： Chong Han Yanan Jiao Qianqian Wu Wangjin Yang He Yang Xiangxin Xue School of Metallurgy Northeastern University

Basic oxygen furnace slag（BOFS） has the potential to remove hexavalent chromium（Cr（VI））from wastewater by a redox process due to the presence of minerals containing Fe2＋. The effects of the solution p H, initial Cr（VI） concentration, BOFS dosage, BOFS particle size, and temperature on the removal of Cr（VI） was investigated in detail through batch tests. The chemical and mineral compositions of fresh and reacted BOFS were characterized using scanning electron microscope（SEM） equipped with an energy dispersive spectrometer（EDS）system and X-ray diffractometer（XRD）. The results show that Cr（VI） in wastewater can be efficiently removed by Fe2＋released from BOFS under appropriate acidic conditions. The removal of Cr（VI） by BOFS significantly depended on the parameters mentioned above. The reaction of Cr（VI） with BOFS followed the pseudo-second-order kinetic model. Fe2＋responsible for Cr（VI） removal was primarily derived from the dissolution of Fe O and Fe3O4 in BOFS. When H2SO4 was used to adjust the solution acidity, gypsum（Ca SO4·2H2O）could be formed and become an armoring precipitate layer on the BOFS surface, hindering the release of Fe2＋and the removal of Cr（VI）. Finally, the main mechanism of Cr（VI） removal by BOFS was described using several consecutive reaction steps.

关键词： Hexavalent chromium Basic oxygen furnace slag Fe2＋ Redox process Kinetics

Effect of melt current on multi-physical field and heat flow distribution during ESR process based on model of dynamic formation of slag skin

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2023年第6期30卷 1258-1267页

作者： Fu-bin Liu Xin-hao Yu Hua-bing Li Zhou-hua Jiang Hong-chun Zhu Xin Geng School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

A numerical model coupled with a multi-physical field based on dynamic formation of slag skin is established.After validation by comparing the experimental and simulation results of depth of metal pool,slag skin thickness and melt rate,it is utilized to investigate the effect of melt current on the coupled multi-physical field,slag skin thickness,metal pool depth and the heat flow distribution during electroslag remelting(ESR)Inconel 625 solidification process.The results showed that with the increase in the melt current,the velocities of ESR system and the temperature of metal pool increased,whereas the highest temperature of slag bath firstly decreased and then increased.With the increase in the melt current,the slag skin thickness,metal pool depth and melt rate increased.Furthermore,the characteristics of the heat flow distribution and the effect of melt current on the heat flow distribution were analysed.

关键词： Electroslag remelting Melt current Slag skin Model Multi-physical field

Modeling of flow and temperature distribution in electroslag remelting withdrawal process for fabricating large-scale slab ingots

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2017年第6期24卷 569-578页

作者： Wan-ming Li Zhou-hua Jiang Xi-min Zang Xin Deng school of Material and metallurgy University of Science and Technology Liaoning School of Metallurgy Northeastern University

Currently, the market demands for large-scale and high-quality slab ingots are increasing significantly. A novel electroslag remelting withdrawal （ESRW） process with two series-connected electrodes and a T- shaped mould was developed to produce large-scale and high-quality slab ingots. It is very difficult to ob- tain large slab ingots with good surface quality and high width-to-thickness ratio. And it is not efficient for improving the quality of slab ingots by using trial-and-error-based approaches because the ESRW mecha- nisms are very complex. Thus, a three-dimensional mathematical model was developed to determine the relationship between process parameters and physical phenomena during the ESRW process. The relation- ship between the temperature field of the ESRW process and the surface quality of slab ingots was estab- lished. A good agreement between the simulated and measured temperature fields of slab ingots was ob- tained. The results indicate that the maximum values of current density, electromagnetic force and Joule heat all occur at the electrode-slag interface between the two electrodes. It can be found that the flow is turbulent and the temperature distribution is uniform in the slag pool with the influences of buoyancy and electromagnetic force. The wrinkles in the narrow faces of slab ingots are caused by the relatively lower in- put power. Increasing the electrode width and reducing the curvature can significantly improve the surface quality of slab ingots.

关键词： Electroslag remeltingwithdrawal processLarge-scale slabSurface qualityWrinkleFlowTemperature field

在线全文

学校读者我要写书评

暂无评论

一步氨法净化铝电解烟气中氟盐的分离和转化

Journal of Central South University 2023年第1期30卷 108-120页

作者：李雪珂刘燕李小龙张廷安 Key Laboratory of Ecological metallurgy of Multi-metal Intergrown Ores of Ministry of Education School of MetallurgyNortheastern UniversityShenyang 110819China

铝电解烟气中含有氟化物、二氧化硫和二氧化碳等多种污染物,对环境和人类都有危害。目前,对于铝电解烟气净化技术的研究未涉及碳资源的回收,为了解决这个问题,本文提出了一种铝电解烟气一步净化技术。它是一种实现氟化物、SO_(2)和CO_(2... 详细信息

铝电解烟气中含有氟化物、二氧化硫和二氧化碳等多种污染物,对环境和人类都有危害。目前,对于铝电解烟气净化技术的研究未涉及碳资源的回收,为了解决这个问题,本文提出了一种铝电解烟气一步净化技术。它是一种实现氟化物、SO_(2)和CO_(2)的净化并将废气污染物转化为冰晶石和复合氨肥资源转化的技术,将铝电解烟气经一步氨法净化后的含氟化铵吸收液,通过加入氢氧化钠和氢氧化铝进行化学沉淀生成冰晶石。通过使用氟离子电极、XRD和SEM等分析和检测,获得了最佳操作参数:温度为70℃、搅拌速度为400 r/min、反应物浓度为0.5 mol/L、α_(k)(NaOH与Al(OH)_(3)的分子比)为3.1。

关键词：铝电解烟气冰晶石氟化铵一步氨法氟盐的转化

Solubility of RE_2O_3(RE=La and Nd) in light rare earth fluoride molten salts

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2018年第7期36卷 765-771页

作者： Xiaoping Zhu Shuchen Sun Chuan Liu Ganfeng Tu School of Metallurgy Northeastern University

The chemical reaction and dissolution processes of RE2 O3 in REF3-LiF（RE = La and Nd） molten salts were studied by X-ray diffraction, differential thermal analysis and chemical analysis. Firstly, RE2 O3 disperses in molten salts and reacts with REF3 and LiF, which lead to the generation of a new phase REOF, resulting in the dissociation or formation of complex ions by part of REOF, and the sedimentation of excessive REOF at the bottom. The RE contents in molten salts were used to determine the solubility of RE2 O3. The results show that with 20 mol%-40 mol% of REF3, the solubility ranges from 1.79 to 3.05 g RE2 O3 per100 g electrolyte and the corresponding mole concentration is 0.33%-0.87%. RE2 O3 solubility increases with increasing temperature and REF3 concentration. The natural logarithm of the RE2 O3 solubility is plotted against 1/T and can be interpreted by linear relationship. The fitting parameters can be used to estimate the solubility of RE2 O3 with minimized experimental efforts and difficult experiment conditions.

关键词： REF3-LiF RE2O3 Rare earth Molten salts Solubility Electrolyte

Comparison of the effects of Ti-and Si-containing minerals on goethite transformation in the Bayer digestion of goethitic bauxite

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,metallurgy and Materials 2023年第9期30卷 1705-1715页

作者： Guotao Zhou Yilin Wang Tiangui Qi Qiusheng Zhou Guihua Liu Zhihong Peng Xiaobin Li School of Metallurgy and Environment Central South UniversityChangsha 410083China

Goethitic bauxite is a widely used raw material in the alumina industry.It is an essential prerequisite to clarify the effect of Ti-and Si-containing minerals on goethite transformation in the Bayer digestion process,which could efficiently utilize the Fe-and Al-containing minerals present in goethitic bauxite.In this work,the interactions between anatase or kaolinite with goethite during various Bayer digestion processes were investigated using X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),transmission electron microscopy (TEM),and scanning electron microscopy (SEM).The results showed that anatase and kaolinite hindered the transformation of goethite.Anatase exerted more significant effects than kaolinite due to the dense sodium titanate layer on the goethite surface after reacting with the sodium aluminate solution.Adding the reductant hydrazine hydrate could eliminate the retarding effect by inducing the transformation of goethite into magnetite.In this process,titanium was embedded into the magnetite lattice to form Ti-containing magnetite.Furthermore,the weakening of the interaction between magnetite and sodium aluminosilicate hydrate reduced the influence of kaolinite.As a validation of the above results,the reductive Bayer method resulted in the transformation of goethite into goethitic bauxite with 98.87% relative alumina digestion rate.The obtained red mud with 72.99wt% Fe2O3could be further utilized in the steel industry.This work provides a clear understanding of the transformative effects of Ti-and Si-containing minerals on iron mineral transformation and aids the comprehensive use of iron and aluminum in goethitic bauxite subjected to the reductive Bayer method.

关键词： goethite magnetite kaolinite anatase Bayer digestion