电极/碱性聚电解质界面的微分电容曲线和零电荷电位测定

碱性聚合物电解质作为现代碱性氢氧燃料电池的核心组成部分,其单离子导体的特性使得“电极/碱性聚电解质”界面的性质与“电极/溶液”界面有所不同。本文使用微电极,运用循环伏安、电化学交流阻抗以及浸入法等方法,测定了电极/碱性聚电解质界面的微分电容曲线和零电荷电位。该界面的微分电容曲线呈“U”状,且存在局域极小值,该极小值所对应的电位与浸入法测得的零电荷电位数值一致。单离子导体的特性使得“电极/碱性聚电解质”界面在零电荷电位两侧表现出不同的电化学极化行为。

高密度互连印制电路板孔金属化研究和进展

孔金属化互连是印制电路板(PCB)高密度集成的核心制程之一,化学镀铜和电子电镀铜是实现孔金属化的关键技术。本文介绍HDI-PCB的概念和制作流程;综述化学镀铜和电子电镀铜孔金属化互连的研究和进展,包括溶液组成和操作条件的影响,添加剂及其相互作用机理,以及盲孔填充和通孔孔壁加厚机制;展望高密度互连印制电路板电子电镀基础研究及新技术发展方向。

亚硫酸盐无氰电沉积金新工艺及机制(英文)

直接以氯金酸作为主盐、羟基乙叉二膦酸(HEDP)作为镀液稳定剂和镀层细化剂、结合添加剂,组成亚硫酸盐无氰镀金新工艺;研究镀液稳定性、镀层形态及金电沉积机制。结果表明,HEDP可明显提升镀液稳定性;不含HEDP的亚硫酸盐镀金液中,镀层呈棒状晶粒并随沉积时间延长而逐渐生长,导致镀层外观随镀层厚度增加由金黄色转变为红棕色。镀液含有HEDP时,金晶粒形态由棒状转变为棱锥状,且棱锥状晶粒随沉积时间延长生长速率较小,镀层厚度为1μm时仍呈现金外观。电化学实验表明金电沉积不经历成核过程。

An online BOF terminal temperature control model based on big data learning

The development of basic oxygen furnace(BOF)intelligent steelmaking model based on artificial intelligence and big data is the focus of international research and development.In the view of the current situation that the BOF cannot continuously detect the composition and molten steel temperature,combined with the monitoring results of the high-definition and high-brightness camera at the converter mouth,an online BOF terminal temperature control model is established based on big data learning case-based reasoning model and expert system model.The on-site online operation shows that the model can effectively improve the"flying lance"phenomenon and the splashing condition,the stability and safety of smelting process are better than that of artificial smelting,the"flying lance"rate decreases from 39.2% to 0,the early splashing rate decreases from 21.4% to 13.3% and the late splashing rate decreases from 81.25% to 56.7%.When the temperature fluctuation is controlled at±15 oC,the hit rate of the terminal temperature under the automatic control of the model is 90.91%.

Evolution of inclusion and microstructure in Ti-Zr deoxidized steel during hot compression

The effects of different hot deformation amounts on the evolution of inclusion and microstructure in Ti-Zr deoxidized steel were studied by utilizing the Thermecmaster-Z hot simulation test machine,automatic scanning electron microscope equipped with energy-dispersive spectrometer,and electron backscattered diffraction.The results indicated that hot deformation amount has no significant effect on the number density of oxide,but the MnS that precipitated on the Ti-Zr oxide surface undergoes extension and breakage,resulting in the changes in oxide aspect ratio.Moreover,the fracture of nitride mainly occurs in the sample with the second pass deformation amount of 42.9%and 71.4%,and the degree of fragmentation of nitride is more serious with the deformation amount increasing.During the hot compression,sulfide undergoes breakage and extension,and with the second pass deformation amount increasing,the breakage and extension of sulfide present a periodic change.Finally,with the increase in hot compression amount,the ferrite types in microstructure change from acicular ferrite and bainitic ferrite to polygonal ferrite,and the ferrite grain size is refined.When the total deformation amount increases from 30%to 80%,the ferrite grain sizes of grain boundary with the misorientation of 4°and 15°decrease from 4.14 and 5.67μm to 3.47 and 4.40μm,respectively.However,when the total deformation amount increases to 80%,the harmful ferrite/pearlite banded structure appears in the micro structure.Refining ferrite grain size and avoiding harmful microstructure are the key for the optimization of hot compression process.

Banded structure control of low carbon microalloyed steel based on oxide metallurgy

Banded structure is a common harmful microstructure for low carbon microalloyed steel,which seriously shortens the service life of processed parts.In order to study the effect of oxide metallurgy on improving banded structure,the Ti-Zr deoxidized low carbon microalloyed steel that can play the oxide metallurgical role of inclusion was chosen as the research object,and the inclusion characteristics,microstructure and transverse and longitudinal mechanical properties after hot rolling were analyzed.The results showed the inclusion number density increased in all experimental steels after hot rolling,and a large number of long strip inclusions with aspect ratio greater than 3 appeared along the rolling direction.In addition,after hot rolling,there were element segregation bands in the experimental steels,and granular bainite bands were formed in the element enrichment zone.However,the intragranular ferrite generated in the cooling process destroyed the continuity of granular bainite bands,so that the microstructure anisotropy indexes of experimental steels were small.The mechanical properties analysis showed that the anisotropy of performance was mainly reflected in plasticity and toughness in the experimental steels.Among them,the difference ratio of elongation,section shrinkage and impact energy of No.2 steel was 1.69%,3.87% and 1.69%,respectively,which were less than those of No.1 steel and No.3 steel.The anisotropy of microstructure and mechanical properties of No.2 steel that full played the role of oxide metallurgy were improved,and the banded structure control of low carbon microalloyed steel can be realized by oxide metallurgy technology.

Model for RuhrstahI-Heraeus （RH） decarburization process

A mathematical model was established to predict the carbon content of ultralow carbon steel in the Ruhrstahl-Heraeus （RH） process. The model was solved using the fourth-order Runge-Kutta method and assumed that the volume of steel partaking in the reaction depends on the decarburization mechanism. After analyzing the decarburization process using the proposed model, the following conclusions were drawn. First, the initial carbon and oxygen contents in the RH degasser should be stabilized in the range of （200-350） × 10^-6 and （500-700） × 10^-6, respectively. Second, in the initial stage, the pressure should be reduced as quickly as possible. Third, oxygen blowing should begin as early as possible when the forced decarburization is needed and the minimum oxygen flow rate should be 0.1923 m3/（t rain）. Finally, expanding the diameter of the snorkel tube from 480 to 600 mm clearly enhances the decarburization rate.

Effects of yttrium and zirconium additions on inclusions and mechanical properties of a reduced activation ferritic/martensitic steel

The effects of two alloying elements,i.e.,yttrium(Y)and zirconium(Zr),on the inclusion,microstructure,tensile property and impact toughness of reduced activation ferritic/martensitic(RAFM)steel are analyzed.The size and number of particles were determined by optical microscopy,and the particle types were examined by scanning electron microscopy.The size of?20% and?85% of the inclusions lied in the range of 0.5-1.0μm and 0.5-3.0μm,respectively.In Y-and Y-Zr-containing specimens,the density of the fine inclusions,with a size less than 0.5μm,was found to be 1.06×10^17 and 9.82×10^16 m^-3.respectively.All specimens were normalized at 1323 K for 30 min and tempered at 923 and 1023 K for 90 min,resulting in the formation of tempered martensite with M23C6 carbides and MX precipitates.Zr-containing RAFM steel tempered at 923 K formed M23C6 carbides and nano-sized carbides with Zr,conferring superior strength balance and impact toughness.The yield strength of alloy reached 695 MPa,and a low ductile-brittle transition temperature of 238 K was maintained.

Review on development of reduced activated ferritic/martensitic steel for fusion reactor

Materials are stil one of the main technical bottlenecks restricting the development of fusion reactors.Reduced activated ferritic/martensitic steel(RAFM)is considered one of the main candidate structural materials for fusion reactor cladding due to its good radiation resistance and mechanical properties.In the past 40 years,RAFM steel has made considerable progress,but numerous problems remain to be solved.The improvements in RAFM steel in recent years,such as chemical composition optimization,clean preparation technology,radiation performance,and applicable welding technology,were systematically summarized.A systematic review of new RAFM steels was conducted,the development direction of the traditional smelting process was analyzed,and the application of laser additive manufacturing technology to RAFM steel was introduced.The effect of rradiation on the microstructure and mechanical properties of RAFM steel was described,and welding methods of RAFM steel and their research progress were reviewed.Finally,the potential applications of Si,Ti,and Zr in improving the performance of RAFM steel,electroslag remelting technology in clean smelting,heat treatment process in optimizing radiation performance,and laser-beam welding in RAFM welding were prospected and summarized.

Effect of zirconium on inclusions and mechanical properties of China low activation martensitic steel

The effects of 0.01–0.11 wt.%Zr on the inclusions,microstructure,tensile properties,and impact toughness of the China low activation martensitic steel were investigated.Results showed that Zr exhibits good deoxidation and desulfurization abilities.The scanning electron microscope was used to examine the inclusions in the ingots.The main inclusions in the alloys were Zr–Ta–O,Zr–O,and Zr–O–S.However,some blocky Zr-rich inclusions appeared in Zr-2 and Zr-3 alloys.Typical martensitic structures were observed in the alloys,and average prior austenite grain sizes of 21.1,15.7,and 14.8µm were obtained for Zr-1,Zr-2,and Zr-3 steels,respectively.However,increasing Zr content of the steels deteriorated their mechanical property,owing to the blocky inclusions.The alloy with 0.01%Zr resulted in excellent mechanical properties due to the fine inclusions and the precipitation of Zr3V3C carbides.Values of 576 and 682 MPa were obtained for the yield strength and ultimate tensile strength of Zr-1 alloy,respectively.Furthermore,the ductile–brittle transition temperature of the alloy decreased to−85℃.

Chromium Recycling from Argon-oxygen Decarburization Dust in Hot Metal Pre-dephosphorization Process

The chromium recycling from the stainless steel dust of an argon-oxygen decarburization （AOD） furnace during a hot metal pretreatment process was investigated. Experiments at different temperatures or with different amounts of AOD dusts were carried out in a laboratory furnace equipped with MoSi2 heating elements and subsequently industrial experiments were conducted in a stainless steelmaking factory, in order to study the thermodynamic mechanism of C and Si reacted with Cr2O3 to get Cr from AOD dust. The results showed that the reaction between C and Cr2 O1 occurred below 1572.18 K. Although its reducing ability was weaker than that of Si, C enabled the Cr in Cr2O3 in the AOD dust to be recycled using the Si in the slag. By combining the AOD dust added in an earlier stage, the hot metal pretreatment slag added in a later stage could not only recycle Cr from AOD dust but also remove Si, S, and P. Higher hot metal temperatures resulted in higher Cr content and lower remained P concentration in the molten iron.