Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.     

Evaluation of D113 cation exchange resin for the removal of Eu(Ⅲ) from aqueous solution

Batch adsorption experiments were conducted for the adsorption of Eu(Ⅲ) ions from aqueous solution by D113 resin. The results indicated that D113 resin could adsorb Eu(Ⅲ) ion effectively from aqueous solution. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.50 to 7.00 and the optimal adsorption condition was in HAc-NaAc medium with pH value of 6.50. The maximum uptake capacity of Eu(Ⅲ) ions was 290.9 mg/g D113 at 298 K, at an initial pH value of 6.50. The overall adsorption process was best described by Lagergren-first-order kinetics. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The thermodynamic parameters such as free energy (G) which were all negative, indicated that the adsorption of Eu(Ⅲ) ions onto D113 resin was spontaneous and the positive value of enthalpy (H) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Furthermore, Eu(Ⅲ) could be eluted by using 3.0 mol/L HCl solution and the D113 resin could be regenerated and reused.     

Phase structure and temperature dependent luminescence properties of Sr2LiSiO4F: Eu2+ and Sr2MgSi2O7: Eu2+ phosphors

Green-emitting Sr2LiSiO4F:Eu2+ and blue-emitting Sr2MgSi2O7:Eu2+ phosphors were synthesized by the conventional high temperature solid-state route,respectively.Their structures and photoluminescenee properties were comparatively investigated.It was found that the mixture phases of Sr2MgSi2O7 and SrF2 were obtained when a part of Sr2+ in Sr2LiSiO4F was replaced by some amount of Mg2+ in order to design the possible SrMgLiSiO4F:Eu2+ phosphor.Based on the photoluminescence analysis,Sr2LiSiO4F:Eu2+ phosphor exhibited a green broad emission band of main peak at 513 nm under the excitation of 365 nm,while the Sr2MgSi2O7:Eu2+ and SrMgLiSiO4F:Eu2+ phosphor showed blue emission centered at 467 nm.The temperature dependent photoluminescence properties and room temperature decay time for the three kinds of phosphors were also discussed in this paper.     

Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.     

EXAFS investigation and luminescent properties of nanosized Tb: Lu2O3 phosphors

Nanosized terbium doped Lu2O3 phosphors were synthesized via a modified co-precipitation processing.The as-prepared Tb:Lu2O3 phosphors was consisted of well crystallized nanosized sphere particles with a diameter of about 30 nnx Local structure of Tb ions in Lu2O3 lattice was investigated by an analytical approach based on Fourier transformation of the extended X-ray absorption fine structure(EXAFS) data.X-ray near edge structure (XANES) spectra suggested that all Tb ions doped were tervalonce.EXAFS results indicated that Tb ions have entered the Lu2O3 cubic lattice by means of solid solution.The coordination number and first shell Tb-O distance dropped with the increasing of Tb concentration.Emission spectra of the phosphors was shown to be typical for Tb3+ with main components at 542,550 and 490 nm,derived from irradiative relaxation of 5D4 level.The emission intensity decreased severely with the increasing of Tb concentration from 1 mol.% to 15 tool.%,suggesting a significant concentration quenching above 1 mol.% Tb.The reduction of emission intensity was interpreted by higher distortion derived relaxation among the surface state resident Tb3+ ions.     

Multi-Pass Simulation of Heavy Plate Rolling Including Intermediate Forced Cooling

Thermomechanical Controlled Processing (TMCP) including accelerated cooling after the final hot rolling pass is a well-established technology,widely applied in HSLA steel plate production.However,there are still certain limitations,especially for thicker plate.The rolling schedule includes a long holding period (HP) after the roughing stage to allow the temperature to fall sufficiently for optimised TMCP during finishing.Intermediate Forced Cooling (IFC) applied during the HP can increase productivity by decreasing the required hold time,can restrict austenite grain growth,and can also improve the subsequent strain penetration in thick plate with further metallurgical benefits.Multi-pass plane strain compression (PSC) tests have been performed on the thermomechanical compression (TMC) machine at Sheffield University including different severities of IFC.Clearly it is impossible to simulate all aspects of the temperature and strain gradients present in thick plates in laboratory specimens,and most of the tests were conducted at temperatures and strains calculated by Finite Element modelling as relevant to specific positions through the plate thickness.However,some aspects of the gradients were addressed with tests using cold platens.The results have indeed shown that IFC can shorten the HP and reduce austenite grain growth and its variation across thick plate.     

Overview of Particles and Bubbles in Continuously Cast Steel

This paper gives an overview of phenomena associated with particles and bubbles in continuously cast steel. During steel processing from deoxidation to solidification the inclusion population undergoes changes with opportunities of removal. Flotation is an important separation mechanism. Inclusion particles may accumulate in the solidifying strand, thus forming enriched bands, which depend on the type of casting machine. Bubbles are created during inert gas injection. They also change in size, can float out, but also form accumulation bands. The interaction of bubbles and particles is discussed. Internal structure that recently has been observed on the inner surface of bubbles will be reviewed.     

烦恼 快乐 艺术——池莉“人生三部曲”解读

池莉的"人生三部曲"--<烦恼人生>、<不谈爱情>、<太阳出世>诉尽了普普通通的市民烦恼,小说中主人公被柴米油盐、吃喝拉撒、老婆孩子等琐事所烦着,从而构成他们的"烦恼人生".然而池莉通过自己的艺术创作,以积极的人生态度,又让读者体会到生活本身的快乐,"烦恼人生"中包含着"快乐人生".     

属性块在工程图形中的研究与应用

介绍了在工程图形中用属性块标注表面粗糙度的方法.采用属性块不仅能避免大量重复性的工作,还能节省大量的存储空间,具有提高绘图速度、质量,便于修改,资源共享等应用价值.     

矿用减速机轴承座孔磨损修复技术

通过对可赛新耐磨修补剂性能的分析，提出利用可赛新耐磨修补剂解决某矿山1#ZL130减速机轴承座孔严重磨损修复的技术方案，通过修复实施，已修复的减速机运转正常，效果明显。     

提高钼铁生产指标的实践探索

分析了钼焙砂品位与铝耗之间的关系，指出钼焙砂品位是影响铝耗的主要因素；介绍了用铁矿粉代替铁鳞的可行性与必要性，进口矿与国内矿合理搭配使用，以及ＭｏＯ２６对提高冶炼回收率的益处。     

羰基镍粉末悬浮液性能研究

湿法成型在降低粉体团聚、改善素坯显微结构均匀性方面有着明显的优势。本工作采用乙醇为溶剂 ,PVB为分散剂和粘结剂 ,对以固相含量为 55% (质量分数 )的羰基镍粉悬浮液的制备和性能进行了研究。包括 :通过测定悬浮液的黏度和最终沉降体积确定最佳分散剂含量 ;含有粘结剂的悬浮液分两个阶段制备 :第一阶段悬浮液由羰基镍粉、乙醇和 0 2 % (质量分数 )PVB(分散剂 )组成 ,球磨 2 4h ,目的是打开颗粒团聚体和润湿粉料 ;第二阶段主要致力于悬浮液与粘结剂的混合 ,分别加入不同量的PVB ,球磨 2 4h。结果表明 ,分散剂含量为 0 2 %(质量分数 ) (相对于粉体 )时能使羰基镍粉末得到良好的分散。当粘结剂含量少于 6 % (质量分数 )时 ,在涂层坯体过程中容易出现裂纹 ,而粘结剂含量高于 6 %(质量分数 )时 ,悬浮液中含有较多的气泡。含 0 2 % (质量分数 )分散剂 ,6 % (质量分数 )粘结剂时可获得黏度适中 ,能够稳定悬浮的羰基镍粉悬浮液     

广钢转炉脱硫能力分析

对广钢转炉冶炼过程终点硫的控制能力进行了分析,指出转炉脱硫对转炉消耗指标的影响,提出了减轻转炉脱硫压力的措施。     

金刚石表面金属化提高 金刚石制品性能的研究

采用金属Ni粉,应用物理化学冶金方法,使金刚石表面金属化,然后按粉末冶金工艺制得金刚石的金属制品。利用JCXA-733型电子探针显微分析仪,分析金刚石表面金属化的某些物理特性,研究了金刚石金属制品的断口形貌,以及金刚石与金属胎体间的微观组织结构和成分。阐述了金刚石表面金属化对金刚石颗粒与金属胎体间的强化机理,从而提高金刚石工具水平。     

二元铁酸钙还原行为的研究

实验在合成CF2，CF、C2F的基础上，利用热台显微镜动态地观察了二元铁酸钙还原过程中的显微结构变化，考察了它们的还原性，还原前后的强度变化，结果表明C2F，CF．CF2还原性依次增强；CF2的抗压强度在还原度较低时有明显的下降，在还原度较高时随还原度的增加抗压强度增加；CF与C2F的抗压强度随还原度的提高而提高；CF2在还原过程中有明显的裂纹产生，裂纹的产生影响了CF2的强度。     

网络计划技术在钼丝技改安装工程中的应用

阐述了钼丝技改安装工程中应用网络计划技术，合理安排最早开工时间，有效利用最早开工时间差，加强关键路线安装，不断调整安装时间计划，解决设备安装与土建施工交叉作业的矛盾、主体工程与辅助工程安装的矛盾、安装作业与正常生产矛盾等问题，取得了时间、人力、物力资源的最优化利用，提高工效的目的，实现了工程管理的预定目标。     

前驱粉团聚度对钼粉及后期制品性能的影响

通过不同团聚度前驱粉钼酸铵在制粉、压型、烧结以及拉拔工艺过程中存在的差异进行了对比分析，结果表明前驱粉的团聚度对钼金属材料制备的各个环节都有影响，且随着团聚度的提高，影响程度提高。同时，对粉体团聚的机理进行了分析，提出了消除团聚的意见和建议，指出非团聚前驱粉的研究和工业应用对提高钼金属材料性能具有重要意义。     

两种金属陶瓷的氧化行为

通过热天平的重量/温度曲线、氧化腐蚀动力(k-t)曲线和增重-时间(Δw-t)曲线,比较Mo-ZrO₂型和Cr-Al₂O₃型金属陶瓷的氧化行为。实验结果表明:在大气中温度为700℃时经过70分钟后,其增重前者是后者的16倍左右。     

空气消耗系数对钢坯铁皮除净率的影响

本文针对某钢1#加热炉钢坯除鳞效果差的问题，对比分析了相同参数的2#炉在热工制度上的差异。在忽略仪表计量误差、阀门开口度误差等情况下，采取了提高1#加热炉均热段空气消耗系数的方法。并分析提出了既不增加脱碳层深度又能使与基体粘结紧密的FeO转化成易脱落的Fe2O3或Fe3O4的空气消耗系数范围。批量生产工艺表明，改善后的热工制度达到了将1#加热炉钢坯氧化铁皮完全除净的目的。