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.     

镍火法熔炼技术发展综述

综述现在世界广泛应用的镍熔炼火法技术,如矿热电炉、反射炉、闪速炉、鼓风炉、转炉和奥斯麦特炉及其在我国的实际应用情况.     

铝合金熔铸用熔炼炉+保温炉炉组与熔保一体炉的优缺点比较

铝合金熔炼与精炼用炉主要有熔炼炉+保温炉炉组和熔保一体炉两种形式。与熔炼炉+保温炉炉组相比,熔保一体炉的建设费用和吨铝能耗低,但熔体质量差,所以对于品质要求高的铝合金熔铸产品可采用熔炼炉+保温炉组生产,对于品质要求低的铝合金熔铸产品可以采用熔保一体炉生产。而且无论是用熔炼炉+保温炉组还是熔保一体炉,当利用电解铝液直接配料生产铝合金熔铸产品时,都应对电解铝液进行除碱处理。     

陶瓷纤维模块在工业炉中的应用

以冷轧带钢退火炉为例,介绍了陶瓷纤维模块炉内衬的应用以及安装方法,并对模块化内衬和层铺毯式内衬的炉壁温度进行对比分析.结果表明,陶瓷纤维模块用于炉内衬显示了众多的优越性.在新型炉窑设计或旧炉窑的改造中,陶瓷纤维模块应该成为首选的设计方案.     

宝钢3号高炉的生产及炉型设计

对宝钢3号高炉炉体设计的过程以及炉型与操作制度相适应的过程进行了总结分析。认为这个过程可分为三个阶段:炉型演变期、操作炉型稳定期和炉型维护阶段。厚壁高炉投产初期,炉型存在巨大演变,操作制度难于适应;当操作炉型合理化之后,高炉具备了良好的操控性能和薄壁高炉的特征,炉型与操作制度相匹配,获得了良好的操作指标;高炉经历了10年的生产,进入炉型维护阶段,生产采取了有效的维护措施,使3号高炉仍具有良好的活力,保持良好的指标。     

大型高炉操作炉型合理性的特点及调整

从太钢5号高炉近年来对合理操作炉型的认识和调整过程出发,通过分析一定操作炉型下炉况运行参数, 煤气流分布特点,炉体各段炉衬温度、热负荷分布和冷却水温差等表征操作炉型的参数,以此来描述合理操作炉型 下的炉况特点。并以此为基础分析和探讨,大型高炉实现合理操作炉型的措施。     

唐钢高炉氯元素的平衡

 氯是高炉煤气管道系统腐蚀的根源,掌握氯元素在高炉内的分配去向可以为消除或抑制高炉煤气管道系统的腐蚀提供理论依据。通过数据采集和现场取样分析的方法对唐钢高炉氯元素平衡进行研究后发现：焦炭中的氯元素含量比含铁炉料高,但含铁炉料却是唐钢高炉氯元素负荷的最大来源,高炉冶炼过程中的氯元素绝大部分进入到高炉荒煤气,氯元素进入干法除尘高炉和湿法除尘高炉的分配去向存在比较大的差别,对于干法除尘高炉来说,炉顶煤气带走的氯元素是高炉氯元素负荷的最大支出;对于湿法除尘高炉来说,洗涤水带走的氯元素是高炉氯元素负荷的最大支出。     

融合大数据技术和工艺经验的高炉参数优化

 为了更精准地评判高炉运行情况,量化高炉指导方针。根据高炉生产过程的特点,应用大数据技术对高炉生产参数与铁水产量和高炉能耗等指标进行数据驱动分析,提出了一种优化高炉生产参数的新方法。首先,对某钢铁厂高炉各工序历史数据进行了采集、清洗、过滤和整合,建立了高炉数据仓库。然后,将多种聚类算法相结合,完成了对高炉炉况变化的详细划分。运用工艺经验与递归特征消除算法相结合,全面筛选得到能够反映炉况波动的强相关变量。应用统计学方法分析得出Class_a炉况对应的核心参数的最优范围,这对指导现场生产、保持高炉长期稳定顺行具有重要意义。     

攀钢4#高炉炉体破损与长寿化原因分析

介绍了攀钢4#高炉第一代炉役大修时的炉体破损情况以及炉底沉积物特点,分析了4#高炉一代炉役实现高效生产和长寿化的相关因素,对进一步认识钒钛矿高炉冶炼,强化高炉操作具有一定的指导意义。     

首钢京唐1号高炉操作炉型管理实践

从首钢京唐公司1号高炉近6年来操作炉型调整和变化过程出发,对比设计炉型,通过对原燃料管理、装料制度、送风制度、热制度、冷却制度和渣铁排放制度等高炉操作制度的摸索,分析总结高炉合理操作炉型特点,从而确定高炉操作炉型管理方案,使高炉煤气稳定,煤气形态合理,保持正常的操作炉型,确保高炉长期顺稳,实现高炉各项指标最优化。     

解决中天钢铁高炉炉壳上涨实践

 高炉炉壳上涨是近几年钢铁企业部分高炉面临的一个难题,控制高炉炉壳上涨对高炉的长寿、安全稳定运行有重要意义。针对中天高炉炉壳上涨问题,以压力容器盲板力的计算为依据,结合长期分析和治理实践,明确了高炉炉壳上涨的关键原因是由炉内压力产生的盲板力所导致;并给出了高炉炉壳上涨的5个具体步骤,炉底板变形,炉内耐材变形,耐材之间出现缝隙,有害金属沿着缝隙富集,炉壳逐步长高。在此基础上,针对性地研发了双炉底板结构,并在中天钢铁的多座高炉上进行了成功应用,解决了高炉炉壳上涨的难题。将探索高炉炉壳上涨原因的焦点从原料、操作、施工和耐材材质等方面转向高炉炉底板自身强度上。