高炉风口上超音速火焰喷涂金属-陶瓷梯度层的可行性

在高炉风口表面制备一层适宜的金属-陶瓷梯度热障涂层,是提高风口寿命的一种有效的方法.本文旨在验证在风口上制备金属-陶瓷梯度保护层,提高高炉风口寿命的可行性.通过大型的有限元仿真软件AN-SYS,模拟分析了在紫铜表面喷涂陶瓷热障层的隔热效果,并且探讨了HVOF涂层的性能.结果发现,仅仅0.4 mm厚的ZrO2涂层就可以使铜基体温降200℃左右,而且超音速火焰喷涂打底的金属-陶瓷涂层的抗氧化性、热震性优于其他喷涂方法,这表示能够从材料和工艺两方面解决风口喷涂陶瓷层易脱落的问题.证明了在风口上喷涂金属-陶瓷梯度热障涂层的可行性以及利用HVOF打底层制备金属-陶瓷热障层的优势.     

高炉风口用铜基体防护涂层的制备、微结构和性能研究

为了延长高炉风口的有效服役寿命,以纯铜板为基材,NH₄Cl为催渗剂,以镍、铁、铝为共渗剂的主要成分,采用包埋共渗法在纯铜基体表面制备了防护涂层。研究了催渗剂含量、共渗剂配比、保温时间对防护涂层及涂层/基体界面结构的影响。利用XRD、SEM、EDS对所制备的涂层物相组成与显微结构进行了表征,并评价了涂层的显微维氏硬度。结果表明：通过调节催渗剂NH₄Cl的含量和共渗剂Ni∶Fe∶Al的比例,经热处理后可制备出与纯铜基体呈冶金结合的涂层。铝元素渗入到铜基体后,形成的渗层具有明显的渐变结构,使材料的显微维氏硬度明显提高。渗层中“高铝相”的存在阻碍了铜基体的位错运动,进一步提高了材料的显微硬度。     

高炉风口套的损坏形式及原因分析

风口套是高炉鼓风系统的重要组成部分，风口套出现裂纹、烧损或被煤粉磨漏，不仅影响高炉稳定顺行，而且还会威胁到炉前生产安全。本文就高炉风口套的损坏形式及其产生的原因展开讨论。     

涂层基体条件对梯度涂层残余应力影响研究

采用有限元法，对结构一定的Al/Ni-ZrO2梯度涂层在基体条件改变时涂层的残余应力进行了分析，结果表明，基体材料的热膨胀系数对涂层的残余应力有显著的影响，对于基体为圆柱形的涂层，其基体与涂层界面的残余应力梯度，最大轴向拉应力均随热膨胀系数的增大而线性增大，表面纯陶瓷层与次层界面残余应力梯度则随之减小，增大基体的直径和厚度，可缓和涂层残余应力，并在基体直径为36mm,厚度为20mm时各残余应力基本稳定。     

梯度过渡涂层的制备

本文采用多靶磁控溅射技术制备ＴｉＣ／Ａｌ界面梯度过渡层，过渡层由ＴｉＣ和Ａｌ的成分梯度变化组成，其成分由Ａｌ基体侧平缓过渡到ＴｉＣ涂层侧。梯度过渡层的成分变化经ＡＥＳ测定，并和光学金相显微镜观察了涂层形貌。实验结果表明，当梯度层厚主于某临界值后，由内应力所致的表层ＴｉＣ裂纹消除。     

高炉风口法兰工厂化预制安装技术

本文以某公司淘汰落后/异地技改项目工程为例,介绍了高炉风口法兰工厂化预制加工工艺、制作关键技术以及安装技术要点等。该技术具有安装精度高、可改善施工环境、减少高空作业、降低安全风险、加快施工进度、降低施工成本等特点,应用后经济效益显著,是一项值得推广的安装技术。     

Q235钢基体LZAS微晶玻璃/Y-TZP梯度涂层接触应力的数值模拟

运用有限元软件对Hertz接触状态下Q235钢基体LZAS微晶玻璃/Y-TZP梯度涂层的接触应力进行了分析。讨论了梯度层厚度、梯度层层数和物性参数渐变方式(3Y-TZP体积组分差)对涂层接触应力分布情况的影响。结果表明:涂层的径向接触应力和Mises应力的最大值位于接触中心处,最大剪切应力则位于涂层表层下方靠近接触中心处;涂层表面径向应力、整体最大Mises应力和涂层/基体界面剪应力与涂层的层数、厚度以及3Y-TZP体积组分差均有密切关系。     

1880m~3高炉风口回旋区特征的研究

随着新中国的成立,我国钢铁工业的发展十分迅速,现在已经成为我国国民经济的重要支柱产业,并成为世界生产的第一大国。钢铁生产的高炉内的一大重要反应区域就是高炉风口回旋区,回旋区的形成以及反应的情况,将对高炉上部炉料的均衡下降、下部煤气的分布以及整个高炉内的传质转热过程产生直接的影响。因此,本文通过对1880m3高炉风口回旋区的形成进行分析,进一步对其特征进行分析。     

梯度功能涂层的剥落现象分析与梯度分布的优化

梯度功能材料的优化设计, 可以转化为梯度分布函数的设计。采用幂函数来描述梯度分布, 使材料优化问题简化为该幂指数(称为梯度指数) 的优化。对梯度功能涂层-基底结构的剥落现象进行了分析, 推广了文献[ 9 ]的结果, 给出了在梯度功能涂层的基底中平行于界面稳态扩展的裂纹的能量释放率和应力强度因子的解析表达式, 并由此计算了最优的梯度分布指数。同时, 还讨论了梯度功能涂层耐高温抗氧化性能与热应力缓和之间的关系。      

Multivariate process monitoring of an experimental blast furnace

Process monitoring by use of multivariate projection methods has received increasing attention as it can reduce the monitoring problem for richly instrumented industrial processes with many correlated variables. This article discusses the monitoring and control of a continuously operating experimental blast furnace (EBF). A case study outlines the need for monitoring and control of the EBF and the use of principal components (PCs) to monitor the thermal state of the process. The case study addresses design, testing and online application of PC models for process monitoring. The results show how the monitoring problem can be reduced to following just a few PCs instead of many original variables. The case study highlights the problem of multivariate monitoring of a process with frequently shifting operating modes and process drifts and stresses the choice of a good reference data set of ‘normal’ process behavior. Possible solutions for adaptations of the multivariate models to process changes are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

含钛高炉渣催化剂的光催化活性

以攀钢含钛高炉废渣为原料,在不同温度下煅烧合成了钙钛矿型硫酸掺杂的含钛高炉渣催化剂(sulfuric acid-modified titanium-bearing blast furnace slag,STBBFS),研究了混晶结构和硫掺杂对含钛高炉渣光催化活性的影响,结果表明,含钛高炉渣催化剂具有钙钛矿/锐钛矿混晶结构,粉体的颗粒形状不规则,煅烧后粒径变大;在紫外区域具有很强的光吸收能力,STBBFS催化剂的光催化活性由Cr(Ⅵ)的还原率评价.煅烧温度为400℃时,STBBFS催化剂的表面存在含量较高的SO2-4和较高的CaTiO3/TiO2晶相比,具有较高的光催化活性,用500 W中压汞灯照射10 h,可将浓度为20 mg·L-1的六价铬废水完全降解.     

Interfacial and biological properties of the gradient coating on polyamide substrate for bone substitute

Fabrication of bioactive and mechanical matched bone substitutes is crucial for clinical application in bone defects repair. In this study, nano-hydroxyapatite/polyamide (nHA/PA) composite was coated on injection-moulded PA by a chemical corrosion and phase-inversion technique. The shear strength, gradient composition and pore structure of the bioactive coating were characterized. Osteoblast-like MG63 cells were cultured on pure PA and composite-coated PA samples. The cells'' adhesion, spread and proliferation were determined using MTT assay and microscopy. The results confirm that the samples with the nHA/PA composite coating have better cytocompatibility and have no negative effects on cells. To investigate the in vivo biocompatibility, both pure PA and composite-coated PA cylinders were implanted in the trochlea of rabbit femurs and studied histologically, and the bonding ability with bone were determined using push-out tests. The results show that composite-coated implants exhibit better biocompatibility and the shear strength of the composite-coated implants with host bone at 12 weeks can reach 3.49 ± 0.42 MPa, which is significantly higher than that of pure PA implants. These results indicate that composite-coated PA implants have excellent biocompatibility and bonding abilities with host bone and they have the potential to be applied in repair of bone defects.     

氧化钴/高炉渣催化剂的丙烷氧化脱氢性能

以攀钢高炉渣为载体,采用固体研磨法负载氧化钴,制备了氧化钴/高炉渣负载型催化剂,并以XRD、 H2-TPR技术对催化剂进行表征,研究了其对丙烷氧化脱氢制丙烯反应的催化性能.实验结果表明氧化钴负载在高炉渣上提高了丙烯选择性,氧化钴的负载量为20%时催化剂表现较好的催化性能,在550℃时丙烷转化率为28.80%,丙烯选择性为35.51%.本实验为资源综合利用及减少环境污染提供了新方法.     

陶瓷／金属梯度热障涂层的制备及性能评价

为了评价陶瓷／金属梯度热障涂层的性能，设计了4种涂层方案和2种基体材料（1Cr18Ni9Ti和2Cr13）．利用单枪单送粉器成功地制备了线性梯度涂层．通过观察涂层的微观结构、测量涂层的抗热震性能和热残余应力来评价涂层的性能．利用扫描电镜对各种陶瓷涂层的微观结构进行了观察和分析，利用X射线能谱分析得到了陶瓷梯度涂层试样中的不同区域的衍射图．热震试验表明，梯度涂层比非梯度涂层具有更好的抗热震性能．采用钻孔法对不同涂层方案进行了残余应力的测量，结果表明，压应力出现在1Cr18Ni9Ti基体材料上，而拉应力出现在2Cr13基体材料上．     

LIGGGHTS and EDEM application on charging system of ironmaking blast furnace

Chemical reactions between gas and raw material are determined by burden distribution, especially radial distribution of pellet/sinter and coke in blast furnace. An appropriate control of burden distribution is required to yield a smooth operation with effective performance and an appropriate gas flow at the wall. This paper studies two different DEM packages application for charing system of ironmaking blast furnace. The simulations (EDEM 2.2.1 and LIGGGHTS 3.4.0) based on the discrete element method (DEM), are validated using mass fraction distribution in the trajectory of pellet flow and burden distributions of pellet on a horizontal plane. The results show that good agreements are found among EDEM, experiment and LIGGGHTS. Furthermore, reducing shear modulus of material can increase calculation speed of DEM.     

梯度功能型金属氧化物涂层阳极(DSA)的制备

首次用梯度功能材料设计思想制成了成份呈梯度分布的金属氧化物涂层阳极（DSA）,比用传统方法制备的阳极寿命提高了40多倍,并用SEM、EDX对其界面过渡的形貌及成份分布进行了研究。     

A novel conversion of Ti-bearing blast furnace slag into Ti-containing zeolites: Comparison study between FAU and MFI type zeolites

In this work, the synthesis of FAU and MFI type Ti-containing zeolites from Ti-bearing blast furnace slag was first achieved via a facile hydrothermal method. The synthesized zeolites were identified to be Ti-NaX and Ti-NaZSM-5 zeolites, with excellent specific surface area of 663.2 and 325.2 m²/g, respectively. Ti species in the Ti-NaX zeolite contained the framework Ti species and amorphous extraframework Ti species, while the Ti species in Ti-NaZSM-5 zeolite were in the form of the two species of above and another anatase TiO_2. To investigate the potential application of the synthesized zeolites in photocatalysis field, an exploratory study was carried out by degradation of methyl orange under UV irradiation. As demonstrated, the Ti-NaZSM-5 zeolite showed higher photocatalytic performance and was more suitable to be the support of the TiO₂ photocatalyst than the Ti-NaX zeolite. Innovative conversion of TBFS into Ti-containing zeolite materials does provide not only a novel and low-cost approach to waste management, but also a promising material candidate for catalytic oxidation and environmental purification.     

Mix design of concrete for prestressed concrete sleepers using blast furnace slag and steel fibers

The application of ground granulated blast furnace slag (GGBFS) and steel fibers in prestressed concrete railway sleepers was investigated in this study. The use of GGBFS was considered as an eco-friendly material aimed at reducing CO₂ emissions and energy consumption as well as to enhance the durability performance of railway sleepers. Steel fibers improves the durability and structural performance in terms of crack control and reduction of spalling and can replace shear reinforcement. The mix proportions of the concrete incorporating GGBFS (56% GGBFS) and GGBFS with steel fibers (56% GGBFS and 0.75% steel fibers) were determined through a series laboratory tests and a life cycle assessment. These mixes satisfied the requirements of the Korean Railway Standard and resulted in improved flexural capacity as well as less CO₂ emissions compared with current railway sleepers. Using these mixes, a total of ninety prestressed concrete sleepers were produced in a factory under the same manufacturing process as current railway sleepers, and their mechanical properties as well as durability performance were evaluated. The mix with partial replacement of Type III Portland cement by GGBFS showed an improved resistance to chloride ion penetration and freeze-thaw cycles compared with the concrete used for current railway sleepers. However, these mixes were more vulnerable to carbonation. The mix with GGBFS and steel fibers (mix BSF) showed a slightly better durability performance than the mix with GGBFS only (mix BS), including better carbonation and freeze-thaw resistances. The mix BSF showed decreased chloride ion penetration depth than mix BS but showed a slightly higher chloride ion diffusion coefficient.