国内第一套热媒式高炉热风炉余热利用装置通过鉴定

本钢1号高炉热媒式热风炉余热利用装置于1985年12月通过鉴定,来自科研、设计、生产和设备制造等方面20多个单位的60余名代表出席了鉴定会议。该装置由北京钢铁设计研究总院设计,采用北京燕山石油化工公司研究院生产的YD-300导热油作热媒体,对热风炉燃烧用空气和煤气同时进行预热。系统投入运行调试至转入正常工作状态,经三个月工业性试验     

乙烯6号炉预热段翅片管腐蚀泄漏原因分析

对发生腐蚀穿孔的乙烯6＃炉预热段翅片管腐蚀穿孔的原因进行了分析,通过对腐蚀产物的能谱分析和金相组织分析,指出烧焦时烧焦空气窜入,引发FeS反复氧化燃烧剥落所致.是造成翅片管均匀腐蚀的主要原因.由于预热段炉管为水平安装,在裂解炉停工蒸汽吹扫过程中,残留的蒸汽冷凝成水汇集在炉管下部或凹陷处,进入炉内空气中的氧溶解在其中,从而形成了氧的腐蚀环境,使炉管因腐蚀形成的FeS保护膜遭到破坏,最终导致炉管下部穿孔.     

高压蒸汽锅炉炉管腐蚀分析及探讨

大庆石化公司两台辅助高压蒸汽锅炉,在检修时发现炉管壁厚减薄量较大,出现点腐蚀,经过腐蚀分析,得出造成炉管腐蚀的因素是多种腐蚀叠加起来的,由此提出了减少或避免炉管的损坏建议。     

焦化加热炉炉管腐蚀原因分析及对策

通过金相试验、扫描电镜、能谱分析以及X射线衍射分析对焦化加热炉炉管的高温腐蚀形貌、腐蚀物成分进行了分析。最终对焦化炉管的减薄原因进行了研究。结果表明,由于炉管向火面操作温度过高,且渣油、燃料和干气中含有腐蚀介质,1Cr5Mo钢管不但发生氧化腐蚀,还发生硫化腐蚀,导致炉管腐蚀加速,使炉管腐蚀减薄。     

高压锅炉水冷壁管失效分析

借助于光学显微镜和扫描电镜、电子能谱仪对高压汽包锅炉水冷壁管爆破口形貌、组织以及附着的腐蚀产物成分和化学状态进行研究．结果表明，炉水中存在过量游离NaOH和水冷壁管存在局部过热是造成炉管凿槽腐蚀的两个基本原因．提出了炉水中游离碱含量的精确算法并定量分析了一级除盐水电导率与其中游离NaOH含量之间的关系及其对炉水游离碱的影响．补给水品质不良是造成炉水中游离：NaOH过高的主要原因．要防止炉管碱腐蚀就必须保持锅炉受热面清洁，控制炉水游离碱含量，避免炉膛偏燃及火焰冲蚀，消除焊瘤及其它干扰炉水流动的因素．努力提高锅炉补给水品质，将其电导率控制在适当的标准以下尤为重要．     

卧式中频加热弯管机

一九七八年,我厂为仿制国外引进设备, 试制了醋酐裂化炉炉管。因炉管在高温、强腐蚀条件下工作,对弯曲后的几何尺寸和金相组织要求很严。我们通过技术攻关,自己设计制造了一台专用的卧式中频加热弯管机,用中频加热的方法把整根管材连续弯成螺旋管,使用     

乙烯裂解装置炉管焊缝腐蚀失效分析

针对发生失效的乙烯裂解装置炉管焊缝,采用材料化学成分分析、宏观形貌观察、金相检查、扫描电镜和能谱分析等手段进行了失效分析,同时测量了原料油的终馏点,模拟了含焊接缺陷的炉管内的流场。结果表明:焊缝腐蚀区存在大量硫及低熔点共晶物;失效炉管段的介质温度处于加氢尾油的终馏点附近;活性硫在镍基焊缝偏聚,镍与硫形成的低熔点共晶物在高温下熔化,并被介质冲走,导致炉管快速腐蚀。     

1#常压炉出口短节腐蚀分析与预防对策

对独山子炼油厂三蒸馏装置的1^#常压炉出口短节的腐蚀原因进行了分析，包括炉管材料化学成分分析，拔头原油硫含量，酸值分析和宏观检验。结合对短节选材，短节结构设计，短节焊接方式等的分析，认为由于短节选材不当，结构，焊接方式不合理，导致了此部位高温环烷酸腐蚀的发生与加剧。并结合分析结果，提出了控制环烷酸腐蚀的主要应选择耐环烷酸腐蚀的材料等措施。     

制氢转化炉炉管剩余寿命评估

通过对炼油厂制氢转化炉炉管试样的化学成分、显微组织、常温力学性能、高温力学性能、高温持久性能进行测定和分析,对炉管的安全状况进行了评估,并估算了炉管的剩余使用寿命。在考虑一定的安全系数后,预测出炉管的剩余寿命为6年。     

热水锅炉炉管腐蚀破坏事故分析

采用X射线衍射相分析技术对某热水锅炉炉管的腐蚀产物进行了分析，对炉管材质的化学成分，硬度，抗拉强度和显微组织分别进行了检测，并对锅炉给水的含氧量进行了测定，综合分析结果表明，造成锅炉炉管穿孔漏水的主要原因是氧腐蚀。     

FORMATION LAW OF PHASES IN ULTRAFINE POWDERS OF Al-Cu ALLOY PREPARED BY GAS EVAPORATION PROCESS

１ＩＮＴＲＯＤＵＣＴＩＯＮＵｌｔｒａｆｉｎｅｐｏｗｄｅｒｓｗｉｔｈａｐａｒｔｉｃｌｅｓｉｚｅｌｅｓｔｈａｎ１００ｎｍｈａｖｅｅｘｃｅｌｅｎｔｐｒｏｐｅｒｔｉｅｓｉｎｃｏｎｔｒａｓｔｔｏｃｏａｒｓｅｇｒａｉｎｍａｔｅｒｉａｌｓ［１,２］ａｎｄｈａｖｅｗ...     

Two decades of change in graduate education in metallurgy/materials—A perspective

It is now almost a decade since the introduction of massive federal support to universities for graduate education and research in the materials field. Accordingly, it is appropriate to examine the changes in the nature and activity of the field which have occurred during this period, both in the universities themselves, and in professional practice in industry and government, and also the implications of such changes for graduate education in metallurgy and materials science in the future.The present paper examines the growth of relevant university activities in the field over the past 10 years in comparison with that during the preceding decade and with the growth of engineering, science and advanced education in general in the United States, i.e., the question of the supply of new personnel with advanced training in the materials field. While it is appreciated that the nature and quality of education must be of prime importance, this paper deals principally with the numerical aspects of graduate education in materials, rather than with the philosophy, as a necessary first step in the broader study which is advocated.     

Changes in the vibrational energies and interatomic spacings upon the formation of vacancies in the volumes and in the cores of crystallite-conjugation regions of polycrystalline transition metals with cubic lattices

The changes in the vibrational energies and the signs of changes in the interatomic spacings upon the formation of vacancies in the bulk of metal and in the cores of the crystallite-conjugation regions (CCR) in polycrystalline transition metals with bcc and fcc lattices have been determined. The vibrational energy increases upon the formation of a vacancy in the bulk of metal because of a positive “relaxation” contribution to the change in the force constant of the atoms surrounding a vacancy. Positive “relaxation” contributions to the changes in the force constants and, correspondingly, an increase in the vibrational energy of the atoms surrounding a vacancy arise also upon the formation of “split” vacancies (S vacancies) in the cores of CCRs of polycrystalline transition metals with a face-centered cubic lattice. The positive “relaxation” contributions to the changes of the force constant of atoms in the region of localization of S vacancies are caused by a decrease in the interatomic spacings upon their formation, just as upon the formation of conventional vacancies in the bulk of metals. The vibrational energy of the nearest environment of the vacancies that are formed in the CCR cores in the polycrystalline d transition metals with a bcc lattice decreases because of a negative “relaxation” contribution to the change in the force constants. The cores of the high-angle CCRs in polycrystalline d transition metals with a bcc lattice are characterized by a negative internal pressure. Therefore, vacancies with positive relaxation volumes ν_BCC > 0 are formed in them, causing an increase in the interatomic distances in the nearest environment of such vacancies.     

NbFe合金的生产现状和发展

评述了中国及世界主要的NbFe合金生产厂家的生产能力、现状及世界钢铁工业对NbFe合金的需求状况,展望了中国NbFe合金的未来发展趋势.巴西CBMM公司是世界上最大的NbFe合金生产企业,最近几年NbFe合金生产能力已有相当大的提高,NbFe合金产量占世界总产量的70%以上,其中出口约14 800t.中国钢铁中铌的平均含量仅为美国和欧洲的15%,因此来自中国铌的需求量至少有6倍的增长空间.宁夏东方有色集团金联公司是中国最大的NbFe合金生产厂家,其NbFe合金生产量快速增长,2005年上半年达580t,占中国NbFe合金产量的75%以上.     

Synthesis and characterization of electrodeposited Ni-Pd alloy electrodes for methanol oxidation

A wide compositional range of Ni-Pd alloy catalysts were prepared by electrodeposition for use as anode materials for methanol oxidative fuel cells in alkaline conditions. Structural characterization of the electrocatalysts in their as-plated condition revealed that the Ni-Pd catalysts synthesized were nanocrystalline, single phase, face centered cubic materials, indicating the formation of complete solid solution in the alloy. Compositional analysis of the alloys indicated that the palladium composition of the alloy increased with decrease in current density. This change in the composition of the alloy resulted in a shift in the X-ray diffraction peaks. The percentage shift in the d-spacing calculated from X-ray diffraction is in good agreement with percentage of palladium in the alloy. The electrocatalysts prepared are active for methanol oxidation in alkaline medium.     

Grain boundary segregation of phosphorus in iron-vanadium alloys

Grain boundary segregation of phosphorus has been studied in Fe---V---P and Fe---V---P---C alloys through fracture experiments in a scanning Auger microprobe with the objective of examining the effects of vanadium on the interaction processes operative under circumstances when the structure in the interior of the grain (in the present case carbide formation) and grain boundary segregation occur simultaneously. It is understood that to predict and analyse the behaviour of an alloy, it is pertinent to consider the atomic interactions both at the grain boundaries and in the grain interior and that between the constituents and the grain boundaries. The study suggests that the determining factor for suppression or decrease in the migration of phosphorus to the grain boundaries is whether vanadium is present in the combined form (say, carbide) or is available in solid solution form. When vanadium is present in solid solution form, grain boundary segregation of phosphorus is low because of the chemical interaction of vanadium and phosphorus. However, as carbon is increasingly introduced in the alloy, vanadium now preferentially interacts with carbon in view of a higher interaction for carbon as compared to that of phosphorus. A consequence of this is an increase in the grain boundary concentration of phosphorus. In such a situation, the presence of excess carbon in addition to what is stoichiometrically required to precipitate the entire vanadium as vanadium carbides serves as a palliative with regard to the reduction in the intergranular concentration of phosphorus. This palliative behaviour is explained in terms of the site-competition model. An effort is also made to examine the behaviour of segregating elements in terms of a whole range of probable interactions (both at the grain boundaries and in the grain interior) and chemical interaction energies.     

Photoluminescence in nanocomposites based on PVDF + ZnS

The photoluminescence properties of nanocomposite materials based on polyvinylidene fluoride (PVDF) with a filler of ZnS are studied in the wavelength region of λ = 300?1000 nm. PVDF powder with a particle size of 0.5–1.0 μm is used as the matrix. It is shown that an increase in the concentration of the initial solutions leads to an increase in the size of the ZnS nanoparticles in the PVDF; that is, in the process of the cluster formation, the coalescence of the ZnS particles into a nucleation center takes place. It is also found that the composites exhibit a shift of their luminescence bands to shorter wavelengths at a decrease in the concentration of nanoparticles in the matrix and, consequently, in the size. This can be explained by both the reabsorption of the luminescence in the optically dense scattering sample and a change in its spectral composition.     

海水环境中微生物附着对钝性金属开路电位的影响

采用电化学技术和荧光显微技术研究了微生物附着对钝性金属在海水中开路电位的影响．研究中发现，在自然海水中。钝性金属的开路电位逐渐正移达300mV．显微镜原位观察表明，浸入海水后，微生物在金属表面逐渐寄居附着。形成微生物膜．微生物的数量与开路电位按相同方式增加．但在灭菌海水中以及铜电极情况下，开路电位保持不变，微生物也很少附着在表面上．此外，钝性金属界面双层电容在自然海水中逐渐减少。但在灭菌海水中，由于没有微生物膜存在。电容值保持不变．这些结果证实，微生物在表面的附着和寄居生长是导致钝性金属开路电位正移的主要原因．     

Electron microscopy of ion beam thinned porous anodic films formed on aluminium

Ion beam thinning of porous anodic films formed on aluminium in the major anodizing acids enables observation of the apparent film material substructure to be made upon subsequent examination of the thinned regions in the electron microscope. In addition to irregular pore section shapes and distorted cellular morphology, cell boundary bands are evident for the films formed in phosphoric and oxalic acids. The presence of the bands seems related to the growth mechanism and composition of the porous anodic film. For films formed in chromic and sulphuric acids no cell boundary bands are evident, possibly due to the low level of chromate incorporation in the former and the similar nature of the particle size distributions of the film material regions in the highly anion-contaminated film in the latter. Remarkable changes in the apparent film material substructure are observed for films exposed further to the electron beam. Whether this phenomenon relates to a drying out process, sintering or agglomeration in the electron microscope or to some type of crystallization phenomenon is not yet known. It is possible that the extent of “opening up” of the cell walls, or the acid anion content of the cell walls being greater next to the pores than in the cells remote from the pores, conditions the morphology observed for the films formed in phosphoric and oxalic acids. The low level of chromate incorporated in films formed in chromic acid and the large level of sulphate incorporated in films formed in sulphuric acid may govern the behaviour in the respective cases.     

21世纪首10年我国有色金属铸件生产及市场前景

有色金属铸件产量在铸件总产量中的百分比，反映出一个国家汽车生产的各方面水平。我国的这一百分比比工业发达国家低很多，说明我国有色金属铸件的发展有很大的空间。在21世纪的首10年内，我国汽车工业将会有很大发展，加上由于各种产品轻量化的趋势，促使产品尽量采用轻型铸件，轻合金铸件产量在我国将会有较大的增长，其中尤以镁合金铸件为最。许多新工艺将得到应用，砂铸自动线也会在有色金属铸造厂中涌现。我国的有色金属铸造工业将大有可为。