-
1.用于尖晶石涂层AISI441铁素体不锈钢性能改进的表面处理
[金属制品业,黑色金属冶炼和压延加工业] [2015-09-02]
Ferritic stainless steels are promising candidates for IT-SOFC interconnect applications due to their low cost and resistance to oxidation at SOFC operating temperatures. However, steel candidates face several challenges, including long term oxidation under interconnect exposure conditions, which can lead to increased electrical resistance, surface instability, and poisoning of cathodes due to volatilization of Cr. To potentially extend interconnect lifetime and improve performance, a variety of surface treatments were performed on AISI 441 ferritic stainless steel coupons prior to application of a protective spinel coating. The coated coupons were then subjected to oxidation testing at 800 and 850 degrees C in air, and electrical testing at 800 deg C in air. While all of the surface-treatments resulted in improved surface stability (i.e., increased spallation resistance) compared to untreated AISI 441, the greatest degree of improvement (through 20,000 hours of testing at 800 deg C and 14,000 hours of testing at 850 deg C) was achieved by surface blasting.
关键词:合金;尖晶石;不锈钢;表面处理;涂料
-
2.Meoscale变形金属的统计力学建模—最终报告
[金属制品业,黑色金属冶炼和压延加工业] [2015-09-02]
The research under this project focused on a theoretical and computational modeling of dislocation dynamics of mesoscale deformation of metal single crystals. Specifically, the work aimed to implement a continuum statistical theory of dislocations to understand strain hardening and cell structure formation under monotonic loading. These aspects of crystal deformation are manifestations of the evolution of the underlying dislocation system under mechanical loading. The project had three research tasks: 1) Investigating the statistical characteristics of dislocation systems in deformed crystals. 2) Formulating kinetic equations of dislocations and coupling these kinetics equations and crystal mechanics. 3) Computational solution of coupled crystal mechanics and dislocation kinetics.
关键词:金属;统计力学;耦合;晶体;变形
-
3.低成本钛合金在生物医学应用的研究和发展
[医药制造业,金属制品业] [2014-09-26]
β-type titanium alloys comprising low cost elements such as Fe, Mn, Cr, Sn, Al, O and N and having low Young's modulus are currently being developed. Examples of such alloys include Ti-10Cr-Al, Ti-Mn, Ti-Mn-Fe, Ti-Mn-Al, Ti-Cr-Al, Ti-Sn-Cr, Ti-Cr-Sn-Zr, Ti-(Cr, Mn)-Sn, and Ti-12Cr. Ti-5Fe-3Nb-3Zr belongs to that class of titanium alloys in which rare metals such as Nb, Ta, and Zr have been reduced using Fe. Ti-5Fe-3Nb-3Zr has a Young's modulus of around 76 GPa and has greater strength than that of Ti-6Al-4V ELI for biomedical applications. The characteristics of Ti-5Fe-3Nb-3Zr and other low-cost beta-type titanium alloys with low Young's moduli are discussed from the viewpoint of biomedical applications.
关键词:β型钛合金;低的杨氏模量;低成本元件;普通金属;间隙元素;生物医学应用
-
4.使用铁(FOR)-镓(Ga)合金的磁致伸缩分流阻尼器性能评价
[金属制品业,橡胶和塑料制品业] [2014-08-09]
关键词:阻尼;镓合金;铁;水利;磁致伸缩
-
5.用于髋关节植入物应用的生物医药联合合金发展
[金属制品业,医药制造业] [2014-07-29]
The development of cobalt alloys for the development of HIP implants has been evolving overtime. Accordingly, in this work an overview of the main microstructural factors that impact the mechanical properties, as well as the effect of interstitials such as carbon and nitrogen. In addition the role alloy pre-straining and heat treating on the amount of ε-martensite and on the exhibited mechanical properties is described. In general, it is shown that as the amount of ε-martensite exceeds 60 vol. percent, the alloy ductility is drastically reduced as the HCP phase becomes dominant in the matrix.
关键词:生物医学钴合金;植入物;ε-马氏体;医药制造业;力学性能
-
6.可逆的石墨烯加氢金属接触
[化学原料和化学制品制造业,金属制品业] [2014-07-28]
We use x-ray spectroscopy and density functional theory to investigate the hydrogenation-induced electronic structure changes in graphene on Pt(111). The atom-specific properties of the spectroscopy allow for a direct projection of the band structure onto the carbon atoms; this was compared with the calculated density of states. Instead of the generally expected band opening behavior, we observe states at the Fermi level in the carbon-projected density of states. Hydrogenation is accompanied by pinning of the graphene to the substrate through the formation of local CPt bonds which cause the graphene layer to become metallic upon hydrogenation.
关键词:加氢;可逆;石墨烯
-
7.射击喷丸钢样品疲劳试验中的残余应力演化过程
[金属制品业] [2014-07-27]
Directly-generated compressive residual stress has become a widely used surface modification technique. Intentional residual stress in solid materials can be produced by different surface compression methods. It is well known how residual stress field is influenced by the parameters of the shoot peening but only few articles address the phenomenon about the evolution of the stress during the operation of the machine component. The literature on residual stress decrease caused by fatigue load is scarce and the kinetics of this mechanism is not yet investigated. The present work reports on the examination of the effect of the fatigue load on compressive residual stress strengthened specimens. Investigations have been conducted at three stress levels. Residual stress data have been measured by X ray diffraction method before fatigue load and measurements have been repeated after defined fatigue cycles.
关键词:钢铁;残余应力;X射线衍射仪;疲劳
-
8.金属加工控制系统的性能监控
[信息传输、软件和信息技术服务业,金属制品业] [2014-07-27]
The number of control loops used in process industry is growing continuously, whilst manpower is being reduced. Consequently even companies that have embraced new control technologies struggle to maintain satisfactory performance over the long term. Numerous investigations have shown that the performance of control systems in the process industries is not satisfactory, as mentioned in Chap. 1. This particularly applies for the steel industry, where it is the norm to perform controller tuning only at the commissioning stage and then never again. A loop that worked well at one time is prone to degradation over time unless regular check and maintenance is undertaken.
关键词:钢铁;回路;控制系统;调试
-
9.2012年2月9日密西根州南菲尔德对于汽车轻量化实施先进高强度钢车间的关键技术差距
[金属制品业,汽车制造业] [2014-07-27]
The six important technical areas were selected by the workshop organizing committee, a group of experts from the auto and steel industries, and scientists from several National Laboratories. These selections were based on areas where there were known technical gaps, which if closed would have high impact on accelerating vehicle lightweighting with AHSS. The selected areas were: Steel Development, Fracture, Plasticity, Delayed Fracture/Hydrogen Embrittlement, Modulus Characterization and Joining. The main output of the workshop is contained within the breakout session reports, which summarize the technical requirements, engineering gaps and research needs. The breakout session reports are included below in the main workshop report.
关键词:钢铁;汽车;材料加工;车间;汽车燃料
-
10.金属学板材中心质量建模的工业软件经验实施
[金属制品业] [2014-07-26]
Recognizing the central quality of a metallographic sample represents, for a metallographic laboratory expert, a challenging task involving analyzing the size and number of defects at the evaluated segment. In order to help human experts, a software tool was developed for machine evaluation of these metallographic samples. The aim of the paper is to present the properties of the developed software and to demonstrate its practical application in industry. The developed software tool is based on the machine recognition of small but important non-homogeneity objects located at the central part of the metallographic sample and on a statistical evaluation of the properties of these extracted central objects. Because the central objects are very similar to noise, machine recognition is not straightforward. However, this paper contains promising results of comparing machine and expert assessments of an industrial image database of digitized metallographic samples. The image database is provided by the research department of ArcelorMittal Ostrava, a.s., in the Czech Republic.
关键词:钢铁;材料科学与技术;质量控制;控制系统