Substitution of graphite in powder metallurgical steels with carbon from petroleum products

Abstract

This paper reviews the mechanical and microstructural characteristics of hypoeutectoid steels obtained by powder technology, in which various carbonaceous petroleum products provide the carbon constituent. These steels are compared with others of similar composition obtained from graphite.     

Production of railroad rails from continuous-cast semifinished products

Ukrainian Scientific-Research Institute of Metallurgy (UkrNIImet). Kuznetsk Metallurgical Combine. Azovstal Metallurgical Combine. Translated from Metallurg, No. 7, pp. 33–34, July, 1989.     

Multistage sintering process for Ni3Al powder metallurgical products

A multistage sintering process for powder metallurgical products of nickel aluminide intermetallic compound has been investigated. It comprises at least two stages of sintering and interstage cold deformation to collapse and eliminate the sintering pores. Most of all, a thermally absorbing material has to keep in contact with the powder compacts during the preliminary heating stage (650 °C, the first stage of reactive sintering). It depresses the maximum temperature of specimens to develop the useful transient phase Ni₂Al₃. This transient phase is a brittle and especially crispy material with a relatively low melting point (1135 °C). It plays an important role in preventing the development of any significantly large cracks during the pore-eliminating process. The purpose of the second stage of sintering material at an elevated temperature (1200 °C) is to develop a transient liquid phase from the Ni₂Al₃ to heal or eliminate any microcracks, crazes, and collapsed pores from previous steps, as well as to transfer the material to the final Ni₃Al structure. It is beneficial to produce a sound product having a large dimension and excellent mechanical properties. Consequently, the specimens will be further densified by a repeated cycle of thermal mechanical treatment (TMT).     

The development of new metallurgical materials and technologies. Part 1

Work by researchers at the Russian Academy of Sciences on new materials (metals and ceramics) and new technologies is reviewed. The topics include new high-strength corrosion-resistant nitrogen steels; high-temperature light alloys and composites based on intermetallics; modifiers for wheel steels; complex ferroalloys containing V, Cr, and Ni; anticorrosive protective coatings based on ultrafine Zn powders; catalytic converters for vehicle exhaust gases; magnetically hard materials with high temperature–time stability and excellent mechanical characteristics; nanostructured stents for endovascular operations; and corrosionand wear-resistant coatings and corresponding methods of plasma application. Methods have been developed for longitudinal rolling with shear deformation to improve the properties of the rolled product; recycling of oily scale; monitoring of the wear of the refractory lining at any point of the blast-furnace hearth; and monitoring of the content of inclusions in rail steel. Technologies have been developed for special electroproduction of steel for the power industry; synthesis of massive monocrystalline samples of transition-metal nitrides and nanopowders of W, Pt, and Ti and their carbides and nitrides; the processing of leucoxene concentrates from the Yareg Basin; the production of titanium implants with porous coatings; ferrous and nonferrous metal shot and powder; ultrafine Zn powder; recycling of metallurgical wastes with the extraction of Zn, Sb, Sn, and Fe; the production of sintered nanocrystalline Ta powder for capacitors; the processing of molybdenum-bearing sulfide material to obtain rare-earth metals, MoO₃, and CaMoO₄; and the utilization of sulfur dioxide. Injection units and technologies for their use have been developed, as well as high-speed systems for the plasma application of metals on surfaces including paint coatings, plastics, and cardboard. Data have been obtained regarding the thermodynamic functions of the solution of oxygen in Fe-based melts and the reactions of elements dissolved in such melts (Cr, Mn, Nb, V, Si, B, C, Ti, Zr, Al) with oxygen.     

羰基法从含镍废催化剂中回收镍的研究

进行了从废雷尼镍催化剂中回收镍的研究，重点研究了废雷尼镍催化剂的预处理条件以及羰基合成的温度、CO压力等对羰化合成率的影响。     

羰基法从含镍废催化剂中回收镍的研究

进行了从废雷尼镍催化剂中回收镍的研究,重点研究了废雷尼镍催化剂的预处理条件以及羰基合成的温度、CO压力等对羰化合成率的影响。