Alexandrov N.N. Synthesis Of New Structural Materials And Advanced Casting Technologies
Gushchin N.S. Peculiarities Of Enhancing Corrosion-and-Abrasion Resistance of Chromium-Nickel Cast Iron
Based on the results of investigation into the distribution of chromium and vanadium in chromium-nickel cast iron, it has been found that the chromium concentration in metallic samples can be increased not only by increasing the chromium content in cast iron, but by isolating a portion of structurally free carbon and additionally adding vanadium to the cast iron. Tests of wheels made of ЧЧХ8НФШ grade cast iron have confirmed their high abrasion-and-corrosion resistance.
Kovalevich Y.V. Methods of Cast Iron Inoculation to Produce Globular Shape of Graphite
The most well known methods of producing nodular cast iron when inoculating it with pure magnesium and magnesium-containing compositions are discussed. It has been shown that, at present, the method of inoculation with dispersed compositions DMK, which allow, unlike all the known methods, total control of the inoculation process, should be considered the most effective method of ladle inoculation. This allows to produce nodular iron with predetermined properties in common pouring ladles at high magnesium assimilation and observation of the sanitary code.
Andreyev V.V. Peculiarities of Formation and Morphology of Graphite-Austenitic Eutectics in Cast Irons
Based on the investigations into the main parameters of cast irons' liquid state, thermographic analysis of their solidification involving the structural-hardening method, peculiarities of the process of formation of graphite-austenitic eutectics in cast irons with different shapes of graphite inclusions have been studied. Morphology of graphite inclusions has been investigated by special methods of etching and scanning electron microscopy. It has been shown that such "degenerate" shapes as "coral-like", "honeycomb" or "chunky" graphite forming in thick-walled castings on the boundaries of primary eutectic colonies of vermicular or spheroidal graphite - a product of eutectic crystallization of graphite and austenite - have virtually the same morphology of graphite inclusions at the cut of metallographic sample's surface, but form on different stages of liquid iron's solidification differing by chemical composition, crystallization temperature and degree of melt undercooling, depending, in its turn, on the intensity of heat removal and presence of effective nuclei of crystallization.
Andreyev V.V. et al. The Role of Active Elements in Enhancing Effectiveness of Graphitizing Inoculants
By the example of barium, the influence of active elements in the composition of graphitizing inoculants on the effectiveness of their action on the structure and properties of flake graphite cast irons has been examined. Experimental investigations have not revealed direct influence of any barium compounds on the graphitizing effect, as there are no such compounds in solidified cast iron. Proceeding from the character of the processes running in the melt at introducing silicon-containing inoculants with active elements having increased affinity with oxygen, there are no grounds for speaking about the leading role of those elements in creating additional nuclei of crystallization in the form of oxides or other nonmetallic inclusions complex in composition. The high graphitizing effect of such additives is related to the formation, in the immediate vicinity of dissolving inoculant particles, of local melt zones with higher silicon content and low oxygen content, which stimulates in those microvolumes the activation of the already existing graphite nuclei and the spontaneous origination of new ones, based on which graphite inclusions form during the subsequent eutectic crystallization.
Usmanov R.G. et al. Comparative Investigation into the Effectiveness of Graphitizing Inoculants with Different Barium Contents
Results of comparative tests of the effect of graphitizing Fe-Si-Ba master alloys containing about 4, 12, 25 and 35% Ba, respectively, on the structure and mechanical properties of flake graphite cast irons are presented. Owing to a deeper action on the process of cast iron crystallization than only removal of chilling effect or elimination of structurally free cementite, the inoculation with high-percent silicobarium (25% Ba) allows enhancing (by 10…20%) the strength characteristics of cast iron due to forming a denser and finer metal structure in the casting.
Fukalova Y.V. Choosing Optimum Conditions of High-Temperature Treatment of H-2,5 Alloy, Taking into Consideration the Kinetic Peculiarities of its Oxidation
The kinetic peculiarities of oxidation of a commercial zirconium-based H-2,5 alloy as compared with zirconium are discussed. Experimental data on the variation of the thickness of the ZrO2-σ film and its relation to the thickness of the oxygen solid solution layer in the metallic base, formed at different temperatures and Po2i at the oxidation of the H-2,5 alloy during 30 minutes are given. Optimum conditions of high-temperature treatment of H-2,5 alloy products to produce a thick, protective, heat-resistant electroconductive film on their surface are given.
Romashkin V.N. et al. Burn-on Preventing Materials and Technologies by the Casting Surface Quality Laboratory
Investigations into the protective mechanism of mold's resisting the formation of a number of surface defects allowed to establish the relationship between the destruction of the mold by thermal impact strains and the character of forming surface defects. Compositions of defect-preventing molding sands have been developed: fillers and binders have been selected, and burn-on preventing coatings have been developed.
Yurin Y.M. Temperature Fields in Castings and Molds of Steel Marine Propeller Blades
For preventing shrinkage-liquation defects in a marine propeller casting, the character of their solidification was investigated. An optimal mold design has been proposed.To reduce temperature gradient along the length of casting, an equation was deduced for determination of heat flow, in which the dimensionless coefficient n characterizes the process of blade solidification.
Petrov A.F. Patterns Will Be No Longer Required
The article discusses a new method of patternless casting production. Data of experience of practical mastering of the method under the conditions of a foundry operation are given.
Savchenko A.K. et al. Molding Sand Reclamation Technology and Equipment
The articles describes the composition and operation of a department for reclaiming spent cold-hardening sands, introduced at the Amurlitmash foundry and created on the basis of a mechanical sand cleaning apparatus PM-5M designed by KTIAM, Chelyabinsk. Operation of the PM-5M apparatus is described, data on use of reclaimed sands are given.
Degtyarenko G.I., Smolyakov V.S. Review of International information