Surface alloying of iron-carbon alloys using laser heatingChudina, O.
doi: 10.1007/BF01401080pmid: N/A
In recent years, laser radiation has been increasingly used for surface treatment of machine and tool parts. In cases when laser technologies can be cost-competitive, they have begun to displace traditional treatment methods. In this paper, we consider the structure of low- and medium-carbon structural steels after surface alloying using laser heating.
Improvement in the high-temperature strength of alloys based on cobalt by internal nitridingPetrova, L.
doi: 10.1007/BF01401081pmid: N/A
Internal nitriding, as for internal oxidation, may be considered as a particular case of material dispersion strengthening. Internal nitriding is accompanied by preparation of a heterophase structure of a diffusion layer: The matrix is a solid solution with fine particles of alloying element nitride particles distributed within it. Internal nitriding may be special importance as a version of dispersion hardening for high-temperature alloys. Possibilities are considered in this article for internal nitriding of cobalt alloys.
Endurance of high-temperature materials with a complex stressed stateTrunin, I.
doi: 10.1007/BF01401082pmid: N/A
Materials used in power engineering operate under creep conditions with a stressed state which as a rule differs from uniaxial tension (for example the metal of pipe systems, steam admission valves, turbine disks, etc.). At the same time the heat resistance characteristics for these materials are normally determined from tests in uniaxial tension at constant temperature. A method is suggested in this article for determining the endurance of alloys used for elements of equipment which operate under a complex stressed state.
Structure and properties of deformable nickel alloys for gas turbinesFilatova, M.; Sudakov, V.
doi: 10.1007/BF01401083pmid: N/A
The construction of high power gas turbine installations necessitates the development and use of new high-strength heat-resistant nickel alloys for large forged turbine blades. The blade material must possess not only superior properties (high temperature strength, ductility, fatigue and thermal fatigue strength, stability in the fuel combustion products) but also the required level of metallurgical and manufacturing producibility. The results of a study of the deformable nickel alloys KhN65KVMYuTB (ÉK78), KhN65KMVYuB (ÉP800), and KhN60KVYuMB (ÉP957), which have substantially better properties than the alloy now used for gas turbine blades (KhN65VMTYu) (ÉI893), are presented in this article.
General laws governing variation in properties of cast alloys of the Al-Zn-Mg systemCherkasov, V.; Dolzhanskii, Yu.; Pobezhimov, P.
doi: 10.1007/BF01401085pmid: N/A
Among existing high-strength corrosion-resistant aluminum alloys, those of the Al-Mn-Zn system are most promising. They have a different phase composition, depending on the content of magnesium and Zinc: α + β(Al3Mg2), α + β + T(Al2Mg3Zn3), α + T, α + T + η (MgZn2) and α + η The majority of industrial Al-Mg-Zn alloys correspond to the phase regions α + T and α + T + η with respect to composition. A high level of strength and satisfactory overall corrosion resistance are characteristic for these alloys. Al-Mg-Zn alloys may, however, tend to the most dangerous form of corrosion - stress-induced corrosion cracking. Using methods of experiment planning in the study, we investigated Al-Zn-Mg alloys of various compositions for the purpose of selecting alloy compositions with a high level of mechanical properties and stress-induced corrosion cracking.
Distinctive features of primary crystallization in alloy 1570Kolerov, O.; Logvinov, A.; Tregub, V.
doi: 10.1007/BF01401086pmid: N/A
The study of primary recrystallization processes in deformable aluminum alloys that have not been hardened by heat treatment makes possible a substantiated choice of technological conditions for pressure shaping. The data from metallographic analysis of the primary recrystallization of alloy 1570 are inadequate in comparison with the data for its industrial analog, alloy AMg6. In view of this we studied the distinctive features of primary recrystallization in semi finished alloy 1570 strip.
Method of testing gear wheels in impact bendingTikhonov, A.; Palagin, Yu.
doi: 10.1007/BF01401087pmid: N/A
Chemicothermal treatment processes are widely used in engineering to improve the working lives of important components, of which the most common is nitrocementation. That process has been applied at the Volga Automobile Plant mainly to sprockets in gear transmissions, which need high hardness and wear resistance in the surfaces with relatively ductile cores. Although various forms of chemicothermal treatment are widely used, there has been no universal method of evaluating the strengths of gear wheels. Standard methods of estimating strength (σu, σt, σb, and hardness) have a major shortcoming: They can determine only the characteristics of the cores for case-hardened materials. Here we consider a method of impact bending test, which enables one to evaluate the actual strength of gear teeth.