Metal Science and Heat Treatment

Ababkov, V.; Morgunova, N.; Belyasov, B.; Goldovskii, V.

doi: 10.1007/BF00679375pmid: N/A

1. Melting of Mo−W alloys with >20% W requires more power than melting of unalloyed molybdenum or tungsten. The power required is highest for melting alloys with 80–85% W. 2. Alloys with 17–85% W have considerably finer grains as-cast than unalloyed molybdenum or tungsten; the grains are finest for the most highly alloyed alloy (Mo+56%W). 3. With increasing tungsten concentrations the density of Mo−W alloys increases, reaches a peak for the alloy with 60% W, and then declines. 4. At low (20°) and high (1800°) temperatures the strength characteristics of Mo−W alloys increase with the tungsten content; at moderate temperatures (400–1600°) the strength is highest for the alloys most highly alloyed. Alloying of molybdenum with tungsten reises the temperature range in which molybdenum exhibits hot shortness. The ductile-britle transition temperature increases most when over 85% W is added.

Parshikov, V.; Leitman, M.; Shchukin, A.; Pruzhinina, N.

doi: 10.1007/BF00679376pmid: N/A

1. Heterogeneity of the chemical composition and hardness in micro-and macrovolumes is observed in ingots of molybdenum and tungsten alloys. The large carbide inclusions in the ingots are the result of uneven solidification. 2. Prolonged high-temperature annealing partially removes the chemical heterogeneity in ingots of the molybdenum alloy, leading to solution of the large carbides and improving the plasticity. Annealing of the tungsten alloy equalizes the hardness through the section of the ingot.

Naumkin, O.; Koroleva, I.; Biryukova, T.; Shchukin, A.

doi: 10.1007/BF00679377pmid: N/A

1. We constructed recrystallization diagrams for alloy TSM-4. The initial recrystallization temperature is 1250–1600°, depending on the degree of deformation. The recrystallization process is completed at 1700–1800° at all degrees of deformation investigated. 2. Finely dispersed carbide phases delay secondary recrystallization until solution of excess phases (∼2000°). 3. The plasticity is highest and the anisotropy of the properties along and across the rolling direction is lowest for plates of alloy TSM-4 annealed at 1300° for 1 h.

Savchuk, A.; Ol'shanetskii, V.; Krasnova, G.

doi: 10.1007/BF00679378pmid: N/A

1. In the case of diffusional contact with the Ni−Cr matrix in a molybdenum filament (regardless of the degree of alloying) recrystallization processes occur during prolonged holding at high temperatures, leading to weakening of the composite. 2. A powdered mixture of the Cr+W+Mo type added to the contact zone in a composite of KhN78T ⌈ alloyed molybdenum prevents unfavorable structural changes in the filament and transition zone between the matrix and the filament, so that the strength of the composite is retained.

Karpinos, D.; Kadyrov, V.; Moroz, V.; Didyk, V.

doi: 10.1007/BF00679379pmid: N/A

Metallographic and microprobe analysis were used to investigate the kinetics and characteristics of the solid-phase interaction of AD1 aluminum with reinforcing filaments of maraging steel N16K4M5T.

Ol'shevskii, A.; Mirotvorskii, V.

doi: 10.1007/BF00679380pmid: N/A

Chernykh, N.; Arsen'ev, V.; Turitsina, A.; Sosnovskaya, T.

doi: 10.1007/BF00679381pmid: N/A

1. Heat treatment of bimetals with a cladding layer of steel Kh18N10T and holding at elevated temperature lead to diffusion of carbon into the cladding layer, the effect increasing with less alloying of the base metal. 2. The carburized zone in the two-layer steel induced by carbon diffusion lowers the ductility, which must be taken into account in welding, heat treatment, and operation of apparatus manufactured from two-layer steels.

Pervukhin, L.; Mal'tsev, V.; Konon, Yu.; Tsemakhovich, B.; Chudnovskii, A.

doi: 10.1007/BF00679382pmid: N/A

1. The magnitude of internal stresses in bimetal 22K+Kh18N10T and the character of their distribution depend greatly on the heat treatment, after which the stresses in the cladding layer decrease and may even change in sign. 2. The internal stresses tend to decrease with increasing heat treatment temperatures, which makes it possible to reduce the stresses by proper selection of the heat treatment conditions. 3. The reason for the growth of fatigue cracks from the joint in repeated static tests is the substantial gradient of internal stresses at the joint between the two components.

Chervyakov, V.; Golovanenko, S.; Bykov, S.; Ustimenko, V.; Tkachev, A.

doi: 10.1007/BF00679383pmid: N/A

Kireev, V.; Abramov, O.; Abramov, I.

doi: 10.1007/BF00679384pmid: N/A

1. Additions of Ti, Y, Zr, and Mg lead to even distribution of particles of hardening phase (ZrO2, Al2O3, HfO2) in a Nichrome matrix (Kh20N80) in the production of cast composite material. 2. Additions of these elements lead to an increase in the microhardness of the dispersion-hardened composite, which is explained by the increase in the “assimilation“ of the hardening phase by the matrix and its more even distribution in the matrix.