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TREATMENTS

JPRS-UMS-92-003 16 March 1992

The Effect of Cycling on the Crack Formation of Austenite Chromium Manganese Steel Intended for Use in a Controlled Thermonuclear Reactor

927D0049K Moscow FIZIKA IKHIMIYA OBRABOTKIMATERIALOY in Russian No 3, May-Jun 91 (manuscript received 14 May 90) pp 135-139

[Article by S.Ye. Gurevich, Ye.V. Demina, L.D. Yedi-dovich, and M.D. Prusakova, Moscow]

UDC 669.018.6:539.43

[Abstract] The authors of the study examined the cyclic crack resistance of Crl2Mnl4Ni4AlMo austenite chro-mium-manganese low-nickel Steel in five versions. The five versions of Crl2Mnl4Ni4AlMo Steel studied dif-fered from one another with respect to boron, cerium, and scandium content. The test steels were smelted by the method of open induction melting by using the conventional charge materials. Cerium and boron were added to the melt after it had been killed. They were added in form of ferrocerium and ferroboron. The scandium was added in its metallic form directly to the stream of molten metal as it was poured into the ladle. The resultant ingots (weight, 150 kg) were subjected to hot and cold rolling into sheets 1.5 mm thick under standard plant conditions. Cyclic crack resistance was studied at room temperaturę, and the mechanical prop-erties of the five versions of the Steel were determined in specimens with a working section 22 mm long and 3 mm wide. When subjected to static stretching, all of the specimens had very similar mechanical properties. The Steel with the greatest cyclic crack resistance (both in a work-hardened State and after annealing) had the fol-lowing Chemical composition (% by weight): Sc, 0.15; C, 0.055; Si, 0.67; Mn, 13.8; Cr, 12.3; Mo, 0.45; Ni, 4.32; and Al, 1.31. In generał, additions of scandium to the basie Steel composition were found to inerease cyclic crack resistance. Adding extra scandium in place of boron was found to reduce the threshold amplitudę of the stress intensity coefTicicnt (AK^,) and the actual amplitudę of the stress intensity coefficient (AK_a). Com-bining scandium and boron was found to reduce AK_xh somewhat but did not have any negative effect on AK₀. Replacing boron by scandium when cerium was present did not inerease resistance to the formation and growth of fatigue cracks. The reduction in AK_a and AK_th amounted to 11.0-12.7% for materiał in its shipped State and 11.7-12.7% after annealing. Cold deformation of Crl2Mnl4Ni4AlMo Steel in the amount of 10% was found to have a positive effect on cyclic crack resistance: it inereased the amplitudę and threshold amplitudę of the stress intensity coefficient and noticeably reduced the ratę of fatigue crack formation. Figures 4, tables 4; references 7: 4 Russian, 3 Western.

Structural Changes in Polycrystalline Scandium Oxide Upon łon Irradiation

927D0089A Moscow FIZIKA I KHIMIYA OBRABOTKI MATERIALOV in Russian No 6,

Nov-Dec 91 (manuscript received 14 May 90) pp 5-11

[Article by A.Ye. Solovyeva, E.M. Diasamidze, V.L. Markov, Sukhumi]

UDC 661.863.1:620.181.001.5

[Abstract] The authors of the study examined the structural changes occurring in polycrystalline scandium oxide after irradiation by Xe⁺ ions at an energy up to 300 keV. Polycrystalline test specimens were prepared from type OS-99.9 Sc₂0₃ powder in accordance with a method described elsewhere and then annealed at 1,800° in a vacuum (holding time, 5 hours) and oxidized at 1,400° in air until a constant weight was achieved. The specimens prepared for the irradiation represented a mixture of two phases—an ordered phase and a type C disordered phase as described elsewhere. łon irradiation was found to result in an alteration of the scandium oxide’s Chemical composition that was accompanied by phase transformations. After irradiation, the specimens* cubic structure was found to contain macro- and micros-tresses that were highly dependent on irradiation energy. An inerease in the relative integral intensity of the specimens* reflecting planes was observed, with the maximal values recorded at a depth of 3 to 4.6 pm (which is connected with a change in the atoms’ electron density). Analysis of the change in free energy of the processes of the reduction of scandium oxide after irradiation by Xe⁺ ions revealed that after ion irradiation in the amount of 140 keV, the free energy changes with an amplitudę that becomes weaker deeper into the spec-imen until a depth of 3.5 pm (in the interval from 3.5 to 6 pm the lines virtually disappeared). Irradiation at an energy of 300 keV was found to result in smali fluctua-tions of free energy to a specimen depth of 3 pm. Figures 6, table 1; references 15: 11 Russian, 4 Western.

The Erosion of Quartz Under the Effect of High-Power Nanosecond łon Beams

927D0089C Moscow FIZIKA I KHIMIYA OBRABOTKI MATERIALOY in Russian No 6,

No\-Dec 91 (manuscript received 29 Jan 91) pp 25-32

[Article by V.P. Krivobokov, O.V. Pashchenko, G.A. Sapulskaya, and B.P. Stepanov, Tomsk]

UDC 537.534.9:621.785.5

[Abstract] The authors of the study performed a series of calculations to establish the erosion kinetics and phase transformations of quartz surfaces irradiated by high-power nanosecond ion beams. The calculations estab-lished that nanosecond beams of accelerated ions in the energy interval studied cause intensive erosion of quartz surfaces due to vaporization. The erosion coefficient was