Astm stp 1046 v1 1990

STP 1046 Effects of Radiation on Materials: 14th International Symposium (Volume I) N H Packan, R E Stoller, and A S Kumar, editors III ASTM 1916 Race Street Philadelphia, PA 19103 Library of Congress Cataloging-in-Publication Data Effects of radiation on materials: 14th international symposium/ N H Packan, R E Stoller, and A S Kumar, editors (STP; 1046) Papers from the Fourteenth International Symposium on Effects of Radiation on Materials, held June 27-30, 1988 in Andover, Mass and sponsored by ASTM Committee E-10 on Nuclear Technology and Applications Includes bibliographies and index ISBN 0-8031-1266-1 Materials Effect of radiation on Congresses I Packan, N H (Nicholas H.) II Stoller, R E (Roger E.), 1951III Kumar, A S (Arvind S.) IV International Symposium on Effects of Radiation on Materials (14th: 1988: Andover Mass.) V ASTM Committee E-10 on Nuclear Technology and Applications VI Series: ASTM special technical publication: 1046 TA418.6.E334 1990 620.1' 1228 -dc20 89-18449 CIP Copyright by AMERICAN SOCIETY FOR TESTING AND MATERIALS 1990 NOTE The Society is not responsible, as a body, for the statements and opinions advanced in this publication Peer Review Policy Each paper published in this volume was evaluated by three peer reviewers The authors addressed all of the reviewers" comments to the satisfaction of both the technical editor(s) and the ASTM Committee on Publications The quality of the papers in this publication reflects not only the obvious efforts of the authors and the technical editor(s), but also the work of these peer reviewers The ASTM Committee on Publications acknowledges with appreciation their dedication and contribution of time and effort on behalf of ASTM Printed in Baltimore MD April 1990 Foreword Effects of Radiation on Materials: Fourteenth International Symposium was presented at Andover, MA, 27-30 June 1988 The symposium was sponsored by ASTM Committee El0 on Nuclear Technology and Applications N H Packan Oak Ridge National Laboratory, presided as chairman of the symposium with R E Stoller, Oak Ridge National Laboratory, and A S Kumar, University of Missouri-Rolla, as vice-chairmen There are two resulting Special Technical Publications (STPs) from the symposium: Effects o f Radiation on Materials: Fourteenth International Symposium (Volumes I and 11), STP 1046 and Reduced-Activation Materials for Fusion Reactors, STP 1047 Contents Overview MICROSTRUCTURES: FERRITICS Behavior and Microstrnctere of Ferritic Steels Irradiated in the Phenix Reactor-DIDIER GILBON, JEAN-LOUIS SI~RAN, RICHARD CAUVIN, ANTOINE FISSOLO, ANA ALAMO, FRAN(~OIS LE NAOUR, AND VIVIANE LI~VY Void Formation and Helium Effects in 9Cr-IMoVNb and 12Cr-lMoVW Steels Irradiated in HFIR and FFTF at 400~ J MAZIASZ AND 35 RONALD L KLUEH Microstructural Change in Ferritic Steels Under Heavy ion Irradiation-KOICHIRO HIDE, NAOTO SEKIMURA, KOJI FUKUYA, HIDEO KUSANAGI, MASAFUMI TAGUCHI, TATSUO SATAKE, YOSHIO ARAI, MASASHI IIMURA, HIROSHI TAKAKU, AND SHIOR! ISHINO Neutron Irradiation Damage in Ferritic Fe-Cr AlloyS DAVID S GELLES 61 73 Influence of Structure and Phase Composition on ICr13Mo2NbVB Steel Mechanical Properties in Initial, Aged, and Irradiated Statesm V S AGUEEV, V N BYKOV, A M DVORYASHIN, V N GOLOVANOV, E A MEDVEDEVA, V V ROMANEEV, V K SHAMARDIN, AND 98 A N VOROBIEV Effects of Thermal Aging on Precipitate Development of Alloy H T - PO-SHOU CHEN AND ROY C WILCOX 114 MICROSTRUCTURES: AUSTENITICS Swelling Suppression in Phosphorus-Modified Fe-Cr-Ni Alloys During Neutron lrradiation EAL H LEE AND NICOLAS H PACKAN 133 Microstructural Evolution of Neutron Irradiated Fe-Cr-Ni Alloys at 495"C in Response to Changes in the Heliam/DPA R a t i o - - J F STUBBINS, J E NEVLING, F A GARNER, AND R L SIMONS 147 Microstructurai Development of Titanium-Modified Austenitic Stainless Steel Under Neutron Irradiation in H F I R up to 57 dpa MASAHIDE SL ZtKI, SHOZO H A M A D A , PHILIP J M A Z I A S Z , M1TSUO P T A N A K A , AND 160 AKIMICHI HISHINUMA The Microstructurai Evolution and Swelling Behavior of Type 316 Stainless Steel Irradiated in H F I R - - s H o z o HAMADA, MASAHIDE SUZUKI, 172 PHILIP J M A Z I A S Z , AKIMICHI H I S H I N U M A , MITSUO P T A N A K A Swelling Resistance of the Highly Deformed Titanium-Modified Austenitic Stainless SteeI JANEZ MEGUSAR 185 Variations of Phase and Structure in Austenitic Stainless Steel Under Heavy Ion l r r a d i a t i o n - - v N V O Y E V O D I N V F ZELENSKY, AND I M N E K L Y U D O V 193 Ion Bombardment Radiation Damage Studies of Fusion-Relevant Austenitic and Ferritic A l l o y s - - D A V I D J M A Z E Y , SUSAN M MURPHY, G PETER WALTERS 203 WILLIAM HANKS, AND D A V I D E J BOLSTER GAS EFFECTS High Temperature Helium Embrittlement: Austenitic Versus Martensitic Stainless 223 S t e e l S - - H E R B E R T S C H R O E D E R AND ULRICH STAMM Helium Effects on Neutron-Irradiated Cr-Mo Ferritic Steels: A Review of Recent Results RONALD 246 L K L U E H AND PHILIP J M A Z I A S Z Microharduess Microstructure Study of Aged Nimonic 90 Irradiated with Helium KAILASANTHAN V A R A T H A R A J A N AND R A J E N D R A V N A N D E D K A R 263 High Temperature Embrittlemeut of Hastelloy X After Low Fluence Neutron Irradiation-An Effect of Helium? BERNHARD A THIELE, H E R B E R T S C H R O E D E R , WILTO KESTERNICH, AND FLORIAN SCHUBERT On the Role of Helium in High Temperature Embrittlement of Irradiated Austenitic S t e e I s - - W l L T O KESTERNICH AND RAJU V N A N D E D K A R Effects of Irradiation on Grain Boundary Deformation in Nickeb v 271 284 ZELENSKY, I M N E K L Y U D O V , L S O Z H I G O V , AND A A P A R K H O M E N K O 295 Helium-Induced Degradation in the Weldability of an Austenitie Stainless Steel H U A T LIN, STEVE H G O O D S , MARTIN L GROSSBECK, AND BRIAN A CHIN 301 lsotopically Alloyed Injector Foils for Helium Effects Research in Mixed-Spectrum Reactors LOUiS K MANSUR AND WILLIAM A C O G H L A N 315 The Growth of Bubbles in Pure Aluminum During and After Irradiation with 600 MeV P r o t o n S - - F R A N C O I S P A S C H O U D , R GO'I-FHARDT, D G A V I L L E T , W V G R E E N , AND M VICTORIA 326 Cavitation and Embrittlement in Tritium Exposed Copper STEVEN n GOODS 340 Modeling Studies on the Precipitation of Krypton After Implantation into Metals JEFFREY REST, R O B E R T C B I R T C H E R , AND A N S H E N G S LIU 353 Simulation of Solid Inert Gas Bubbles in Metals -SUBRAMANYAM SRINIVASAN 364 A S H O K K T Y A G I , AND K A N W A R KRISHAN R A D I A T I O N - I N D U C E D S E G R E G A T I O N OR PHASE C H A N G E S Radiation-Induced Segregation of Phosphorus in Nickel and Fe-Cr-Ni Alloys JONATHAN M PERKS, COLIN A ENGLISH, AND MIKE L JENKINS 379 Characteristics of Radiation-Induced Solute Segregation in Candidate and Model Ferritic A I I o y s m T A K E O M U R O G A , ATSUSHI Y A M A G U C H I , A N D 396 N A O A K I YOSHIDA Segregation to Surfaces in Irradiated Stainless Steels -EDWARD P SIMONEN, 411 E ROSS B R A D L E Y , AND R H JONES Irradiation-Assisted Stress Corrosion Cracking and Grain Boundary Segregation in Heat Treated Type 304 SS -ALVlN J JACOBS, ROBERT E CLAUSING 424 LEE H E A T H E R L Y , AND R I C H A R D M K R U G E R Irradiation-Induced Solid Solution Decomposition Enhances Point Defect Recomhination v v BRYK, V N V O Y E V O D I N , V F ZELENSKY, M N E K L Y U D O V , AND A M PARSHIN 437 Microstructural Development in Neutron Irradiated ZircaIoy-4 -WALTER J S YANG 442 Electron Irradiation-Induced Amorphization of Precipitates in Zircaloy - A R T H U R T M O T T A , D O N A L D R O L A N D E R , A L B E R T J MACHIELS 457 M I C R O S T R U C T U R A L MODELING The Influence of Microstructure and Solutes on Void Formation and Void Growth in Irradiated MaterialS ROGER E STOLLER AND LOUIS K MANSUR 473 The Stochastic Instability of a Spatially Homogeneous Void Distribution in Irradiated Metals: The Distribution Function A p p r o a c h - E D W A R D A KOPTELOV AND A L E X E Y A SEMENOV 490 The Leading Factor Transient Regime of Void Swelling: The Role of Bias Vacancy Flow Around Growing Precipitates aKImICHI HISHINUMA AND KIYOSHI K I U C H I 501 The Development of Periodical Spatial Structures in Crystals Under Irradiation-V L A D l M I R I S U G A K O V Surface Effect on Dislocation Loop Formation TSUNEYUKI H A S H I M O T O 510 523 The Slowing Down of Dislocation Climb by Voids at Later Stages of Material lrradiation v A BORODIN AND A I RYAZANOV 539 Influence of Small Bubble Sink Strength on the Swelling Rate of Voids in Austenitic Stainless Steel AIS! 316 L -JOHANNES TENBRINK RAJESHWAR P WAHl, AND HEINRICH WOLLENBERGER 543 Nucleation of Helium Bubbles at Grain Boundaries During Irradiation-BACHU N SINGH AND ALAN J E FOREMAN 555 Void Ensemble Response to Periodical Variations of Irradiation Conditions-EDWARD A KOPTELOV AND VLADIMIR V KOROLEV 572 F U N D A M E N T A L DEFECT B E H A V I O R An HVEM Study of Displacement Cascade Damage in Nb~Sn at 13 K MARQUIS A KIRK, M I C H A E L C B A K E R , B E R N A R D J KESTEL, H A R A L D W WEBER, AND 587 R O B E R T T KAMPWIRTH A Study of Cascade Cluster Formation and Interaction in Ion-Irradiated Gold by In-Situ Observation NAOTO S E K I M U R A , Y Y A M A N A K A , AND S ISHINO 596 The Production Rate of Freely Migrating Defects in Self-Ion Irradiated Nickel and Fe-Cr-Ni AIIoys A M U L L E R , M.-P M A C H T , AND V N A U N D O R F 609 Alternative Polarity Recombination Centers of Point DefectS ALEXANDER S B A K A J , V L A D I M I R V G A N N , VICTOR F ZELENSKY, 623 AND IVAN M N E K L Y U D O V Estimation of Radiation Vacancy Rate Absorption by Grain Boundaries-E D U A R D U G R I N [ K , V L A D I M I R S KARASEV, A L E X A N D E R YU TOTSKY 632 SPECIAL M E A S U R E M E N T T E C H N I Q U E S Helium Bubbles in Copper Studied by Positron Annihilation -G AMARENDRA, B VISWANATHAN,AND K P GOPINATHAN 639 Study of Helium Diffusion to Grain Boundaries by the Method of Internal Friction EDUARD U G R I N I K , V L A D I M I R S KARASEV, YURIJ P MELNIK-KUTSIN, AND E L E N A N L I T V I N E N K O Phase Dissolution Caused By Reimplantation Studied by Mossbaner Effect-VENKATESH K ASUNDt 650 657 Effect of Electron and Gamma-Ray Irradiation on the Chemical Composition and Atomic Distribution of Copper- and Iron-Based AHoys K G BINNATOV, YU L R O D I O N O V , A M D U L L A O M E K H R A B O V , AND I A L I - Z A D E Index 667 673 STP1046-EB/Apr 1990 Overview The Fourteenth International Symposium on Effects of Radiation on Materials was held on 27-30 June 1988 in Andover, MA This biennial symposium series commenced in 1956 and has served as a major international forum for the exchange and discussion of both the fundamental and technological aspects of behavioral changes in materials exposed to radiation environments The high level of participation at the latest symposium required four full days of conference sessions, and the peer-reviewed proceedings are being published in three volumes The papers from the first three days of the symposium appear in the two volumes of this ASTM Special Technical Publication (STP) 1046 Volume [ encompasses radiation damageinduced microstructures; point defect, solute, and gas atom effects; atomic-level measurement techniques; and applications of theory Volume II includes mechanical behavior, all papers dealing with pressure-vessel steels, breeder reactor components, dosimetry, and nuclear fuels The fourth day of the symposium was devoted to the single topic of reducedactivation materials, including austenitic, ferritic, and vanadium alloys, for future fusion reactors; these papers are being published in a companion volume: ASTM STP 1047, Reduced-Activation Materials for Fusion Reactors The first two sections of Volume I, Microstructures: Ferritics and Microstructures: Austenitics, deal with the effects of radiation on the structures of alloys being developed for high-dose environments, such as the first wall of a fusion reactor One notable theme is the profound influence of certain -minor" (that is, present in low concentration) but critical alloying elements, such as titanium, phosphorous, and others, primarily through the unique phases and microstructures they induce Examples are offered of fine dispersions of precipitates acting as distributed point defect and gas atom traps with the result that the growth of large voids or bubbles is inhibited Both neutron and charged-particle irradiations have been employed in these papers, while analytical transmission electron microscopy (TEM) seems to be the major technique of investigation In Gas Effects, a large number of papers (12) explore various aspects of what is probably the most pernicious nuclear transmutation product, helium If it is not hindered from collecting in bubbles at grain boundaries, the frequent result is helium embrittlement, which becomes a principal constraining factor for operation at high irradiation temperatures Among the papers presented are studies of helium embrittlement in ferritic alloys, in pure nickel and nickel-base alloys, a direct comparison between austenitic and martensitic steels, helium effects in the different regions of stainless steel welds, and bubble formation in pure copper and aluminum There are also fundamental studies of bubble formation for various inert gas species, and a technique paper offering a new way to introduce helium in mixedspectrum reactor experiments by the use of nickel-bearing foils adjacent to the specimens The section on Radiation-Induced Segregation or Phase Changes is an important one Copyright*1990 by ASTM International www.astm.org EFFECTS OF RADIATION ON MATERIALS because such radiation-induced modifications threaten to undo some of the hard-won gains in resistance to radiation damage obtained from increasingly sophisticated alloying An alloy matrix can be depleted of critical constituents, and if segregation or precipitation occurs at the grain boundaries, the material can be embrittled These papers explore the extent of segregation of such elements as phosphorous, silicon, and nickel in mainly austenitic or ferritic alloys, typically with the aid of surface analytical tools, such as Auger electron spectroscopy or secondary ion mass spectrometry (SIMS) Included are two papers dealing with the amorphization under irradiation of precipitates in zirconium alloys The papers in the section on Microstructural Modeling reflect the fact that the theory used to model radiation effects has reached a high level of sophistication These papers move beyond simple predictions of the dose or temperature dependence of void swelling to explore more fundamental defect behavior and the complex interactions between the various extended defects that are observed in irradiated materials Topics include: the direct influence of sinks, such as dislocations, precipitates and bubbles, on void swelling: dislocation loop formation; the formation of void and loop lattices: and possible void-dislocation interactions that could lead to swelling saturation Two papers that are of specific interest to the fusion materials community consider the influence of pulsed irradiation and the important problem of helium bubble formation at grain boundaries The five papers in the section on Fundamental Defect Behavior focus on the early stages of radiation damage The techniques used in the work reported here include internal friction, SIMS, and heavy-ion irradiation in a high-voltage electron microscope The materials ranged from austenitic alloys to the A 15 superconductors These results provide critical information about defect behavior and parameters that are required for modeling studies The papers discuss the nature of the displacement cascade, the small defect clusters that are formed as the cascade collapses, and the fraction of the originally-created defects that survive and diffuse out of the cascade, It is primarily these latter defects that lead to the observable effects of radiation The fate of these freely migrating defects and the helium that is produced by nuclear transmutation reactions is also discussed The last section in Volume I Special Measurement Techniques, comprises a number of specialized applications using effects from the domain of physics as novel tools for the probing of atomic-level processes The techniques employed are positron annihilation, internal friction, the Mossbauer effect, and nuclear gamma resonance Nicolas H Packan Oak Ridge National Laboratory, Oak Ridge, TN 37831: symposium chairman and coeditor Roger E Stoller Oak Ridge National Laboratory, Oak Ridge, TN 37831; symposium vice-chairman and coeditor Arvind S Kumar University of Missouri-Rolla, Rolla, MO 65401: symposium vice-chairman and coeditor 666 EFFECTS OF RADIATION ON MATERIALS Picraux, S T., Institute of Physics Conference Series, No 28 1976, p 183 Borders, J A, and Poate, J M., Physical Review B Vol 13, 1976, p 969 Sood, D K and Dearnaley, G., Institute of Physics Conference Series No 28, 1976, p 196 Gibb, T C., Principles of MOssbauer Spectroscopy, Chapman and Hall, London, 1976 Greenwood, N N and Gibb, T C., Mossbauer Spectroscopy, Chapman and Hall, London, 1971, p 90 [7] Asundi, V K., Joshi, M C., Deb, S K., Kulkarni, V N., Sood, D K., and Sundararaman, M., Radiation Effects, Vol 49, 1980, p 39 [8] Asundi, V K., Proceedings of Radiation Effects in Solids DAL Bhabha Institute of Fundamental Research, Bombay, India, 1983, p 397 [9] Preston, R S and Gerlach, R., Physical Review B Vol 1971, p 1519 [10] Preston, R S., Metalurgical Transactions, Vol 3, 1972 p 1831 [11] Stickels, C A and Bush, R H., Metalurgical Transactions Vol 2, 1971, p 2031 [12] Nasu, S., Gonser, U., Singu, P H., and Murakami, Y., Journal of Phys F (Metal Phys), Vol 4, L, 24, 1974 [131 Goldanski V I and Makarov, F E., in Chemical Application of MOssbauer Spectroscopy, V I Goldanski and R H Herber, Eds., Academic Press, New York 1968, pp 60-69 [14] Sawicka, B., "'Hyperfine Interactions of 'rFe Implanted in Solids." studied by CEMS, Report No 1030/PL Institute of Nuclear Physics Krakow, Poland, 1978 [15] Nelson, R S., Application orlon Beams to Metals, S T Picraux, E P Eer Nisse, and E L Vook, Eds., Plenum Press, New York, 1974, p 22l [16] Dearnaley, G., Freeman, J H., Nelson, R S., and Stephen, J., Ion Implantation (North Holland) Amsterdam, 1973 Appendix [17] Matsunami, N., Yamamura, Y., ltikawa, Y., Itoh, N., Kazumata, Y., Miyagawa, S., Morita, K., and Shimizu, R., Radiation Effects Letters, Vol 57, 1980, p 15 [18] Kelly, R., Nuclear Instruments and Methods, Vol 149, 1978, p 553 [19] Robinson, M T and Torrens, I M., Physical Review Vol 139, 1974, p 5008 [20] Gomez, G., Giraldez, G., Hertel, B., Ruble, M., and Wilkens, M., Application of Ion Beams to Metals, S T, Picraux, E P Eer Nisse, and F L Vook, Eds., Plenum Press, New York, 1974, p 469 [21] Jenkins, M L and Wilkens, M., Philosophical Magazine Vol 34, 1976, p 1155 [22] Window, B., Journal of Physics C Metal Phys., Suppl 3, 1970 [23] Sood, D K and Dearnaley, G., Institute of Physics Conference Series, No 28, 1976, p 196 [2} [3] [4] [5] [6] K G Binnatov, ~ Yu L R o d i o n o v , A m d u l l a O M e k h r a b o v , and I L A l i - Z a d e ~ Effect of Electron and Gamma-Ray Irradiation on the Chemical Composition and Atomic Distribution of Copper- and Iron-Based Alloys REFERENCE: Binnatov, K G., Rodionov, Yu L., Mekhrabov, A O., and Ali-Zade, I I., "Effect of Electron and Gamma-Ray Irradiation on the Chemical Composition and Atomic Distribution of Copper- and Iron-Based Alloys," Effects of Radiation on Materials: 14th In- ternational Symposium, Volume I, ASTM STP 1046, N H Packan, R E Stoller, and A S Kumar, Eds., American Society for Testing and Materials, Philadelphia, 1989, pp 667-672 ABSTRACT: This paper reports that the oxygen, hydrogen, carbon, nitrogen, and sulfur contents of steels and alloys can vary as a result of irradiation by electrons and gamma rays at comparatively low temperatures As this takes place, the materials can be either saturated with these elements, or these elements can be removed from the irradiated materials, depending on the irradiation medium Transformations are initiated as a result of radiation-stimulated oxygenation of copper-iron, iron-manganese, and iron-nickel alloys irradiated by gamma rays KEY WORDS: Steel 50, iron-sulfur, iron-chromium, iron-nickel, iron-manganese, copperiron, and nickel-hafnium alloys, electron and "y-ray irradiation, MOssbauer spectroscopy, Xray, redistribution, martensitic transformation Irradiation of materials by high energy particles is known to intensify crystallo-chemical transformations Specifically, corrosion and adsorption processes are sped up [1,2] and the diffusive mobility of impurities varies [3,4] O n e may suppose that during irradiation of metals some processes leading to changes in the chemical composition and to redistribution of impurities can take place However, note that only an insignificant n u m b e r of studies point to the possibility of a redistribution of impurities and a variation of the chemical composition under exposure to electron radiation [5-8] Conclusions concerning the redistribution of impurities in metals exposed to radiation were drawn by indirect methods, mainly on the basis of electrical resistance measurements At the same time, there were no data obtained directly, that is, by chemical analysis and structural methods Published reports fail to contain information on irradiation-induced alloy composition variations in carbon, oxygen, nitrogen, sulfur, hydrogen, and other elements In addition, there are essentially no reports on the part Department of Physics, Azerbaijan Civil Engineering Institute, Baku, Union of Soviet Socialist Republics Institute of Metallurgy and Physics of Metals, Bardin Central Research Institute of Ferrous Metallurgy, Moscow, Union of Soviet Socialist Republics Faculty of Physics, Azerbaijan State University, Baku, Union of Soviet Socialist Republics Copyright9 by ASTM lntcrnational www.astm.org 668 EFFECTS OF RADIATION ON MATERIALS played by composition changes under radiation on the course of phase transformations (precipitation, martensite transformations) The present report deals with the effect of irradiation by electrons (E, = to MeV) and gamma ray (E~ = 1.25 MeV) in different media and at different temperatures on the carbon, hydrogen, oxygen, nitrogen, and sulfur contents of alloys and steels This report also illustrates the effect of oxygenation of iron-manganese and iron-nickel alloys (under exposure to radiation) on the progress of martensite transformation Results Electron Irradiation o f Steel 50, Fe-O.OI % S and Fe-3%Cr Alloys A study was carried out of the effect of irradiation by electrons Ee = to MeV on the carbon and hydrogen contents in Steel 50 (0.45% carbon, 0.55% manganese, and 0.2% silicon) and of the sulfur content in the Fe-0.01%S alloy Specimens to 5-ram thick with diameters of to 10 mm were irradiated by electrons in a water stream (Steel 50) and in steam (Fe-0.01%S) The water temperature was not in excess of 100~ and the steam temperature was 500~ The total irradiation dose was d~ x 10=m -2 Upon exposure to radiation, the carbon content of Steel 50 specimens decreased by a factor of eight, whereas the hydrogen content showed a more than tenfold increase The sulfur content of Fe-0.01%S decreased to nearly one half A chemical analysis has shown a more than eight-fold increase in the nitrogen content of Fe-3%Cr on exposure to electron radiation in a nitrogen flux at a temperature of 200~ (Table 1) G a m m a - R a y Irradiation o f Fe-3%Cr, Cu-2%Fe and N i - l % H f Alloys The effect of gamma-ray irradiation (E, = 1.25 MeV), at 40 to 100~ on the variations in oxygen and hydrogen contents of steels and alloys was also studied The specimens under study (with thick of ~ to ram) were irradiated in media ensuring different partial pressures of oxygen: in evacuated quartz ampoules, as well as in ampoules containing powders of the lower oxides, nickel plus nickel oxide (NiO) and copper plus cuprous oxide (Cu20) Steel and alloy specimens of the following compositions were studied: Fe-3%Cr, Cu-2%Fe, and TABLE Variation of the content of nonmetallic elements in steels and alloys on exposure to radiation by electrons with energies Ec = to MeV and at an irradiation dose of + = x 10:2 rn-'- Content of Nonmetallic Elements, % Irradiated Material Element Steel 50 C Fe-0.01%S H S Fe-3%Cr N Irradiation Conditions (Medium, Temperature) irradiation in water, T ~ 100~ irradiation in steam, T ~ 500~ irradiation in a nitrogen flux, T ~ 200~ Before Irradiation After Irradiation 0.49 0.06 0.0008 0.0095 0.009 0.005 0.0087 0.074 BINNATOV ET AL ON ELECTRON AND GAMMA-RAY IRRADIATION 669 Ni-I%Hf The total dose absorbed by the specimens amounted to llY to 109 rad Chemical analysis of the Cu-2%Fe specimens irradiated in ampoules containing oxide powders has revealed an increase (by 37%) in the oxygen content (Table 2) When the Fe-3%Cr alloy is exposed to a 109 rad dose of ,/-ray radiation in water, its hydrogen content is doubled Ni-0.8%Hf alloy specimens subjected to a homogenizing annealing at 1000~ in a vacuum of 1.3 • 10-~Pa were exposed to gamma-ray irradiation in ampoules evacuated to a pressure of ~6.5 Pa and containing mixtures of nickel plus NiO powders An analysis of our data has shown that on irradiation the oxygen content of the specimens exhibits almost a fourfold increase Irradiation under a vacuum failed to bring about a substantial change in the oxygen content (Table 2) At the same time, no variations in the oxygen content were recorded with specimens irradiated in evacuated ampoules (low partial pressure of oxygen) Investigations have shown that under gamma-ray irradiation of alloys in oxygen-containing media the oxygen content of the alloys increases substantially In this case, the higher the partial pressure of oxygen in the irradiated medium, the greater the extent to which the material is oxygenated Thus, the data obtained show that irradiation of metals by electrons and gamma rays makes it possible to vary the impurity contents over a wide range at comparatively low temperatures The impurity contents can either increase or decrease depending on the irradiation conditions (medium, radiation type, irradiation temperature) The observed changes in the compositions of alloys under electron and gamma-quanta irradiation are likely to be due to an acceleration of the physico-chemical processes taking place at the interface between the metal and the surface-active medium In the radiation field an activation of the surface and an ionization of the atoms and molecules of the medium take place An interaction between the ions of the medium and the active sites can speed up the adsorption processes An impurity-concentration increase on the surface and an acceleration of diffusion processes under the effect of irradiation give rise to changes in the impurity contents of metals Effect of "v-Ray Irradiation on the Chemical Composition and Phase Transformations in Iron-Manganese Alloys In the initial state (hardened in water after one hour at IO00~ the alloys under study had a face-centered cubic structure (austenite) The initial temperature of the ' / ~ ~ and ' / ~ a transformation for the chosen iron-manganese alloys and that of the ' / ~ ot transformation for iron-nickel alloys were below room temperature, which made possible the treatment of the original austenite phase at relatively low temperatures Varying the phase composition substantially in the ordinary way is impossible, that is, as a result of heating the alloys in a vacuum (-