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in subjects: "Steels 360106* -- Metals & Alloys-- Radiation Effects"

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Interaction of xenon light with the surface of 304 stainless steel

Laser amplifier frames fabricated from Type 304 stainless steel are known to cause damage to glass lenses by ejecting particles which are deposited on the lenses. High energy pulses of xenon light interact with the steel surface to produce damage sites. Heat treatment and surface cleaning procedures greatly affect the surface stability of the steel and influence contamination generated by the steel. It is believed that inclusions and/or carbides play a role, and the size of damage sites observe… more

Date: February 14, 1978

Creator: Krenzer, R. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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An assessment of the effects of radiation on permanent magnet material in the ALS (Advanced Light Source) insertion devices

Electrons that are lost from the beam during normal operation of a synchrotron radiation source and during a beam dump at the end of a run produce both ionizing radiation and neutrons. This radiation has the potential for damaging sensitive materials, in particular those that need to be very close to the beam. The wigglers and undulators for the Advanced Light Source (ALS) at LBL will use magnetic materials such as the very high performance neodymium-iron-boron, which will be as close as 1 cm a… more

Date: August 1, 1989

Creator: Hassenzahl, W. V.; Jenkins, T. M.; Namito, Y.; Nelson, W. R. & Swanson, W. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Swelling in several commercial alloys irradiated to very high neutron fluence

Swelling values have been obtained from a set of commercial alloys irradiated in EBR-II to a peak fluence of 2.5 x 10/sup 23/ n/cm/sup 2/ (E > 0.1 MeV) or approx. 125 dpa covering the range 400 to 650/sup 0/C. The alloys can be ranked for swelling resistance from highest to lowest as follows: the martensitic and ferritic alloys, the niobium based alloys, the precipitation strengthened iron and nickel based alloys, the molybdenum alloys and the austenitic alloys.

Date: January 1, 1983

Creator: Gelles, D. S. & Pintler, J. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Comparison of the Relative Importance of Helium and Vacancy Accumulation in Void Nucleation

Void nucleation in irradiated austenitic stainless steels generally requires the presence of either residual or transmutant gases. Classical nucleation rates are much too low to account for the number of voids observed at temperatures greater than about 450/sup 0/C. An alternate path is generally believed to be responsible for void formation; viz. the growth of gas-stabilized bubbles until they reach a critical size beyond which further gas accumulation is not required to promote growth. Two li… more

Date: June 1, 1986

Creator: Stoller, R. E. & Odette, G. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Relationship between swelling and the shear modulus of irradiated metal

In three alloy systems, AISI 316, the Ni-Al binary system, and the Fe-Cr-Ni ternary system, a relationship exists between the shear modulus of the unirradiated alloys and the resultant swelling observed. An alloying addition which reduces the shear modulus will subsequently reduce the irradiation-induced swelling in a solid solution hardened alloy system. The reduction in swelling is thought to be associated with the void nucleation phase of the swelling phenomenon. Thus, relative high temperat… more

Date: February 1, 1979

Creator: Bates, J. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Small-angle neutron scattering from voids in neutron irradiated type 304 stainless steel. [E > 0. 1 MeV]

Preliminary small-angle neutron scattering results designed to investigate the structure of voids in neutron-irradiated polycrystalline annealed type 304 stainless steel were obtained. Specimens were subjected to irradiation at 400/sup 0/C to a fluence of 1.6 x 10/sup 23/ n/cm/sup 2/ (E > 0.1 MeV). Void interference effects were seen for voids having an average diameter of about 290 A. The distribution was ''gas-like''with an exclusion distance of 307 A. 1 figure, 1 table. (RWR)

Date: September 1, 1977

Creator: Child, H.R. & Spooner, S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Void-precipitate association during neutron irradiation of austenitic stainless steel

Microstructural data has recently become available on a single heat of 316 stainless steel irradiated in EBR-II and HFIR, over a wide range of irradiation temperature (55 to 750/sup 0/C), dose (7 to 75 dpa), and helium generation rate (0.5 to 55 at. ppM He/dpa). Extensive information on precipitate compositions and characteristics are included. The data reveal several important relationships between the development of voids and precipitation. Precipitate associated voids dominate the swelling o… more

Date: January 1, 1986

Creator: Pedraza, D. F. & Maziasz, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effect of temperature changes on swelling and creep of AISI 316

A number of previous publications have shown that the swelling of cold-worked AISI 316 is quite sensitive to changes in temperature which occur during irradiation. In this report those data are expanded and reanalyzed to show that the concurrent irradiation creep is also quite sensitive to changes in irradiation temperature. An explanation is advanced to explain this behavior in terms of the sensitivity to temperture history of the radiation-induced microchemical evolution of this steel. In par… more

Date: April 1, 1980

Creator: Garner, F. A.; Gilbert, E. R.; Gelles, D. S. & Foster, J. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Stress-enhanced swelling of metal during irradiation

Data are available which show that stress plays a major role in the development of radiation-induced void growth in AISI 316 and many other alloys. Earlier experiments came to the opposite conclusion and are shown to have investigated stress levels which inadvertantly cold-worked the material. Stress-affected swelling spans the entire temperature range in fast reactor irradiations and accelerates with increasing irradiatin temperature. It also appears to operate in all alloy starting conditions… more

Date: April 1, 1980

Creator: Garner, F. A.; Gilbert, E. R. & Porter, D. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Frank loop formation in irradiated metals in response to applied and internal stresses

The Frank loop and dislocation microstructures developed in three face-centered cubic alloys during fast reactor irradiation have been examined to determine the influence of applied and internally-generated stress on loop evolution. It is shown that anisotropic stresses generate a corresponding anisotropy of Frank loop populations on the four close-packed planes. The loop populations thus represent a microstructural record of the irradiation creep processes in action. The ease of interpreting t… more

Date: April 1, 1980

Creator: Gelles, D. S.; Garner, F. A. & Brager, H. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Temperature aspects of pulsed ion bombardment in an austenitic alloy

The influence of pulsed ion irradiation to a damage level of 10 dpa at temperatures from 843 to 1023/sup 0/K has been studied in a quaternary Fe-17Cr-17Ni-2.5Mo austenitic alloy. Pulsing periods of either 60 s on/60 s off or 1 s on/1 s off were used, together with continuous bombardment as a control. Helium (200 appM) was supplied either by simultaneous or room temperature preimplantation, or omitted. While most specimens experienced only 2 to 3/sup 0/K temperature fluctuations with the beam pu… more

Date: January 1, 1983

Creator: Packan, N. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of equilibrium and nonequilibrium segregation by x-ray microanalysis

X-ray microanalysis in an analytical electron microscope is a proven technique for the measurement of solute segregation in alloys. Solute segregation under equilibrium or nonequilibrium conditions can strongly influence material performance. X-ray microanalysis in an analytical electron microscope provides an alternative technique to measure grain boundary segregation, as well as segregation to other defects not accessible to Auger analysis. The utility of the technique is demonstrated by meas… more

Date: January 1, 1985

Creator: Kenik, E.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Swelling, microstructural development and helium effects in type 316 stainless steel irradiated in HFIR and EBR-II

This work examines the swelling and microstructural development of a single heat of 20%-cold-worked type 316 stainless steel irradiated to produce displacement damage and a high, continuous helium generation rate, in the High Flux Isotope Reactor (HFIR). Similar irradiation of the same heat of steel in the Experimental Breeder Reactor (EBR)-II is used as a base line for comparing displacement damage accompanying a very low continuous helium generation rate. At temperatures above and below the v… more

Date: January 1, 1981

Creator: Maziasz, P. J. & Grossbeck, M. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Strength and ductility of austenitic stainless steels after fast reactor irradiation. [645 to 740/sup 0/K from 0 to 0. 77 MeV]

Strength and ductility properties and stress-strain behavior of wrought 304 SS and 316 SS and weld-deposited 308 SS were correlated with a neutron irradiation damage parameter which incorporates effects of temperature (645 to 740/sup 0/K), exposure (10/sup 24/ to 10/sup 27/ n/m/sup 2/) and spectrum (average neutron energies from 0 to 0.77 MeV). The parameter reflects a greater spectral sensitivity for 304 SS than for the other two materials and predicts less damage as spectrum becomes softer or… more

Date: June 1, 1979

Creator: Blackburn, L.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Comparison of fracture behavior for low-swelling ferritic and austenitic alloys irradiated in the Fast Flux Test Facility (FFTF) to 180 DPA

Fracture toughness testing was conducted to investigate the radiation embrittlement of high-nickel superalloys, modified austenitic steels and ferritic steels. These materials have been experimentally proven to possess excellent resistance to void swelling after high neutron exposures. In addition to swelling resistance, post-irradiation fracture resistance is another important criterion for reactor material selection. By means of fracture mechanics techniques the fracture behavior of those hig… more

Date: February 1, 1992

Creator: Huang, F.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Strength and ductility of austenitic stainless steels irradiated in various fast reactor spectra

Radiation damage cross sections derived from mechanical property changes in stainless steels 304, 316, and 308L decrease as the fast reactor spectrum softens from a mean neutron energy of 0.75 MeV to 0.2 MeV. Spectral sensitivity of 304 is greater than that of 316 and 308L weld deposits. Damage cross sections are generally consistent with existing empirical or theoretical damage models but do not verify the applicability of any one particular theoretical model. (FS)

Date: January 1, 1979

Creator: Blackburn, L. D.; Ward, A. L.; Simons, R. L. & Lippincott, E. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mechanisms affecting swelling in alloys with precipitates

In alloys under irradiation many mechanisms exist that couple phase instability to cavity swelling. These are compounded with the more familiar mechanisms associated with point defect behavior and the evolution of microstructure. The mechanisms may be classified according to three modes of operation. Some affect cavity swelling directly by cavity-precipitate particle association, others operate indirectly by precipitate-induced changes in sinks other than cavities and finally there are mechanis… more

Date: January 1, 1980

Creator: Mansur, L.K.; Haynes, M.R. & Lee, E.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Spatial variation in void volume during charged particle bombardment: the effects of injected interstitials

Experimental observations of the void volume at several depths along the range of 4 MeV Ni ions in 316 stainless steel are reported. The specimens were first preconditioned by neutron irradiation at temperatures of 450 and 584/sup 0/C to fluences of approximately 8 x 10/sup 26/ n/m/sup -2/. The void volume after ion bombardment to 60 dpa at the peak damage depth is significantly lower at the peak damage depth than in the region between that and the free surface. The ratio of the step height to … more

Date: January 1, 1979

Creator: Lee, E.H.; Mansur, L.K. & Yoo, M.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effects of pulsed dual-ion irradiation of microstructural development

The effect of pulsed irradiation on the development of microstructure during Ni ion bombardment has been investigated in a simple austenitic alloy similar to type 316 stainless steel. Bombardment conditions were 10 dpa, 940 K, pulsing with equal on/off times of either 0.5 or 60 s, and the addition of 20 appM He/dpa to some specimens either by room temperature preimplantation or by dual-beam coimplantation. Particular care was taken to minimize thermal pulses from beam heating (to <2/sup 0/C). T… more

Date: January 1, 1981

Creator: Packan, N. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Develop of the climb induced glide concept to describee in-reactor creep of FCC materials

The Climb Induced Glide model (CIG) for irradiation creep is developed using a plastic flow law which has been successfully applied in the correlation of Type 316 stainless steel rupture data. This model is used to predict the stress and temperature dependence of irradiation creep and the transition from irradiation to thermal creep. The predictions of this model are compared and found to be qualitatively consistent with experimental data and microstructural information. This model allows predi… more

Date: May 1, 1979

Creator: Chin, B. A.; Straalsund, J. L. & Gilbert, E. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Precipitation and cavity formation in austenitic stainless steels during irradiation

Microstructural evolution in austenitic stainless steels subjected to displacement damage at high temperature is strongly influenced by the interactions between helium atoms and second phase particles. Cavity nucleation occurs by the trapping of helium at partially coherent particle-matrix interfaces. The recent precipitate point defect collector theory describes the more rapid growth of precipitate-attached cavities compared to matrix cavities where the precipitate-matrix interface collects po… more

Date: January 1, 1981

Creator: Lee, E.H.; Rowcliffe, A.F. & Mansur, L.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Bias factors for radiation creep, growth and swelling

Central to the present concepts of the origin of the radiation-induced creep, growth and swelling phenomena is the relative interaction of interstitials and vacancies with various sinks. Radiation-induced climb of dislocations, which figures in many theories of radiation creep and growth, requires the absorption of an excess of either vacancies or interstitials. On the other hand, radiation swelling requires the absorption of an excess of vacancies to affect void growth. These relative preferen… more

Date: January 1, 1979

Creator: Nichols, F.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Influence of injected helium on the phase instability of ion-irradiated stainless steel

The influence of helium injection on phase instability under ion irradiation was studied for two modified 316 stainless steel alloys. Helium is required to nucleate voids in both alloys, though both exhibit phase instability without helium. The injected helium promotes associated growth of voids with precipitates. At low simultaneous helium injection rates 0 to 4 appm He/1 dpa), little or no effect on the precipitation process occurs. As the injection rate increases to 20 appm He/dpa, an increa… more

Date: January 1, 1980

Creator: Kenik, E.A. & Lee, E.H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Heavy Section Steel Technology Program. Irradiation effects on the fracture toughness of heavy section pressure vessel steels. Quarterly progress report for period ending August 31, 1975

The recovery by postirradiation annealing of the irradiation produced shift in the fracture toughness transition of A533-B was investigated. Irradiation embrittlement was reduced by 40% after annealing at 600/sup 0/F for material that had been irradiated to approximately 2 x 10/sup 19/ n/cm/sup 2/ at 550/sup 0/F.

Date: September 1, 1975

Creator: Williams, J.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department