Download or read book Effect of IVa and Va Elements on Void Formation in Neutron Irradiated 316 Stainless Steels written by S. Yamashita and published by . This book was released on 2000 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous electron irradiation study it was shown that additions of elements from the IVa and Va columns of the periodic table to 316L stainless steel could have a pronounced effect on its swelling resistance. The results suggested that vacancy binding was the main operative mechanism, increasing in strength with increasing size factor. In the current experiment these same alloys were irradiated with fast neutrons, but the influence of the size factor does not appear to be the only important mechanism. Whereas essentially precipitation was limited during electron irradiation, substantial precipitation occurred during neutron irradiation at lower displacement rates, overshadowing the effect of size factor on swelling. The addition of Hf and especially Zr, however, was particularly effective in suppressing swelling in both the electron and neutron cases, although the suppression mechanism in the neutron case appears to be a combination of both size effect and precipitation to alter the sink structure.
Download or read book Effects of Radiation on Materials written by Margaret L. Hamilton and published by ASTM International. This book was released on 2000 with total page 1266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dependence of Void Formation on Phase Stability in Neutron Irradiated Type 316 Stainless Steel written by HR. Brager and published by . This book was released on 1979 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The void swelling rate in Type 316 steel is dominated by the instantaneous composition of the austenite matrix rather than by the concurrent nature of the dislocation and void microstructure alone. This is the conclusion derived from a series of neutron-irradiation experiments designed to determine which microstructural components account for the variability of void development observed in this alloy in response to changes in composition, preirradiation treatment, and irradiation history. The attainment of steady-state swelling is thought to be related to the development of a saturation microstructure of precipitates and dislocations. The existence of a saturation state for dislocation microstructure has been confirmed, but this condition is reached at fluences substantially below the onset of steady-state swelling. Relative to a solution-annealed treatment, 20 percent cold working accelerates the approach to saturation of the dislocation microstructure; thus the delay of swelling by cold work cannot be rationalized simply in terms of the time or fluence dependence of dislocation density.
Download or read book Studies of Void Formation in Proton Irradiated Type 316 and Titanium Modified 316 Stainless Steels written by DW. Keefer and published by . This book was released on 1973 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Void formation was studied in annealed Type 316 stainless steel irradiated with 1-MeV protons at 400 C, 500 C, and 600 C (752, 932, and 1112 F) for amounts of damage up to 50 displacements per atom (dpa). Prior to irradiation, the samples were injected with about 5 atomic ppm helium to simulate the fast-reactor situation, where helium is generated by (n,?) reactions. The volume increase at each temperature, as determined by quantitative electron microscopy, varied exponentially with displacement damage and the exponent increased with temperature. Volume increases exceeding 20 percent were associated with 50 dpa at 500 C and 20 dpa at 600 C; no limits on volume increases were apparent at any temperature. Void number density decreased and average void size increased with increasing temperature for a constant damage. A titanium-modified 316 stainless steel developed a very inhomogeneous void distribution when proton irradiated at 600 C. However, the addition of titanium did not appear to diminish the volume increase at damages between 5 and 10 dpa, when compared with ordinary Type 316 stainless steel.
Download or read book Fusion Science and Technology written by and published by . This book was released on 2003 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Phase Stability on Void Swelling in P Ti Modified 316 Stainless Steels During Neutron Irradiation written by S. Ukai and published by . This book was released on 1999 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Commercially developed 20% cold-worked P,Ti-modified 316 stainless steel claddings were irradiated as fuel pins in C-type irradiation rigs of JOYO under typical fast reactor conditions. The microstructural changes of irradiated claddings at temperatures around 500 °C were extensively analyzed using transmission electron microscopy. Void formation is closely related with M6C and G-phase precipitates and concomitant phosphide dissolution beyond the fast neutron fluence of 15x1026 n/m2. Such phase instability in the fuel pin cladding during the fast reactor operation is caused by the radiation induced solute segregation, and it mainly interpreted in terms of varying system sink strength due to dislocation and precipitate changes.
Download or read book Effects of Microstructure on Swelling and Tensile Properties of Neutron Irradiated Types 316 and 405 Stainless Steels written by KR. Garr and published by . This book was released on 1973 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small-sheet tensile samples of Types 316 and 405 stainless steels were encapsulated together and irradiated in EBR-II at about 400 C (752 F) to a total fluence of 3.3 x 1022 n/cm2 with 2.3 x 1022 n/cm2 fast (E>0.1 MeV). A variety of microstructures was produced in each alloy prior to irradiation. In Type 316 stainless steel, swelling increased with the amount of carbide precipitation prior to irradiation, implying that carbon in solution impedes void formation. Cold-working 25 percent suppressed void formation. No swelling was observed in Type 405 stainless steel. Irradiation caused an increase in the yield and tensile strengths, and a decrease in ductility in all cases except the cold-worked Type 316 stainless steel. These latter samples showed a decrease in yield and tensile strengths and an increase in ductility due to the reversion of ? martensite to austenite.
Download or read book The Growth and Coalescence of Voids in Irradiated Metals written by Louis Kenneth Mansur and published by . This book was released on 1974 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Void Swelling and Microstructural Change in Neutron Irradiated Type 316 Stainless Steel written by M. Itoh and published by . This book was released on 1987 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microstructural observations were made on cold-worked Type 316 stainless steel following fast neutron irradiation to a peak neutron fluence of 1.3 x 1027 n/m2 (E > 0.1 MeV) at temperatures from 400 to 620°C. The results show that nickel depletion in the matrix after neutron irradiation is related to the formation of phosphides and void swelling. Phosphorus in solution retards not only the recovery of dislocations but also the development of nickel- and silicon-rich phases, and this results in suppressing nickel depletion in the matrix and an extension of the transient regime in void swelling. Phosphides are formed during the transient regime at temperatures from 490 to 570°C. After phosphides are formed, retardation effects on both dislocation recovery and the formation of nickel- and silicon-rich phases are lost, and this leads to the onset of void swelling.
Download or read book Void Formation in an Ion Bombarded Cold Worked Stainless Steel written by JL. Brimhall and published by . This book was released on 1975 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The void microstructure produced in a cold-worked Type 316 stainless steel by 5-MeV Ni++ ion bombardment has been studied. Within the temperature range 525 to 730°C, the void swelling shows a maximum at ~620°C. However, void formation extends to a temperature of 800°C. The results are consistent with those from neutron irradiation studies where the temperature shift is considered. The void swelling is dependent on (dose)mwhere m is in the range 2.5 to 3.3. A maximum swelling of 6 percent at 585°C and 125 displacements per atom were calculated. No saturation in the swelling was observed. Precipitates had a marked effect on the void distribution. The results agree reasonably well with results of similar studies using heavy ion bombardment.
Download or read book Void precipitate Association During Neutron Irradiation of Austenitic Stainless Steel written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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°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 of (DO heat) 316 at 500 to 650 C from 8.4 to 36 dpa in EBR-II. Cold work (CW) or helium preinjection delay void formation in EBR-II. Higher helium generation in HFIR also delays void formation at 500 to 640°C in SA 316 and CW DO heat 316. The delay persists in CW 316 at least to 61 dpa in HFIR, but abundant matrix and precipitate-associated voids form in SA after 47 dpa. In another heat of CW 316 (N-lot) irradiated in HFIR matrix and precipitate voids form readily after 22 to 44 dpa at 500 to 600°C.
Download or read book Void Formation in Cold Worked Type 316 Stainless Steel Irradiated with 1 MeV Protons written by DW. Keefer and published by . This book was released on 1975 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cold-worked Type 316 stainless steel was irradiated at 500and 600°C with 1-MeV protons. The dependence of void formation on displacement damage, irradiation temperature, and microstructure was studied by transmission electron microscopy. Cold working delays the onset of swelling and reduces it, via a reduction in void size, at both irradiation temperatures. Inhomogeneity in the cold-worked microstructure leads to inhomogeneity in the disposition of voids. Swelling at 600°C is greater than at 500°C; the voids are less numerous but larger at the higher temperature. No change in the cold-worked microstructure can be detected by transmission electron microscopy after 500°C irradiation to 23 displacements per atom. Irradiation to a comparable damage level at 600°C results in almost complete elimination of the cold-worked microstructure. Comparison of the results is made with data from reactor irradiation experiments.
Download or read book Void Formation in Cold worked Type 316 Stainless Steel Irradiated with 1 MeV Protons written by and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Neutron Irradiation on Types 316 and 321 and Sandvik 12R72 Stainless Steels written by KR. Garr and published by . This book was released on 1975 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specimens of Types 316 and 321 and Sandvik 12R72 stainless steels were irradiated in Experimental Breeder Reactor-II (EBR-II) to a fluence of 3.8 x 1022 neutrons (n)/cm2 (E > 0.1 MeV) at 500 and 600°C. Three different specimen configurations were used: small sheet tension specimens, small right circular cylinders for immersion-density measurements, and thin foils for transmission electron microscopy (TEM). The majority of the specimens were Type 316 stainless steel with differing metallurgical histories that can be classified as either cold rolled or solution annealed and aged. Specimens of the other alloys were in either a solution-annealed or solution-annealed and aged condition. Immersion density and TEM results showed that cold rolling prior to irradiation reduces the amount of swelling observed. For specimens in the annealed condition and irradiated at 500°C, there was essentially no difference in swelling for the three alloys. After irradiation at 600°C, however, TEM of a foil specimen of Type 321 stainless steel revealed very few voids with essentially no swelling. Irradiation-induced precipitates, whose size, type, and density varied with alloy, irradiation temperature, and previous treatment, were present in all alloys. The dislocation structure of the cold-worked specimens was essentially unchanged after the 500° irradiation but was significantly altered during the 600°C irradiation. Results of tension tests showed an increase in the yield strength and a decrease in the total elongation for specimens irradiated in an annealed condition, whereas specimens irradiated in the cold-rolled condition showed the reverse effect.
Download or read book Void Formation in Proton irradiated Stainless Steel written by D. W. Keefer and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Voids have been produced by 1.2-MeV proton irradiation at 500 degrees C in Type 316 stainless steel contain 2 atomic parts per million (appm) helium. The proton fluence was 6 x 1018 p/cm2. Observation of electron microscope foils, obtained at various positions along the proton pathlength, has shown that the average void diameter increased with increasing number of atom displacements, but that the void density remained constant. Calculated volume swelling ranged from 0.2 to 5%, depending on the number of displacements. In addition to voids, irradiation-produced dislocation loops and small precipitate particles on dislocations have been observed.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Second Phase Particles on Irradiation Swelling of Austenitic Alloys written by WK. Appleby and published by . This book was released on 1973 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are described from the investigation of swelling caused by fast-neutron-induced void formation in stainless steel fuel cladding and high-nickel alloys irradiated in fast flux (EBR-II) to fluences up to 7.3 x 1022 n/cm2, E > 0.1 MeV. Immersion density measurements of swelling gave results ranging from a volume increase of 10 percent in solution-annealed Type 347 stainless steel to a small densification in Inconel-625. Transmission electron microscopy investigations revealed that the extent of void formation in Types 316 and 347 stainless steels, Incoloy-800, and Hastelloy-X was related to the degree of intragranular precipitation (principally carbides), whereas the Ni3 Cb precipitation in Inconel-625 had apparently inhibited void formation altogether. It is concluded that precipitate particles can play a major role in determining the extent of void formation in austenitic alloys during neutron irradiation, and in the optimum morphology (a high concentration of closely spaced, small and possibly coherent particles) they offer promise of largely inhibiting void formation and swelling.
