Concurrent Annealing Of Vacancy-Type And Interstitial-Type Damage In Neutron Irradiated Stainless Steel

2000 ◽  
Vol 650 ◽  
Author(s):  
E. P. Simonen ◽  
D. J. Edwards ◽  
S. M. Bruemmer

ABSTRACTAnalysis of the effect of annealing on change in void and loop size distributions provided insights that complement microstructural characterization using transmission electron microscopy (TEM). The predictions of concurrent vacancy-type and interstitial-type damage annealing are applied to measurements in neutron-irradiated austenitic stainless steels. Irradiation at 330°C produces void and loop microstructures for which the measured annealing response is in accord with predictions. Irradiation at 275° produces only Frank loop microstructure for which the annealing response cannot be predicted from measured microstructures. The model predictions are based on an assumed vacancy source not detected using TEM. The measured loop microstructure is typically reported to be interstitial in character but this analysis suggests that a significant component of the loop population is vacancy-type damage based on defect inventory and kinetic arguments.

Author(s):  
E. Johnson ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
E. Gerritsen ◽  
J. Politiek ◽  
...  

Cross-sectional transmission electron microscopy (XTEM) has been used to study the microstructure of noble gas implanted austenitic stainless steels, and in particular to analyse the depth distribution of implantation induced martensite in relation to the general radiation damage distribution.Large discs of low-austenitic stainless steels have been ion implanted with noble gases to fluences in the range l.1020 - 1.1021 m-2. Samples of the implanted discs for cross-sectional transmission electron microscopy (XTEM) were made by electroplating the implanted surface with a 3 mm thick layer of nickel, cutting 3 mm discs from the interface and electropolishing the discs to perforation using a Struers TENUPOL immersion jet apparatus.In samples implanted with low fluences (1-1020 m-2) the implantation zone consists of a heavily damaged top layer containing a dense distribution of microscopic noble gas inclusions, which are visible in defocusing phase contrast. The inclusions are ∽ 3-5 nm in diameter, and the smallest inclusions contain noble gas in the solid phase.


2011 ◽  
Vol 194-196 ◽  
pp. 32-37 ◽  
Author(s):  
Feng Shi ◽  
Yang Qi ◽  
Chun Ming Liu

Precipitation behaviors of Fe-18Cr-12Mn-0.48N and Fe-18Cr-18Mn-0.43N high-nitrogen austenitic stainless steels isothermally aged at 800°C were investigated by using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that precipitation both display discontinuous cellular way and the major precipitates are both M2N phases accompanied by scattered M23C6 phases at grain boundary in the experimental steels. Increment of Mn content can not change the precipitation way and precipitation type. Increment of Mn content makes M2N precipitates obviously increase and increment of Mn and C contents makes M23C6 precipitates increase.


2010 ◽  
Vol 16 (6) ◽  
pp. 662-669 ◽  
Author(s):  
S. Simões ◽  
F. Viana ◽  
A.S. Ramos ◽  
M.T. Vieira ◽  
M.F. Vieira

AbstractReactive multilayer thin films that undergo highly exothermic reactions are attractive choices for applications in ignition, propulsion, and joining systems. Ni/Al reactive multilayer thin films were deposited by dc magnetron sputtering with a period of 14 nm. The microstructure of the as-deposited and heat-treated Ni/Al multilayers was studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) in plan view and in cross section. The cross-section samples for TEM and STEM were prepared by focused ion beam lift-out technique. TEM analysis indicates that the as-deposited samples were composed of Ni and Al. High-resolution TEM images reveal the presence of NiAl in small localized regions. Microstructural characterization shows that heat treating at 450 and 700°C transforms the Ni/Al multilayered structure into equiaxed NiAl fine grains.


1999 ◽  
Vol 5 (S2) ◽  
pp. 848-849
Author(s):  
J.S. Luo ◽  
D.P. Abraham

Stainless steel-zirconium (SS-Zr) alloys have been developed as waste forms to immobilize and retain fission products generated during the electrometallurgical treatment of spent nuclear fuel. The baseline waste form is a stainless steel-15 wt.% zirconium (SS-15Zr) alloy, which is prepared by melting appropriate amount of Type 316 stainless steel (SS316) and high purity zirconium. As zirconium has very low solubility in iron, the addition of zirconium to SS316 results in the formation of ZrFe2 -type Laves intermetallic phases. The corrosion behavior of stainless steel has been widely studied; however, the corrosion behavior of the Zr-based-intermetallic has not been previously investigated. In this paper, we present a microstructural characterization of the corrosion layer formed on the Zr-intermetallic phase using energy-filtering transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS).Specimens of SS-15Zr alloy, crushed to 75 to 150 μm sizes, were immersed in 90°C deionized water for a period of two years.


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