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[en] The most important relations are assessed of refractoriness, creep plasticity and the character of damage at long-term creep exploitation of two alternatives of austenitic steel type AISI 316 with variable carbon and nitrogen levels. The single-axis tensile creep tests were performed in the temperature range 600 to 750 degC. Examples are shown of stress and temperature dependence of the time before fracture, of the temperature and time dependence of fracture ductility at creep, and the calculated values of creep tensile strength. For selected melt specimens, microhardness inside austenitic grains was assessed. An electron scanning microscope was used in the study of fracture surfaces. The conclusions were arrived at that the increase in creep plasticity due to restricted formation and proliferation of cavitation damage resulted in increased long-term refractoriness. For cavitation damage proliferation, the most significant factor is the distribution of intergranular precipitate, i.e., M23C6 and M6C particles and of intermetallic phases of sigma, chi and eta, and the strength of their interface to the matrix. (J.B.). 9 figs., 5 tabs., 41 refs
Journal
[en] Widespread intergranular stress corrosion cracking has occurred at welds in BWR piping systems. ASME Section XI requires that these service flaws be fully evaluated against fatigue crack growth. This paper discusses a data analysis model aimed at developing a correlation for available crack-growth data for stainless steel in PWR as well as BWR environments. Useful presentations of fatigue crack-growth data are obtained by plotting the time rate of crack growth for water environments as a function of the predicted time rate for air environments. The analysis suggests that fatigue crack growth in some stainless/water systems is a time-dependent, corrosion-related phenomenon. However, data for deoxygenated water environment do not indicate time-dependent characteristics. The data also indicate that the ASME Section XI Task Group recommendation for estimating corrosion fatigue crack-growth rates in austenitic piping materials may be unreasonable under certain loading conditions. Additional data are needed to confirm this conclusion. (author)
Journal
International Journal of Pressure Vessels and Piping; ISSN 0308-0161; 
; CODEN PRVPA; v. 31(1); p. 55-68
; CODEN PRVPA; v. 31(1); p. 55-68
[en] Reverse bending creep/fatigue tests have been performed on Type 316 steel at temperatures of 550 and 6000C for test durations of up to 12,000 h. It is shown that endurances obtained are comparable to those observed under push-pull conditions and that the introduction of a hold period can significantly reduce the endurance. Detailed fractography indicates that creep/fatigue in tension is more damaging than creep/fatigue in compression. The crack initiation behaviour is shown to be temperature dependent and may result from the combination of tensile and shear stresses, the relative importance of which will depend on the precise conditions of temperature, stress level and possibly microstructure. (author)
Journal
Fatigue and Fracture of Engineering Materials and Structures; ISSN 8756-758X; ; CODEN FFESE; v. 13(6); p. 551-561
; CODEN FFESE; v. 13(6); p. 551-561
[en] The phenomenological description of the material was a series of interrupted tensile loading with strain-rate change from quasi-static to dynamic. These data clearly showed that the material strength, although strain-rate sensitive, is not affected by the strain-rate history, indicating that a mechanical equation of state could be applied. The Bodner-Partom constitutive theory is first calibrated by the monotonic stress-strain curves collected at steady constant strain rates, then used to predict the response under various types of interrupted strain-rate change tests. (orig./HP)
Journal
[en] In order to produce Tritium by neutron irradiation in a fusion reactor the use of Li or of Lithium bearing materials is essential. The Breeding materials most commonly considered are liquid metals or alloys (Li, Pb-17Li) and ceramics (Li2O, LiAlO2, Li2SiO3, Li4SiO4, Li2ZrO3). The coolants are H2O, the liquid metals for alloys (self cooled concepts) or He. The structural materials envisaged comprise austenitic stainless steels (AISI 316, Cr-Mn steels), ferritic or martensitic steels (HT9, 1.4914). In this paper the main corrosion/compatibility effects are described and the results obtained critically reviewed. Special emphasis is placed on the compatibility between liquid metal or alloy and structural materials relevant to NET (Next European Torus). (author)
Source
European Federation of Corrosion, Brussels (Belgium); European Federation of Corrosion Publications; no. 1; 56 p; ISBN 0-901462-73-X; ; 1989; p. 35-46; The Institute of Metals; London (UK); EUROCORR '87: 1. meeting of the E.F.C. Working Party on nuclear corrosion; Frankfurt am Main (Germany, F.R.); 1987
; 1989; p. 35-46; The Institute of Metals; London (UK); EUROCORR '87: 1. meeting of the E.F.C. Working Party on nuclear corrosion; Frankfurt am Main (Germany, F.R.); 1987
[en] The present work has been carried out to evaluate the usefulness of the DC methods for corrosion monitoring, and to determine the correlation between results from extrapolation method of cathodic and/or anodic Tafel lines, polarization resistance method and the 3 point method. A comparison has been made between these results and by solution analysis using atomic absorption spectroscopy
Source
Iraq Atomic Energy Commission, Baghdad (Iraq). Nuclear Research Centre; Annual Report; (1989 issue); [200 p.]; 1989; p. 80; ISSN 1023-6295; ; Available from Information Center-Iraqi Atomic Energy Commission, Tuwaitha-Baghdad, P.O. Box 765, IRAQ
; Available from Information Center-Iraqi Atomic Energy Commission, Tuwaitha-Baghdad, P.O. Box 765, IRAQ
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