196,110 research outputs found
Virgilio, Eneide.
No full textTraduzione di M. Ramous, Introduzione di G. B. Conte, Commento di G. Baldo, Venezia, Marsili
Per Mario Ramous traduttore classico
No full textConsiderazioni storiche e stilistiche sull'opera traduttiva di Mario Ramou
Influence of isothermal aging on secondary phases precipitation and toughness of a duplex stainless steel SAF 2205
No full textIn this paper the results of secondary phases determination in a SAF 2205 duplex steel, heat treated at 780, 850 and 900 °C for 10-40 min, are presented. χ-phase is the first phase to precipitate at all the temperatures, followed by σ-phase. The main drop of toughness is related to very low contents of χ-phase and σ-phase. Hardness is not a sensitive parameter to low amounts of secondary phases
The phase stability in Cr-Ni and Cr-Mn duplex stainless steels
No full textthe formation of secondary phases during isothermal treatments in the range 750-1000 °C and continuous cooling in 2205, 2507, 2304, and 2101 duplex stainless steels have been investigated. For all the steels herein considered, the Thermocalc calculations indicate the sigma and chi-phase precipitation which is confirmed by the experimental results only for the 2205 and 2507 grades. On the contrary, the secondary phases are very rarely observed after both isothermal aging (up to 750 h) and/or continuous cooling tests in the 2304 and 2101 Cr-Mn grades. This behavior could be justified by the different ferrite and austenite phase stability in the four grades, in the same temperature range of the sigma and chi precipitation, because these differences affect the dangerous phases precipitation mechanism and kineti
Precipitazione di fasi secondarie in un acciaio duplex 2205 trattato isotermicamente (Precipitation of secondary phases of 2205 duplex stainless steel after isothermal
No full textA duplex stainless steel (DSS) containing nominally 22Cr, 5Ni, 3.2Mo and 1.5Mn has been investigated for secondary phases precipitation, after ageing at 780, 850 and 900°C. Selective etching with different reagents, OM and SEM-BSE have been used to quantify ferrite, austenite and secondary phases. A critical discussion of different metallographic techniques (use of OM and/or SEM-BSE) applied to measure intermetallic content is presented, including an attempt to distinguish chi and sigma. The chemical composition of the phases has been determined by means of EDS, the effects on mechanical properties have been studied with a hardness test. The hardness increases with holding time for all temperatures. The rate of secondary phases increases with the holding time. The 850°C treatment is the most effective for increasing hardness and secondary phase precipitation. The SEM-BSE method seems to be more reliable than OM for measuring the secondary phase contents and for identifying chi and sigm
Precipitation of secondary phases in super duplex stainless steel ZERON100 isothermally aged.
No full textIn the present paper the results of secondary phases determination and quantification in ZERON100 duplex steel, heat treated at 850-1000°C for 180-2400 s, are presented. During the isothermal heat treatments, at 850°C, the χ phase is the only phase to precipitate at α/γ boundaries and triple points, while at 900 and 950°C, χ phase is the first phase to precipitate after 180 s, followed by σ phase 300 s later. At all the temperatures the total amount of secondary phases is ∼3% after ,600 s aging. (17 refs.
Precipitazione di fasi secondarie in acciai Lean Duplex a seguito di trattamenti isotermici
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