Effects of sodium environment on the mechanical properties of Fe-2 1/4Cr-1Mo steel [report]

O,K. Chopra
1983 unpublished
Mechanical property data on isothermally annealed, thermally aged, and sodium-exposed Fe-2 l/4Cr-1Mo steel are analyzed to evaluate the influence of the sodium environment as well as the effects of the microstructural and compositional changes that occur in the steel during long-term exposure to sodium. Correlations are developed to predict the environmental effects on tensile, creep, fatigue, and creep-fatigue properties of Fe-2 l/4Cr-!Mo steel in sodium. The results indicate that at
more » ... e that at temperatures <823 K (550*C), degradation of mechanical properties is essentially due to thermal aging. Loss of carbon from the steel reduces both the tensile and creep-rupture strength, but has little or no effect on the fatigue properties. The cyclic properties of Fe-2 l/4Cr-lMo steel in sodium are superior to those in a-fr. The creepfatigue behavior in sodium is significantly different from that in an air environment. The creep-fatigue data are analyzed using the interactive damage rate equations to predict the time-dependent fatigue behavior of isothermally annealed Fe-2 l/4Cr-lMo steel in sodium. The objective of this paper is to establish quantitatively the effects of the low-oxygen environment and decartjrization during long-term sodium exposure on the mechanical properties of isothermally annealed Fe-2 l/4Cr-lMo steel. Data obtained on annealed, thermally aged, and sodium-exposed material are analyzed to evaluate the environmental effects on tensile, creep, fatigue, and creep-fatigue properties.
doi:10.2172/5400591 fatcat:q6gjcng4sve53n3twcniupxwme