Fracture toughness versus Charpy impact energy

6 Fracture toughness versus Charpy impact energy 

Another correlation in Sokolov and Nanstad (1999) between CVN transition temperature shifts and yield strength increases shows the relationship  

14 Comparisons of irradiation-induced shifts of fracture toughness and CVN energy for western-type RPV (a) weld metals and (b) base metals. As shown, the A74U and ATo (= T m) are essentially 1 1 for weld metals, but ATg is 1.16 x ATnj for base metals (Sokolov and Nanstad, 1999). 

The coefficient of 0.70 is the same as the value of 0.70 published in Odette et al. (1985) for AT41J and Actys- Moreover, Nanstad and Berggren (1993) published similar results specifically for low upper-shelf welds with coefficients ranging from 0.4-0.9 for seven different welds and an average value of 0.65, very close to the 0.70 value shown in Eq. 10.15. All such 

15 Comparison of CVN 41J transition temperature and the fracture toughness reference temperature To = Too) for the same western-type RPV materiais as in Fig. 10.14 (Sokoiov and Nanstad, 1999). 

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