Effect of rhenium and osmium on mechanical properties of a 9Cr-2W-0.25V-0.07Ta-0.1C steel

The nuclear transmutation of tungsten to rhenium and osmium in a tungsten-c ontaining steel irradiated in a fission or fusion reactor will change the c hemical composition of the steel. To determine the possible consequences of such compositional changes on the mechanical properties, tensile and Charp y impact properties were measured on five 9Cr-2W-0.25V-0.07Ta-0.1C steels t hat contained different amounts of rhenium, osmium, and tungsten. The mecha nical properties changes caused by these changes in composition were minor. Observations were also made on the effect of carbon concentration. The eff ect of carbon on tensile behavior was minor, but there was a large effect o n Charpy properties. Several of the steels showed little effect of temperin g temperature on the Charpy transition temperature, a behavior that was ten tatively attributed to the low silicon and/or manganese concentration of th e experimental steels. (C) 2000 Elsevier Science B.V. All rights reserved.