Impact behavior of Cr-W steels

Chromium-molybdenum ferritic (martensitic) steels are leading candidates for the structural components for fusion reactors. However, irradiation of steels containing molybdenum or niobium in a fusion environment will produce long-lived radioactive isotopes that will lead to difficult waste disposal problems. To alleviate the waste disposal problem, ferritic steels are being developed that are analogous to conventional Cr-Mo steels, but with molybdenum replaced by tungsten and niobium replaced by tantalum. Experimental steels containing 0.1% C, 2 1/4 to 12% Cr, 0 to 2% W, 0 or 0.25% V, and 0 or 0.07% Ta were produced. Charpy impact properties were determined. A 5Cr-2W-0.25V steel and a 9Cr-2W-0.25V-0.07Ta steel had the best impact properties. The impact properties of these two steels as well as those of a 9Cr-2W-0.25V and a 12Cr-2W-0.25V steel are described by the authors