METALLURGICAL ASPECTS OF POSSIBILITY OF 9-12-PERCENT CHROMIUM STEEL APPLICATION AS A STRUCTURAL MATERIAL FOR FIRST WALL AND BLANKET OF FUSION-REACTORS

Steels containing 9-12% Cr are considered to be candidate structural m aterials for the first wall and blanket of a fusion reactor at the ope ration temperature up to 650 degrees C. The optimal structure, phase c omposition and the specific chemical composition of the steels ensure their high heat resistance, yield strength and ductility as well as ad equate thermophysical properties. The susceptibility of chromium steel s for low temperature irradiation embrittlement can be influenced by c hanging their structural state via alloying, heat treatment and method of melting. Steels having a uniform martensite structure are less sus ceptible to irradiation conditions and have more stable tensile proper ties as compared to steels having delta-ferrite in their structures.