RADIATION-RESISTANT CHROMIUM STEEL FOR FAST REACTORS Russian patent published in 2004 - IPC

FIELD: metallurgy; nuclear power engineering. SUBSTANCE: radiation-resistant chromium steel proposed for cans of fuel assemblies, sleeves of control and protection systems, fuel element claddings, and associated pieces of equipment has composition of ingredients in following proportion, mass percent: carbon, 0.09-0.15; silicon, 0.25-0.50; manganese, 0.2-1.0; chromium, 11.0-13.5; nickel, 0.05-0.30; molybdenum, 1.4-2.0; vanadium, 0.10-0.30; niobium, 0.15-0.50; boron, 0.004-0.015; calcium, 0.001-0.05; iron and associated impurities, the rest. Steel can also have in its composition 0.10-0.20 mass percent of zirconium, maximum 0.07 mass percent of nitrogen, maximum 0.014 mass percent of sulfur, and maximum 0.025 mass percent of phosphor. Total content of carbon and nitrogen is 0.15-0.20 mass percent and that of boron and phosphor is not over 0.030 mass percent; ratio of total content of vanadium, niobium, and zirconium to that of carbon and nitrogen is 2 to 6. Fuel burn-up is 10 to 15 % of millimass unit and service life of control and protection system is raised from 260 to 700 effective days due to increased resistance to shape change of parts. EFFECT: enhanced strength and plasticity of steel. 8 cl, 6 dwg, 1 tbl