CORROSION-RESISTANT HALFNIUM AND PRODUCTION THEREOF

摘要

PURPOSE:To improve resistance to corrosion and hydrogen brittleness in the stage of producing an Hf rod to be used for a control rod of a nuclear reactor by orienting the <0001> axis of the hexagonal lattice positioned at least near the surface of the Hf rod in the direction perpendicular to the surface. CONSTITUTION:A cast ingot of Hf is hot-worked to a blank material and in succession the blank material is cold-rolled or warm-rolled at 380-460 deg.C and is further subjected to recrystallation annealing at about >=780 deg.C. The surface of the bar-shaped Hf is compression-worked by a method such as shot blasting or shot peening. The <0001> axis 2 of the Be hexagonal lattice positioned near the surface 3 of Hf as the control rod is oriented perpendicularly to the surface 3 at >=0.5 the fR value thereof by the above-mentioned treatment and heat treatment, by which the resistance to corrosion and hydrogen brittleness of the Hf control rod in the nuclear reactor is improved.