PRODUCTION OF BORON-CONTAINING STAINLESS STEEL FOR BASKET IN SPENT NUCLEAR FUEL CASK HAVING EXCELLENT DUCTILITY, TOUGHNESS AND CORROSION RESISTANCE.

摘要

PURPOSE:To improve the ductility of the B-contg. austenitic stainless steel by packing gaseous nitrogen atomized powder having a specific compsn. into a mild steel can and subjecting the powder to an HIP treatment under specific temp. and pressure conditions. CONSTITUTION:The gaseous nitrogen atomized powder of =50mum contg. B, C, Si, Cr, Ni, Mo, N and O in a specific range is packed into the specific mild steel can and after the can is vacuum sealed, the powder is subjected to the HIP treatment under the specific temp. and pressure conditions. The boride of the B-contg. austenitic stainless steel to be used for a fuel basket material, etc., of a cask for transportation and storage of spent nuclear fuel is formed to finer grains, by which the ductility, toughness and corrosion resistance of the steel sheet are improved and edge cracks at the time of hot rolling are entirely eliminated. The efficient removal of the mild steel parts at the time of refining of the steel plate is possible.