Abstract: Type 1.4833 austenitic heat-resistant steel used in glass curing container storage tank of high level nuclear radioactive waste treatment has safety risks in long-term use at high temperature condition， and can not meet the needs of higher strength and better toughness and plasticity at high temperature condition of steel used in next generation storage tank. According to the application conditions of the storage tank， 0.12% Nb element is added to the original composition of YUS701 steel 25Cr-13Ni-2Si-0.8Mo-0.25N for the inner cover of the silicon steel ring cover annealing furnace ， appropriately reduce the content of C and Si elements. Electroslag remelting smelting process is adopted to control the deformation rate and temperature during forging and rolling. Finally， solid solution heat treatment at 1 150 ℃ is carried out to prepare the forgings of the improved YUS701 steel. The experimental results show that the improved YUS701 steel has good mechanical properties at room temperature. At 1 000 ℃， the yield strength exceeds 65 MPa and the tensile strength reaches about 100 MPa. After thermal cycle of simulated high temperature glass solid solution pouring， the impact absorption energy reaches more than 155 J， which can meet the performance requirements of the next generation of steel for storage tanks.

Key words: High-level Radioactive Waste, Glass Curing Body, Heat Resistant Steel, Improved YUS701 Steel

摘要： 核放射性废物处理中的高放废物玻璃固化容器储罐用1.4833型奥氏体耐热钢，在高温下长期使用存在安全风险，且无法满足下一代储罐用钢更高的高温强度、更好的高温韧塑性的需求。根据储罐的应用工况，在硅钢环形罩式退火炉内罩用钢YUS701原成分25Cr-13Ni-2Si-0.8Mo-0.25N基础上，添加0.12%的w［Nb］，适当降低C和Si含量，采用电渣重熔冶炼工艺，锻轧过程中控制变形速率和温度，最终在1 150 ℃进行固溶热处理，制备了改进型YUS701钢的实物锻件。试验结果表明，改进型YUS701钢具有良好的室温力学性能；1 000 ℃下屈服强度超过65 MPa，抗拉强度达到100 MPa左右；经过模拟高温玻璃固溶体浇注热循环后，冲击吸收功达到155 J，可满足下一代储罐用钢的性能需求。

关键词: 高放废, 玻璃固化体, 耐热钢, 改进型YUS701钢