Abstract: Austenitic stainless steel for nuclear power plant reactor internals is extremely strict in terms of purity， grain size， corrosion resistance and mechanical properties， and stable quality materials are crucial to the safe operation of nuclear power plants. By setting a reasonable chemical composition（mass fraction） target value for 316 stainless steel， namely w［C］0. 045%，w［N］0. 06%，w［Cr］17. 00%，w［Mo］2. 50%，w［Ni］12. 50，w［Mn］1. 80%； Three dimen⁃ sional pre-melting and remelting smelting is used to improve the purity of molten steel， and low melting speed is set to re⁃ duce smelting segregation. Combine forging and rolling； control the consolidation insulation time according to material specifications and accurately control the cold drawing deformation at 2 mm. The austenitic stainless steel SA-479 316（N- 60-6） cold-drawn bar for reactor internals has been successfully developed. Its non-metallic inclusions A， B， C and D are all ≤1. 0 grade， grain size reaches grade 5， intergranular corrosion qualified， room temperature yield strength 479-545 MPa， high temperature tensile strength 515-575 MPa at 350 ℃， meeting the requirements for the use of cold drawn bars for in-stack components.

Key words: Key Words：Reactor Internals, Austenitic Stainless Steel, Cold Drawn Bars, Mechanical Property

摘要： 核电站堆内构件用奥氏体不锈钢对材料的纯净度、晶粒度、耐腐蚀性及力学性能要求极其严格，质量稳定 的材料对核电站的安全运行至关重要。通过对 316 不锈钢设计合理的化学成分（质量分数）（/%：0. 045C、0. 06N、 17. 00Cr、2. 50Mo、12. 50Ni、1. 80Mn）；采用三元预熔渣重熔冶炼提升钢液纯净度，低熔速减少冶炼偏析；锻造+轧制 联合开坯；依据材料规格控制固溶保温时间；精确控制冷拉变形量 2 mm。成功研制出堆内构件用奥氏体不锈钢 SA-479 316（N-60-6）冷拉棒材。其非金属夹杂物A、B、C、D类粗系、细系单项均≤1. 0级，晶粒度达到5级，晶间腐蚀 合格，室温拉伸屈服强度479~545 MPa，350 ℃高温拉伸强度515~575 MPa，满足堆内构件用冷拉棒材使用要求。

关键词: 堆内构件, 奥氏体不锈钢, 冷拉棒材, 力学性能