Abstract: The electrode of René88DT nickel allov ( % ： 0.02 ~ 0.05C. 15.5 ~ 16.5Cr, 3.8 ~4.2Mo, ≤0.20Ta, 12.5 ~13.5Co，0.6~1.0Nb, 0.025 ~0.050Zr, 3.5~3.9Ti, 2.0〜2.4AI, 0.006〜0.015B, 3.8〜4.2W, 0.005 ~ 0.010Ce) is melted by a 200 kg vacuum induction furnace and the Φ160 mm x 220 mm René88DT alloy ingot is melted by a 500 kg shielding atmosphere drawing-out ingot electroslag remelting furnace with continuously directional solidification process according to requirement of solidified structure to determine the melting speed during remelting by controlling secondary dendrite area space in ingot solidification, metal bath shape and depth and to get relative remelting parameters by thermal equilibrium calculation. Results show that the relative error between calculated total remelting time and real remelting time is only 4.5% , the bath is hallow lo get fine solidified structure with whole 〈100〉 direction columnar structure and secondary dendrite area space- 60 〜80 μm

摘要： René88DT镍基合金(%:0.02～0.05C、15.5～16.5Cr、3.8～4.2Mo、≤0.20Ta、12.5～13.5Co、0.6～1.0Nb、0.025～0.050Zr、3.5～3.9Ti、2.0～2.4Al、0.006～0.015B、3.8～4.2W、0.005～0.010Ce)母合金棒由200 kg真空感应炉熔炼,并按照凝固组织显微结构要求,通过控制铸锭凝固的二次枝晶间距和金属熔池形状及深度来确定重熔时熔化的速度,再通过热平衡计算得到相关的熔炼参数,由500 kg气氛保护抽锭式电渣重熔炉按连续定向凝固工艺熔炼出Φ160 mm×220 mm René88DT合金锭结果表明,计算重熔总时间与实际时间的误差仅为4.5%,熔池浅平,凝固组织均匀细小,获得了全〈100〉方向的柱状晶组织,二次枝晶间距为60～80μm。

关键词: 电渣重熔连续定向凝固, René88DT 基合金, 凝固组织控制, 工艺参数