【摘要】 自行设计开发了适合工业化生产高纯净,低偏析,无宏观缺陷铸锭的电渣重熔连续定向凝固技术(ESR-CDS)的设备和工艺,利用该技术成功制备了直径为150mm的René88DT合金定向凝固铸锭。采用XRD测试了定向凝固柱状晶的生长取向,结果表明,ESR-CDS René88DT铸锭柱状晶择优生长方向为<100>系晶向;ESR-CDS铸锭与传统ESR铸锭相比,枝晶组织生长方向保持一致,二次枝晶臂均匀细小,元素偏析程度低,且晶间一次析出相呈颗粒状,尺寸细小;等温热压缩实验结果表明,ESR-CDS René88DT合金热压缩试样在1100℃,0.05~0.1 s-1应变速率下可达到70%以上压缩变形量并获得均匀细小的动态再结晶组织;ESR-CDS René88DT合金铸锭经等温锻造制备出了170mm×73mm的饼坯件,锻压变形量超过70%,饼坯件除上下两端的变形死区外均发生了动态再结晶,晶粒尺寸约50μm。更多还原

【Abstract】 Electroslag remelting continuous directional solidification(ESR-CDS) technology was been developed in CISRI,it was a purity and free of solidification macro-defects remelting technology in industrial scale.René88DT superalloy ingot(150mm) was successfully produced by ESR-CDS.The columnar grain is grown parallel with the solidification direction along at <100> crystallographic orientation.Compared with the conventional ESR ingot,the ESR-CDS René88DT alloy ingot has finer pinetree structure,lower element segregation degree.The size of the dispersed granular carbides precipitated in grain boundary is smaller.The uniform complete dynamically recrystallized structure is achieved from the isothermal compression tests samples of ESR-CDS ingot under the condition of 1100℃,70% strain quantity and strain rate from 0.05s-1 to 0.1s-1.Isothermal forging was used to produce 170×73 pan billets with a 70% strain quantity.The dynamically recrystallized structure(uniform grain size 50μm) was generated in the billet except the deformed dead zones at top and bottom.更多还原