【摘要】 用不同凝固速度下定向凝固和定向凝固加快淬的方法研究了Ｐ，Ｚｒ，Ｂ对定向凝固ＩＮ７３８合金组织和偏析的影响发现随磷含量的增加，合金固液两相区宽度及温度区间显著增加；凝固前沿低熔点液相区增大；树枝晶组织发达，二次晶变细、变多；固液界面表面积增加。发现只加Ｐ与同时加Ｐ，Ｚｒ合金的溶质原子偏析规律有差异。Ｐ，Ｚｒ，Ｂ促进合金中（γ＋γ′）共晶形成，在其前沿有（γ＋硼化物）共晶析出。更多还原

【Abstract】 Effects of P, Zr and B on the solidification behaviour of directionally solidified IN738 superalloy have been studied by the methods of directional solidification plus rapid quenching and at various solidification rates. With the increase of P content in the alloy, the breadth of solid-liquid biphase region and temperature interval may be obviously enlarged;the residual liquid phase in interdendritic region increased; the dendritic structure developed;the secondary dendritic arms become more numerous and thinner, and the interfacial area between solid and liquid extended. The solute segregation of the alloy is different between addition of only P and of P together with Zr to the alloy. With alloy containing P, Zr and B, the formation of (γ+γ’) entectic and precipitation of (γ+boride) eutectic in its front may be promoted.更多还原