摘要
本文在生产条件下,研究了不同约束性凝固参数对 DZ38G 合金定向结晶叶片的组织和力学性能影响。结果表明:在4mm/min 的抽拉速度下,可以获得柱晶平直,发散度小的定向结晶叶片。型壳和浇注温度过高会导致合金中 Cr 元素损耗率的增加,叶片显微疏松增多,组织粗大,合金力学性能降低。型壳温度在1500—1550℃,浇注温度为1500—1540℃时,可以获得满意的组织和较高的力学性能,所铸定向结晶叶片已通过台架长期试车的考验。
The effect of different solidification parameters on microstructures and me-chanical properties of the unidirectionally solidified superalloy DZ38G turbine blades wasstudied under commercial production conditions.Results indicate that blade of straightcolumnar grains with small divergent angles can be steadily produced at growth rate of4mm/min.It is found that over-raised pouring and mould tempetatures will cause severeloss of Cr content,serious microporosity and coarsening of the solidifed structrue,andconsequently,deterioration mechanical properties.It is shown that blades with satisfactorymicrostructures and novel mechanical properties can be made at pouring temperature of1500—1540℃ and mould temperature of 1500—1550℃.All blades cast have successfullyexperienced long-term test-trials.
基金
国家自然科学基金 9589014-03
关键词
凝固
合金
结晶
组织
性能
Ni基
unidirectional solidification
microstructure
mechanical property
