工艺条件对镍基高温合金DD483单晶叶片中杂晶缺陷的影响

发布时间：2018-01-22 02:41

本文关键词： 高温合金 DD 定向凝固单晶叶片杂晶缺陷　出处：《铸造》2017年05期 　论文类型：期刊论文

【摘要】：利用Bridgman定向凝固工艺进行了高温合金DD483单晶叶片铸造试验,通过调整抽拉速度和使用不同型壳材料研究了工艺条件对杂晶缺陷的影响。结果表明,叶片中的杂晶缺陷一般出现在横截面突然扩大的缘板部位。铸件下部的外侧比内侧更易生成杂晶,但在上部则相反,即铸件内侧的杂晶缺陷更严重。在缘板部位降低抽拉速度能有效减少杂晶缺陷。在使用国产型壳时合金DD483叶片的单晶率非常低,但使用进口的纯刚玉型壳时叶片质量有明显提高,这说明型壳材料对单晶叶片中杂晶的形成有明显影响。
[Abstract]:The casting experiment of superalloy DD483 single crystal blade was carried out by Bridgman directional solidification process. The effects of process conditions on the heterocrystalline defects were studied by adjusting the drawing speed and using different shell materials. The heterocrystalline defects in the blade are usually found in the edge plate where the cross section suddenly expands. The lower side of the casting is more likely to form heterocrystals than the inner part, but the opposite is true in the upper part. In other words, the inner side of the casting has more serious heterocrystalline defects. Reducing the drawing speed at the edge plate can effectively reduce the heterocrystalline defects. The single crystal rate of the alloy DD483 blade is very low when the domestic mold shell is used. However, the quality of the blade is improved obviously when the imported pure corundum shell is used, which indicates that the shell material has an obvious influence on the formation of heterocrystals in the single crystal blade.
【作者单位】：东方电气集团东方汽轮机有限公司长寿命高温材料国家重点实验室;
【分类号】：TG132.3;TG245
【正文快照】： 表1合金DD483的化学成分Table1 1 Nominal composition of alloy DD483 wB/%高温合金叶片是航空发动机和重型燃气轮机最重要的核心部件,其晶体组织对使用性能有重要影响。随着铸造工艺的发展,叶片组织由原来的等轴晶改进为柱状晶,再优化为单晶组织,消除了晶界,使整个叶片只由

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