论文部分内容阅读
使用扫描电镜观察了某发动机一级导向器叶片铸造裂纹。发现导致裂纹的主要原因是沿晶界连续分布的碳化物,其弱化了晶界,并阻断了枝晶间的补缩通道,促进了叶片疏松的形成。使用同炉K441母合金在叶片浇注的过程中进行了不同工艺的熔体处理实验。然后使用X射线衍射和扫描电镜分析了叶片相含量和组织的变化,发现合适的熔体处理可以改善碳化物的形态,从而减少铸件的热裂倾向。
Scanning electron microscope (SEM) was used to observe the casting crack of the first stage guide vane. It is found that the main reason leading to cracks is the carbides continuously distributed along the grain boundaries, which weaken the grain boundaries and block the channel of the shrinkage between the dendrites and promote the formation of loose leaves. Using the same furnace K441 master alloy in the process of blade casting process of different melt processing experiments. Then X-ray diffraction and scanning electron microscopy were used to analyze the change of the leaf phase content and microstructure. It was found that proper melt treatment can improve the morphology of the carbide and thus reduce the hot cracking tendency of the casting.