孙长明,吴保平,韩凤奎,吴剑涛,李俊涛

• 1:钢铁研究总院高温材料研究所

摘要(Abstract)：

通过调整铸造工艺参数,研究了K4648合金的组织结构与工艺参数变化之间的关系,进而获得铸造工艺对热疲劳性能的影响规律。对合金经90020℃循环条件下热疲劳试验后的试样表面形貌进行观察分析,研究了晶粒尺寸及晶界结构对合金热疲劳性能的作用机制。研究结果表明:随着浇注温度的升高,合金的晶粒平均尺寸增大,而模壳温度的提高对合金的晶粒尺寸影响不大,采用沙箱+保温棉造型方式可细化合金晶粒。热疲劳主裂纹从V形缺口处萌生,裂纹以穿晶模式扩展。通过调整浇注工艺细化晶粒,并使得晶界结构呈锯齿态,可降低裂纹扩展速率,提升合金的热疲劳性能。

关键词(KeyWords)： K4648合金;热疲劳;晶界;晶粒尺寸

Abstract:

Keywords:

基金项目(Foundation):

作者(Author): 孙长明,吴保平,韩凤奎,吴剑涛,李俊涛

DOI: 10.13289/j.issn.1009-6264.2016-X286

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