Re对单晶高温合金高温高应力持久性能的影响

Effects of Re on stress rupture properties of single crystal superalloys at elevated temperature and high stress

基于DD6合金成分,调整合金Re与Cr含量,浇注5种不同Re含量单晶高温合金。通过对合金在1 038℃,248 MPa持久性能的测试及对合金断裂组织扫描、透射电镜观察与分析,探讨了Re对单晶高温合金高温高应力持久性能的影响。结果表明:在高温高应力条件下,随合金中Re含量的单独增加,合金高温高应力持久寿命提高,而单位质量Re元素的强化作用减弱;合金Cr含量对合金高温高应力持久寿命有显著影响,Re含量增加的同时适当降低合金Cr含量,可使合金获得较高的持久寿命。

The effects of Re on stress rupture properties of high refractory content single crystal Ni-base superalloys at elevated temperature and high stress were investigated. Based on the compositions of DD6 alloy, five experimental single crystal superalloys containing varied levels of Re and Cr were produced. High temperature stress rupture tests were carried out at 1038 C with an engineering stress of 248 MPa. The stress rupture life is found to be remarkably improved with Re addition but the strengthening effect of Re is depressed with increasing Re content only, and alloys can achieve rather longer stress rupture life by increasing Re content and decreasing Cr content at the same time.