摘要
为了研究直接时效对热连轧GH4169合金组织结构及蠕变行为的影响,通过对热连轧合金直接时效、蠕变性能测试和组织形貌观察,分析了热连轧直接时效合金的组织结构与蠕变变形及断裂机制.结果表明:经直接时效热连轧合金组织由细小晶粒构成,且具有明显的孪晶特征,细小γ″相在合金中弥散析出;在蠕变期间,合金的变形特征是形成三取向孪晶变形和位错在基体中发生单双取向滑移、起形变强化作用、使合金具有较高蠕变抗力和较长蠕变寿命的原因;随着蠕变的进行,位错逐渐在晶界处堆积并产生应力集中,促使裂纹在晶界处萌生;在蠕变后期,合金的蠕变断裂机制表现为裂纹沿晶界扩展并发生断裂.
In order to investigate the influence of direct aging treatment on the microstructure and creep behavior of hot continuous rolled（HCR） GH4169 superalloy,the microstructure,creep deformation and fracture mechanisms of the superalloy after direct aging treatment were analyzed through the direct aging treatment,creep property test and microstructural observation of the superalloy.The results show that the microstructure of the superalloy after direct aging treatment consists of fine grains with obvious twins.Moreover,the fine γ″ phase dispersedly precipitates in the superalloy.During the creep,the deformation characteristics of the superalloy are the twinnig deformation with three different orientations and the dislocation slip in the matrix with single or double orientations,which will offer the deformation strengthening effect and lead to the higher creep resistance and the longer creep life.As the creep deformation goes along,the dislocations gradually pile up at the grain boundaries and the stress concentration occurs,which will cause the initiation of cracks at the grain boundaries.At the later stage of creep deformation,the fracture mechanisn of the superalloy is that the cracks propagate along the grain boundaries and the creep fracture occurs.
出处
《沈阳工业大学学报》
EI
CAS
2011年第6期649-654,共6页
Journal of Shenyang University of Technology
基金
国家自然科学基金资助项目(50634030)
关键词
GH4169合金
热连轧
直接时效
微观组织
蠕变
断裂机制
GH4169 superalloy
hot continuous rolling
direct aging
microstructure
creep
fracture mechanism
