热连轧GH4169合金的点阵常数与蠕变性能

Lattice Parameters and Creep Properties of Tandem Hot Rolled GH4169 Alloy

通过对热连轧GH4169合金进行热处理、组织形貌观察、点阵常数测定及蠕变性能测试,研究热连轧GH4169合金的点阵常数与蠕变行为。结果表明:热连轧GH4169合金主要由γ基体、γ′和γ″相组成,经标准热处理后,合金中部分粒状γ′相重溶,且又在基体中析出扁平状γ″相;经X射线衍射分析表明,与热连轧合金相比,THR-ST-GH4169合金中γ基体、γ′和γ″相的点阵常数较小,但各相之间具有较大的晶格错配度,可有效阻碍位错运动,是合金具有较高蠕变抗力和较长蠕变寿命的重要因素之一;在蠕变期间,热连轧合金的主要变形机制为位错的双取向滑移,而在THR-ST-GH4169合金中,可形成形变孪晶和发生位错滑移。

The lattice parameters and creep behaviors of tandem hot tolled GH4169 alloy were investigated by means of heat treatment,microstructure observation,lattice parameter determination and creep property measurement.The results show that the microstructure of tandem hot tolled GH4169 alloy mainly consists ofγ,γ′andγ″phases.After standard heat treatment,some of granularγ′phase remelts,and separates out flat-likeγ″phase in the alloy.Comparing with THR-GH4169 alloy,by Xray analysis,theγ,γ′andγ″phases of THR-ST-GH4169 alloy possess smaller lattice parameters and larger lattice misfits among the phases,which may effectively restrain the dislocation movement,and is one of main important factors for the alloy possessing better creep resistance and longer creep life.During creep,the main deformation mechanism of THR-GH4169 alloy is that the dislocations with double orientations slip in the alloy.While the deformed twins and slipping dislocations may be activated in the THR-ST-GH4169 alloy.