论文部分内容阅读
通过对等温锻造和热连轧工艺制备的GH4169合金进行蠕变性能测试和组织形貌观察,研究制备工艺对GH4169合金组织结构及蠕变行为的影响。结果表明:在热连轧期间,合金发生孪晶变形和位错滑移;与等温锻造相比,热连轧合金中的高密度位错具有形变强化的作用,可提高合金的蠕变抗力。在蠕变期间,等温锻造合金仅发生孪晶变形,而热连轧合金的变形机制是孪晶和位错滑移,其中,合金在热连轧期间形成的高密度位错可诱发蠕变位错发生单取向或多取向滑移,可减缓应力集中,抑制或延缓裂纹在晶界处萌生是使该合金具有较长蠕变寿命的主要原因。蠕变后期,裂纹在与应力轴垂直的晶界处萌生,并沿晶界扩展、发生解理断裂是2种工艺制备合金的蠕变断裂机制。
The creep property and microstructure of GH4169 alloy prepared by isothermal forging and hot tandem rolling process were observed and the effect of preparation process on microstructure and creep behavior of GH4169 alloy was studied. The results show that the twinning deformation and dislocation slip occur during the hot rolling. Compared with the isothermal forging, the high density dislocations in the hot rolling alloy have the effect of strengthening the deformation and increasing the creep resistance of the alloy. During the creep, only twin deformation occurred in the isothermal forging alloy, while the deformation mechanism of the hot-rolled alloy was twins and dislocation slip, in which the high-density dislocations formed during hot rolling of the alloy induced the creep position The occurrence of unidirectional or multi-orientation slippage can reduce the stress concentration and restrain or delay the initiation of cracks at grain boundaries, which is the main reason for the long creep life of the alloy. In the late stage of creep, the crack initiated in the grain boundary perpendicular to the stress axis and extended along the grain boundary. The cleavage fracture was the creep rupture mechanism of the two kinds of alloys.