径锻温度对GH4169合金棒材组织与性能的影响

Effect of radial forging temperature on microstructure and mechanical properties of GH4169 superalloy bar

研究了不同加热温度、终锻温度对GH4169合金Φ130mm径锻棒材组织和性能的影响。结果表明,加热温度和终锻温度过低时,棒材心部虽然获得了细于ASTM11级的晶粒,但表面甚至R/2处会因变形温度低于动态再结晶温度而残留部分原始拉长晶粒;同时δ相大量析出,不利于合金的综合性能。加热温度和终锻温度过高时,因原始晶粒在加热过程中过分长大,在变形过程中难以全部完成动态再结晶而残留部分原始拉长晶粒;同时δ相显著减少,合金的高温综合性能显著下降。在合适的加热温度和终锻温度下,棒材心部获得了均匀的10级晶粒,同时边缘获得了完全再结晶的11级晶粒,各部位δ相差异较小且基本呈颗粒状和短棒状在晶界均匀弥散分布,合金具有良好的低温、高温综合性能。

The effect of heating temperature and final forging temperature on microstructure and mechanical properties of GH4169 superalloy bar has been investigated in this paper.The results show that when the heating temperature and final forging temperature are too low,though the grain size in the center is finer than that of ASTM 11,incompletely recrystallized grains at surface or even at mid-radius are retained because the deformation temperature is lower than the dynamic recrystallization temperature.At this time,overmuch δ phase precipitates.This will be adverse to the alloy＇s mechanical properties.When the heating temperature and the radial forging temperature are too high,the original grains will overgrow and part of initial elongated grains will not be fully recrystallized,but stay.At the same time,the δ phase will be reduced and the alloy＇s comprehensive performance will also be reduced in the deformation process.Forged at a proper heating temperature and a final forging temperature,the grain size in the center of the bar is ASTM 10,and a completely recrystallized grain structure can reach ASTM 11 near the surface.The precipitation of δ phase in different positions of the bar varied slightly,granular or rod-like δ phase can be uniformly distributed at grain boundaries.At this time,the GH4169 alloy bars provide good mechanical properties at low and high temperatures.