摘要
为探究不同峰值温度的多次钎焊热循环对GH4169合金组织与性能的影响规律,以GH4169合金为研究对象,系统研究了钎焊热循环工艺对GH4169合金的析出相、晶粒尺寸、拉伸性能及持久性能的影响。结果表明:δ相的析出量随热循环温度的升高呈下降趋势,形态由针状转变为棒状后再转变为颗粒状;在970~1010℃范围内,晶粒尺寸变化不大,而当温度升高至1020℃以上时,晶粒显著长大。抗拉强度和硬度均随热循环温度的升高先增加后降低,并在1010℃时达到峰值,这主要得益于该温度下适量δ相溶解与γ″、γ′强化相的充分析出,而晶粒尺寸并未发生明显粗化;室温冲击韧性在不同的热循环范围具有不同的变化趋势,970~990℃范围内随温度升高而降低,这是由δ相的部分形态由针状转变为棒状所导致;990~1010℃范围内随着温度升高而增加,是由δ相溶解,无强化相析出带消失所导致,而继续增加热循环温度导致冲击韧性下降则是由于晶粒尺寸长大。持久寿命随热循环温度的升高先缩短后延长,在990~1000℃范围内达到最低点,这是由δ相的部分形态由针状转变为棒状,促进微孔形核,降低合金的抗蠕变能力所致。当温度进一步升高至1020℃以上时,γ″强化相大量析出并辅以晶粒显著长大,合金的蠕变性能得以显著改善,但针状δ相含量大幅度降低导致缺口敏感性增强。综合考虑力学性能与缺口敏感性,建议在1010℃左右进行钎焊热循环,可获得较为平衡的强度与持久性能;若服役环境对缺口敏感性要求较高,可选择970~980℃的热循环温度,以降低蠕变失效风险。
To delve into the impacts of multiple brazing thermal cycles at varying peak temperatures on the microstructure and properties of GH4169 alloy,this study conducted a comprehensive examination of how brazing thermal cycle processes influence the precipitates,grain size,tensile properties,and stress-rupture properties of the alloy.The findings reveal that as the thermal cycle temperature rises,the quantity ofδ-phase precipitation diminishes,and its morphology undergoes a transformation from needle-like to rodlike and eventually to granular.Within the temperature range of 970-1010℃,the grain size experiences minimal alteration.However,when the temperature surpasses 1020℃,significant grain growth occurs.Both tensile strength and hardness initially ascend and then descend with an increase in the thermal cycle temperature,reaching their peak values at 1010℃.This phenomenon is mainly attributed to the dissolution of an appropriate amount ofδphase and the complete precipitation ofγ″andγ′strengthening phases at this temperature,while the grain size does not show significant coarsening.The room-temperature impact toughness demonstrates distinct trends across different thermal cycle ranges.In the 970-990℃range,it decreases with rising temperature due to the partial transformation of theδ-phase morphology from needlelike to rod-like.In the 990-1010℃range,it increases with temperature as theδphase dissolves and the strengthening-phase-free zone vanishes.Nevertheless,a further increase in the thermal cycle temperature leads to a reduction in toughness because of grain growth.The stress-rupture life initially declines and then rises with an increase in the thermal cycle temperature,hitting its lowest point in the 990-1000℃range.This is caused by the partial transformation of theδ-phase morphology from needle-like to rod-like,which promotes microvoid nucleation and reduces the alloy′s creep resistance.When the temperature further rises above 1020℃,the extensive precipitation ofγ″strengthening phases,along with significant grain growth,substantially enhances the alloy′s creep performance.However,the substantial decrease in the needle-likeδ-phase content results in increased notch sensitivity.Taking into account both mechanical properties and notch sensitivity,it is recommended to employ brazing thermal cycles around 1010℃to achieve a wellbalanced combination of strength and stress-rupture performance.For service environments with higher notch sensitivity requirements,a thermal cycle temperature in the range of 970-980℃can be selected to minimize the risks of creep failure.
作者
王诗洋
刘士伟
武震东
梅寒
张财伟
徐彦强
董佳鹏
郭伟
孙元
张洪宇
WANG Shiyang;LIU Shiwei;WU Zhendong;MEI Han;ZHANG Caiwei;XU Yanqiang;DONG Jiapeng;GUO Wei;SUN Yuan;ZHANG Hongyu(High Temperature Structural Materials Research Department,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;Air Military Representative Office in Liaoyang,Shenyang 110000,China;AECC Shenyang Liming Aero Engine Co.,Ltd.,Shenyang 110043,China;School of Aeronautic Science and Engineering,Beihang University,Beijing 100083,China)
出处
《材料工程》
北大核心
2026年第3期113-121,共9页
Journal of Materials Engineering
基金
辽宁省重点研发计划项目(2024JH2/102400043)
国家自然科学基金(52201054)
辽宁省自然科学基金(2023010404-JH3/101,2023010697-JH3/107)。
