| 温度对GH4169合金蠕变行为及机制的影响 |
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| 引用本文： | 高圣勇,葛树欣,杨选宏,王倩,包燕平. 温度对GH4169合金蠕变行为及机制的影响[J]. 工程科学学报, 2023, 45(2): 301-309. DOI: 10.13374/j.issn2095-9389.2021.08.27.005 |
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| 作者姓名： | 高圣勇 葛树欣 杨选宏 王倩 包燕平 |
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| 作者单位： | 1.北京科技大学钢铁冶金新技术国家重点实验室，北京 100083 |
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| 基金项目： | 2020年河北省重点研究资助项目（JMRH2020-27）；河北省省级科技计划资助项目（20311007D） |
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| 摘 要： | 在研究了温度对镍基高温合金GH4169蠕变行为及机制的影响基础之上，分析了其断口形貌和蠕变断裂机理。实验结果表明，随着蠕变温度的升高，GH4169合金的稳态蠕变速率逐渐升高，蠕变寿命显著降低，即该合金有极强的温度敏感性。蠕变过程中，γ″相长大聚集，并向δ相转变，随着蠕变温度的升高，γ″相向δ相转变速度加快，晶内的γ″相数量减少，δ相所占体积增加，尺寸增大，次生裂纹数量减少，尺寸减小。当蠕变温度为650 ℃时，断口中存在较多亮白色撕裂棱，韧窝尺寸大小不一，有少量析出物和碳化物；当温度提高到670 ℃时，韧窝尺寸减小，以浅韧窝为主，且出现解理面；当温度提高到690 ℃时，只存在少量韧窝，且δ相的数量显著增多，出现解理台阶，断裂方式为解理断裂或准解理断裂。
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| 关 键 词： | GH4169镍基高温合金 蠕变性能 δ相 γ″相 微观结构 |
| 收稿时间： | 2021-08-27 |
Effect of temperature on the creep behavior and mechanism of GH4169 alloy |
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| Affiliation: | 1.National Key Laboratory of Steel Metallurgy New Technology, Beijing University of Science and Technology, Beijing 100083, China2.School of Materials Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China3.AVIC Shangda Superalloy Materials Co., Ltd, Xingtai 054800, China4.AVIC Xi’an Aircraft Industry Group Co. Ltd, Xi’an 710089, China |
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| Abstract: | GH4169, a precipitation-strengthened nickel-based superalloy, has been extensively used in structural applications in temperatures up to 650 ℃ because of its high-temperature strength, long-term stability, thermal fatigue, creep resistance, corrosion resistance, weldability, oxidation resistance, and easiness to forging. Although GH4169 has been introduced for many years, it is still widely used in many applications, especially under a high-temperature environment such as the turbine engine and the turbine disk part of advanced aero-engines, spacecraft, and gas turbines. Its microstructure mainly contains five phases: γ, γ″ (Ni3Nb), γ′ (Ni3AlTi), δ (Ni3Nb), and MC carbides. The main strengthening phase of the GH4169 alloy is the γ″ phase, which is metastable, and its phase transformation to the δ phase occurs when exposed at temperatures above 650 ℃. This paper studied the effect of temperature on the creep behavior and mechanism of the nickel-based superalloy GH4169 and analyzed its fracture morphology and creep rupture mechanism. Experimental results showed that the steady creep rate of the GH4169 alloy increased, and the creep life of the GH4169 alloy decreased significantly with the increase of the creep temperature, i.e., the alloy had strong temperature sensitivity. During the creep process, the γ" phase grew, aggregated, and transformed to the δ phase. With the increase of the creep temperature, the transition of the γ″ phase to the δ phase was faster, the amount of γ″ phases in the crystal decreased, the size and volume of the δ phase increased, and the number and size of secondary cracks decreased. When the creep temperature was 650 ℃, more bright white tearing edges in the fracture appeared, the dimple size was different, and there were a small amount of precipitates and carbonization. When the temperature increased to 670 ℃, the dimple size decreased, with mainly shallow dimples and cleavage surfaces appearing. When the temperature increased to 690 ℃, there were only a few dimples and cleavage steps, and the number of δ phases increased significantly, which meant that the fracture mode was cleavage fracture or quasi-cleavage fracture. |
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