共查询到19条相似文献,搜索用时 62 毫秒
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高温长期时效对钴高温合金GH605组织与性能的影响 总被引:1,自引:1,他引:0
研究了长期时效处理对钴基高温合金GH605组织与性能的影响。结果表明,815℃长期时效过程中,随时效时间的延长,析出碳化物(主要是M6C)逐渐增多,而且时效500h后发现有少量针状或棒状Laves相析出。高温塑性,尤其是室温塑性的下降与碳化物过分粗化以及脆性Laves相的析出并增多有关,但这两个因素对于室温拉伸强度及高温持久寿命的影响较小。为了使合金塑性得到恢复,可以采用重新固溶处理的措施。 相似文献
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GH169合金高温长期时效后的组织性能变化 总被引:3,自引:1,他引:2
对GH169合金进行了600℃、1000h和650℃、6000h的长期时效。600℃时效1000h后,合金的组织、性能未见明显变化;在650℃时效至6000h后,合金组织发生变化:γ″相粗化、大量γ″相转化成δ相、晶界两侧的γ″相贫化区加宽。同时合金的拉伸性能在650℃、1000h时效后也随着时效时间的延长而下降,其持久寿命下降更快。 相似文献
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The need for nickel-base powder metallurgy (PM) superalloy turbine discs is becoming increasingly evi dent. With the eventual aim of improving thrust-to-weight ratio of aeroengines for power generation, well integration of significantly high strength, high damage tolerance and high-temperature capability would be reasonably required. An advanced PM superalloy, which was designed for applications up to 815- 8 5 0 ℃, was experimentally investigated. Emphasis was primarily put on microstructure and mechanical properties. The results indicated the measured phases in the sample were composed of γ,γ', MC, and Ma B2. With uniform coarse grain microstruc ture (ASTM 5-6), the sample appeared to exhibit overwhelming superiority over the prior art materials FGH95, FGH96, FGH97 and FGH98. The dominant embodiments consisted of high tensile strength (Rm = 1000 MPa and Rp0.2 800 MPa at 850℃), strong creep resistance (ξp 0.12% at 815 ℃/400 MPa/50 h), and considerable stressrupture life (τ=457.4 h at 815 ℃/450 MPa). The technical practicability of applications up to 815-850 ℃ of this alloy was conclusively proved. 相似文献
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采用SEM、EDS和Thermo-Calc热力学计算等方法,分析了镍基高温合金GH4133B在不同时效时间和时效温度下的组织演化规律。从而对改善合金的服役性能提供理论依据。试验结果表明:随着时效时间的延长和时效温度的升高,晶粒尺寸无变化,碳化物种类、分布和数量变化均不明显;长期时效后的γ′强化相的尺寸较时效前都有所增加,尤其800℃时长大最明显,形状也由球形颗粒变为方形颗粒并出现一定的取向性;800℃时效500 h以上或更长时间后,合金中开始出现少量针状的η相在晶界及一次碳化物附近析出。 相似文献
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Effect of Cooling Rate on Microstructure and Mechanical Properties of K465 Superalloy 总被引:2,自引:0,他引:2
K465 superalloy, as a material for production of turbine nozzle, shows high mechanical properties as well as microstructure stability in critical and severe service conditions. The alloy gains its appropriate microstructure and strength through solid solution strengthening mechanism. Heat treatment parameters such as: time and temperature of homogenization, partial solution and aging temperatures, and cooling rate from solid solution affect the microstructure of the alloy. Among these parameters cooling rate from solid solution is the most effective. Therefore, in this study the effect of cooling rate on microstructure and mechanical properties (tensile and stress properties) were investigated. For this purpose, three different cooling rates were applied on the cast K465 specimens after solution treatment at 1210℃ for 4 h. Microstructures of the specimens then were studied using optical and electron microscopy. Also, tensile tests were performed at room temperature and stress rupture tests were performed under the condition of 975℃ and 230 MPa. It was found out that with increasing cooling rate the size of the γ' precipitates decreases and the mechanical properties of specimens increases. Also, it was shown that the shape and volume fraction of primary γ' particles are largely influenced by the cooling rate following solution treatment at 1210℃ for 4 h. 相似文献
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