(北京航空材料研究院，北京 100095)
摘 要: 通過(guò)拉伸試驗(yàn)和微觀組織觀察等方法對(duì)經(jīng)過(guò)不同溫度和時(shí)間模擬高溫服役環(huán)境熱暴露處理后7050-T7452鍛件的室溫拉伸性能以及合金金相組織、析出相的變化情況進(jìn)行系統(tǒng)研究。結(jié)果表明：7050-T7452鍛件在100~ 175 ℃下熱暴露處理后，合金的強(qiáng)度隨熱暴露溫度的提高和時(shí)間的延長(zhǎng)而降低，伸長(zhǎng)率隨之增加；當(dāng)熱暴露溫度超過(guò)125 ℃后，變化更為明顯；隨熱暴露溫度和時(shí)間的變化，合金的晶粒尺寸以及再結(jié)晶程度沒(méi)有明顯改變；當(dāng)熱暴露溫度≤125 ℃時(shí)，合金晶粒內(nèi)部析出相的尺寸和種類沒(méi)有明顯變化；隨熱暴露時(shí)間的增加，晶界無(wú)析出帶的寬度略有增寬；當(dāng)熱暴露溫度超過(guò)125 ℃時(shí)，合金晶內(nèi)的析出相隨溫度以及熱暴露時(shí)間的增加而迅速粗化，η相的體積分?jǐn)?shù)增加，晶界無(wú)析出帶加寬，合金的強(qiáng)度明顯下降。
關(guān)鍵字: 7050-T7452鍛件；高溫服役環(huán)境；熱暴露處理；顯微組織；析出相；拉伸性能
（Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract:The evolution of microstructure and properties of 7050-T7452 alloy forging simulation in high temperature service environment for different times and temperatures was studied by tensile test and transmission electron microscopy．The results show that the strength of 7050-T7452 alloy forging decreases with the thermal exposed time and temperature increasing in the range of 100-175 ℃, however, the elongation increases. The change of strength is obvious when the exposed temperature is higher than 125 ℃, and the change of grain size and recrystallization is not obvious. When the exposed temperature is lower than 125 ℃, the sizes and species of precipitates do not change obviously. The width of precipitate-free zones (PFZs) increases a little with the exposed time increasing. When the exposed temperature is higher than 125 ℃, the precipitates in matrix are coarser with the exposed temperature and time increasing. Meanwhile, the precipitate size and width of PFZs increase obviously, and the dominant precipitate is η phase. The strength of alloy decreases visibly in this period.
Key words: 7050-T7452 alloy forging; high temperature service environment; thermal exposed treatment; microstructure; precipitate; tensile properties
