(1. 東北大學(xué) 材料與冶金學(xué)院，沈陽 110819；
2. 東北大學(xué) 材料電磁過程教育部重點(diǎn)實驗室，沈陽 110819)
摘 要: 采用Gleeble-1500D熱模擬機(jī)對GH4742高溫合金進(jìn)行高溫壓縮試驗，觀察該合金的金相組織和TEM顯微組織并進(jìn)行對比分析，研究該合金的動態(tài)再結(jié)晶行為。結(jié)果表明：小應(yīng)變速率、大變形程度及高變形溫度均促進(jìn)了該合金動態(tài)再結(jié)晶的進(jìn)行，第二相粒子通過影響位錯的運(yùn)動來影響合金的動態(tài)再結(jié)晶行為；晶界弓出機(jī)制是GH4742高溫合金動態(tài)再結(jié)晶的主要形核方式，部分孿晶通過疊加方式形核；通過對真應(yīng)力—真應(yīng)變曲線數(shù)據(jù)的計算擬合，構(gòu)建了GH4742高溫合金動態(tài)再結(jié)晶模型。
關(guān)鍵字: GH4742高溫合金；動態(tài)再結(jié)晶；熱壓縮；形核機(jī)制
（1. College of Materials and Metallurgy, Northeastern University, Shenyang 110819, China;
2. Key Lab of Electromagnetic Processing of Materials, Ministry of Education,
Northeastern University, Shenyang 110819, China）
Abstract:Hot compression tests of GH4742 superalloy were conducted on a Gleeble-1500D thermal simulating tester. Metallographs and TEM images were observed and compared, and dynamical recrystallization behavior was investigated. The results show that the dynamical recrystallization (DRX) of the alloy is promoted when the strain rate is small, the true strain is big and the temperature is high. The DRX behavior is affected by the second phase through which the movement of dislocation is influenced. The main nucleation mechanism of DRX in the present alloy is grain boundary bowing nucleation and the other nucleation mechanism is twin superposition nucleation. The DRX modeling of this alloy is established by means of mathematic fitting data based on true stress—true strain curves.
Key words: GH4742 superalloy; dynamical recrystallization; hot compression; nucleation mechanism
