CAJ | 학술논문

采用Gleeble-1500D热模拟机对GH4742高温合金进行高温压缩试验，观察该合金的金相组织和TEM显微组织并进行对比分析，研究该合金的动态再结晶行为。结果表明：小应变速率、大变形程度及高变形温度均促进了该合金动态再结晶的进行，第二相粒子通过影响位错的运动来影响合金的动态再结晶行为；晶界弓出机制是GH4742高温合金动态再结晶的主要形核方式，部分孪晶通过叠加方式形核；通过对真应力-真应变曲线数据的计算拟合，构建了GH4742高温合金动态再结晶模型。
채용Gleeble-1500D열모의궤대GH4742고온합금진행고온압축시험，관찰해합금적금상조직화TEM현미조직병진행대비분석，연구해합금적동태재결정행위。결과표명：소응변속솔、대변형정도급고변형온도균촉진료해합금동태재결정적진행，제이상입자통과영향위착적운동래영향합금적동태재결정행위；정계궁출궤제시GH4742고온합금동태재결정적주요형핵방식，부분련정통과첩가방식형핵；통과대진응력-진응변곡선수거적계산의합，구건료GH4742고온합금동태재결정모형。
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.