摘要
在温度1000~1060℃、应变速率0.1~10 s^(-1)下,对GH4080A合金进行了总变形量一致的单、双道次热模拟压缩试验。分析了合金不同道次流变行为,揭示了双道次变形导致热处理晶粒异常长大机制。结果表明:在单、双道次热压缩变形中,随变形温度升高和应变速率减小,GH4080A合金流变应力减小。但由于双道次变形停留发生了亚动态再结晶,第二道次流变应力总是略低于第一道次。通过应力变化计算了合金不同变形参数下的亚动态再结晶率,发现升高变形温度、提高应变速率都会增大亚动态再结晶软化率;而亚动态再结晶软化率越高,热处理后出现晶粒异常长大的概率越大。这主要与双道次间歇期组织内γ’强化相减少、不能有效钉扎晶界迁移有关。
Under the condition of temperature 1000-1060 ℃ and strain rate of 0.1-10 s^(-1), GH4080A alloy was subjected to a single and double pass thermal compression simulation test with the same total deformation amount. The thermal deformation behavior of the alloy in different passes was analyzed and calculated. The softening rate of sub-dynamic recrystallization under different thermal deformation parameters was founded to be related to the abnormal growth mechanism of heat-treated grains. The results show that the flow stress of GH4080A alloy decreases with the increase of deformation temperature and the decrease of strain rate during the single and double pass compression. The second pass compression stress is always slightly lower than the first pass stress. The increase of deformation temperature and strain rate lead to a higher softening rate of sub-dynamic recrystallization calculated through the variation of flow stress. The probability of abnormal growth of grains in the microstructure after heat treatment is almost constant with the softening rate of sub-dynamic recrystallization. When the softening rate of sub-dynamic recrystallization is high, there is a higher probability of abnormal grain growth in the microstructure of the alloy after heat treatment. This is mainly because the γ’ phase decreases in the microstructure during the deformation interval of the double pass thermal deformation.
作者
李凯
林莺莺
陈由红
王轶博
赵张龙
LI Kai;LIN Yingying;CHEN Youhong;WANG Yibo;ZHAO Zhanglong(Research and Engineering Technology Center of Plastic Forming,Beijing Institute of Aeronautical Materials,Beijing 100095,China;School of Material,Northwestern Polytechnic University,Xi'an 710072,China)
出处
《热加工工艺》
北大核心
2022年第24期30-33,40,共5页
Hot Working Technology
