凝固偏析对GH4706合金热变形及动态再结晶行为的影响  

Effect of solidification segregation on hot deformation and dynamic recrystallization behavior of GH4706 alloy

作　　者：王岩龙 刘杨[1] 王磊[1] 王雨晗 宋秀[1] 段然 王冲 黄烁 Wang Yanlong;Liu Yang;Wang Lei;Wang Yuhan;Song Xiu;Duan Ran;Wang Chong;Huang Shuo(Key Lab for Anisotropy and Texture of Materials,Northeastern University,Shenyang 110819,Liaoning,China;Bejing Steel Research Gaona Technology Co.,Ltd.,Bejing 100081,China)

机构地区：[1]东北大学材料各向异性与织构教育部重点实验室,沈阳110819 [2]北京钢研高纳科技股份有限公司,北京100081

出　　处：《特钢技术》2025年第1期5-14,共10页Special Steel Technology

基　　金：国家重点研发计划项目(2022YFB3705101);国家重点研发计划项目(2022YFB3705102);国家自然科学基金项目(52371096)。

摘　　要：本研究通过系统的热模拟实验,深入对比分析了GH4706合金偏析区与非偏析区的流变行为、本构关系、热加工图以及微观组织演变规律。经摩擦修正后的实验数据表明,材料的流变应力随着温度的升高和应变速率的降低呈现出显著的下降趋势。通过计算得出非偏析区和偏析区的热激活能分别为412.689kJ/mol和430.557kJ/mol。研究重点基于动态材料模型(DMM),构建了不同应变条件下非偏析区及偏析区的热加工图,热加工图显示,非偏析区的加工性能明显优于偏析区。利用热加工图结合微观组织,确定了最佳热加工工艺参数:1050~1100℃/0.001~0.01s^(-1)。研究还发现偏析区具有更低的晶粒平均取向差角和较高的局部应变,其在低温高应变速率下易发生动态再结晶,但随着温度的升高和应变速率的降低,动态再结晶晶粒明显粗化。本研究成果为优化大尺寸GH4706合金的热加工工艺提供了重要的理论指导,对提升大型GH4706合金构件的性能和服役可靠性具有显著的工程应用价值。This study conducted a systematic thermal simulation experiment to comparatively analyze the flow behavior,constitutive relationships,processing maps,and microstructural evolution of segregated and non-segregated regions in GH4706 alloy.The friction-corrected experimental data revealed a significant decrease in flow stress with increasing temperature and decreasing strain rate.The calculated thermal activation energies for non-segregated and segregated regions were 412.689 kJ/mol and 430.557 kJ/mol,respectively.Focusing on the Dynamic Material Model(DMM),processing maps for both regions under varying strain conditions were constructed,demonstrating superior workability in non-segregated regions.By integrating processing maps with microstructural observations,the optimal hot processing parameters were identified as 1050-1100℃/0.001-0.01 s^(-1).The segregated regions exhibited lower average grain misorientation angles and higher local strain,prone to dynamic recrystallization(DRX)at low temperatures and high strain rates.However,DRX grains coarsened significantly with increasing temperature and decreasing strain rate.These findings provide critical theoretical guidance for optimizing the hot processing of largescale GH4706 alloy,significantly enhancing the performance and service reliability of large GH4706 alloy components.

关 键 词：GH4706合金 凝固偏析 本构方程 热加工图 动态再结晶 

分 类 号：TG142.1[一般工业技术—材料科学与工程]