摘要
目的针对GH4169锭型逐渐增大、铸锭开坯时的锻透性更差的问题,通过有限元模拟技术,探究开坯阶段坯料温度、等效应变与晶粒组织的分布及演变特征,以优化开坯工艺设计。方法利用DEFORM-3D平台,基于弹塑性有限元法建立三维热力耦合模型,对GH4169镍基高温合金铸锭的开坯自由锻造工艺进行数值模拟。结果模拟结果表明,镦粗后坯料芯部温度可达1110℃,径向温差小于50℃,芯部与边缘等效应变差值约0.2,再结晶体积分数最高达36%;终锻时,坯料温度为970~1070℃,表面应变约7.5,芯部应变约4,晶粒尺寸均小于20μm,且径向尺寸差小于10μm,组织均匀性得到显著提升;损伤因子分析结果揭示了最大损伤区域的分布规律。结论所设计的工艺流程显著改善了GH4169合金的微观组织,使晶粒均匀细化,有效提升了锻件的组织均匀性,为优化GH4169合金大规格铸锭的开坯工艺提供了理论依据。
Aiming at the problem that the shape of GH4169 ingots increases gradually and the forging permeability becomes worse during cogging of ingots,the work aims to reveal the distribution and evolution of billet temperature,equivalent strain and grain structure during billet cogging through finite element simulation,so as to design the billet cogging process more scien-tifically.In this study,the DEFORM-3D platform was used to develop a three-dimensional thermomechanical coupling model based on the elastoplastic finite element method for simulating the cogging free forging process of GH4169 nickel-based super-alloy ingots.The simulation results showed that after upsetting,the core temperature reached 1110℃ with a radial temperature difference less than 50℃,while the equivalent strain difference between the core and the edge was about 0.2,and the maximum recrystallization volume fraction reached 36%.Upon final forging,the billet temperature ranged from 970 to 1070℃,surface strain was about 7.5 and core strain was about 4.The grain size was refined to less than 20μm with a radial size difference less than 10μm,indicating significantly improved microstructural homogeneity.Damage factor analysis revealed the distribution of maximum damage zones.In conclusion,the findings indicate that the designed process significantly refines the microstructure of the GH4169 alloy,achieving uniform grain refinement and markedly improving the overall microstructural homogeneity of the forged product.This provides a robust theoretical foundation for optimizing the cogging process for large-scale GH4169 al-loy ingots.
作者
吴雨萌
姚志浩
董建新
WU Yumeng;YAO Zhihao;DONG Jianxin(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)
出处
《精密成形工程》
北大核心
2025年第8期136-149,共14页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52271087,52471110)
国家科技重大专项项目(J2017-VI-0017-089)。
