航空用GH625镍基高温合金带材的成形极限研究  

Formability of GH625 Nickel-based Superalloy Strip for Aviation

作　　者：肖纳敏 雷宇 罗俊杰 孔祥任 王振[2] 贾崇林 沙爱学 XIAO Na-min;LEI Yu;LUO Jun-jie;KONG Xiang-ren;WANG Zhen;JIA Chong-lin;SHA Ai-xue(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095 [2]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《精密成形工程》2021年第1期51-60,共10页Journal of Netshape Forming Engineering

摘　　要：目的通过理论预测及胀形实验建立GH625高温合金的成形极限曲线,并结合仿真手段揭示其成形性能。方法首先,通过基本力学性能测试获取不同方向下GH625材料的基本力学参数;然后,基于颈缩理论和M-K理论模型预测GH625材料的成形极限曲线;其次,通过胀形实验建立相应的成形极限图,并与理论结果进行对比;最后,结合有限元方法进一步研究GH625材料的成形特性。结果准确获得了GH625高温合金的塑性应变比r值、应变硬化指数n值等参数;通过理论模型及胀形实验分别获得了相应的成形极限曲线,基于颈缩理论的集中性失稳预测结果与实验结果吻合较好;建立了可靠的有限元模型,进一步分析了摩擦因数及球头直径对GH625材料成形性能的影响规律。结论建立了准确的GH625材料成形极限曲线的理论预测模型,并通过半球胀形实验验证了理论结果的可靠性,数值仿真结果发现,较小的摩擦因数或者冲头直径有利于改善GH625材料在胀形实验中的失效位置。The work aims to obtain the forming limit curve(FLC) of GH625 superalloy via theoretical prediction and experiment, and further reveal its formability by numerical modeling. Firstly, the basic mechanical property of GH625 in various directions were obtained through basic mechanical property tests. Then, the forming limit curve of GH625 was predicted based on necking theory and M-K model. Next, the forming limit diagram was established through stamping test and were compared with the theoretical result. Finally, the formality of GH625 was comprehensively addressed using finite element method. In this study, the plastic strain ratio r and strain hardening parameter n of GH625 were accurately obtained. The corresponding FLCs were drawn by theoretical formulation and experiments. Predictive results based on necking theory together with centralized instability are proved to be in good agreement with the experimental results. Finally, the influence of the frictional coefficient and punch diameter on formality was analyzed by establishing reliable FEM model. The work develops an accurate model to theoretically predict the FLC of GH625 superalloy. Its reliability is validated by Nakazima formability tests. FEM simulation results show that the failure position can be improved by decreasing the frictional coefficient or punch diameter.

关 键 词：高温合金 成形极限曲线 理论预测 胀形试验 数值模拟 

分 类 号：TG389[金属学及工艺—金属压力加工]