摘要
GH4169高温合金在剪切-压缩变形后容易出现区域性微结构特征,这不利于后续的冷轧加工。在1000~1080℃温度范围内,保温1~3 h条件下进行再结晶退火处理以研究GH4169高温合金的微观组织演变行为,并通过调节晶粒大小优化其冷成形性能。结果表明,静态再结晶(SRX)在1000℃时完全形核,原有的粗大晶粒完全被细小的再结晶晶粒取代。大角度晶界(HAGB)的弓出位置是SRX的首选形核点。经1020~1060℃退火后,部分相邻的SRX晶粒之间发生吞并,导致一部分晶粒的尺寸增大,而初始动态再结晶(DRX)晶粒在应变集中区域仍保持微小的尺寸。再结晶晶粒(包括SRX和DRX)经1080℃退火后均匀长大,平均晶粒尺寸为87.89μm,此时显微组织的区域特征完全消失,组织均匀化程度明显提高。由于SRX的生长事故,经1080℃退火后出现了阶梯状孪晶,且孪晶界(Σ3)的长度分数达到35.8%,这有利于提高GH4169高温合金的高温持久性能。剪切-压缩变形态GH4169高温合金的最佳再结晶退火工艺最终被确定为1080℃保温1 h,水冷。
Regional microstructure characteristic always appears in shear-compression deformed GH4169 superalloy,which is detrimental to subsequent cold-rolling process in engineering.Recrystallization annealing treatments within temperature range of 1000-1080 ℃ and holding time range of 1-3 h were carried out to investigate the microstructure evolution behavior,and the cold-forming property of GH4169 superalloy was optimized by regulating the grain size.Results show that static recrystallization(SRX) grains are fully nucleated at 1000 ℃ and the original coarse grains are completely replaced by fine recrystallized grains.Bulges of high angle grain boundaries are the preferred nucleation points of SRX.At 1020-1060 ℃,grain annexation takes place among adjacent SRX grains,causing partial grains to increase,while the original dynamic recrystallization(DRX) grains keeps tiny in the strain concentration region.Recrystallized grains(both SRX and DRX) uniformly grow up,with an average grain size of 87.89 μm at 1080 ℃,at which the regional characteristic completely disappears,and the microstructure is significantly homogenized.Step twins appear at 1080 ° C due to the SRX growth accidents,and the length fraction of twin boundaries(Σ3) reaches 35.8%,which can effectively improve the high temperature resistance of GH4169 superalloy.Ultimately,the optimal recrystallization annealing of shearcompression deformed GH4169 superalloy is determined as 1080 ℃-1 h,followed by water cooling.
作者
陈乐利
高佩
罗锐
程晓农
孟宪凯
Chen Leli;Gao Pei;Luo Rui;Cheng Xiaonong;Meng Xiankai(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China;Technical Management Department,Jiangsu Yinhuan Precision Steel Tube Co.,Ltd,Yixing 214200,China;State Key Laboratory of Mechanical Transmission for Advanced Equipment,Chongqing University,Chongqing 400044,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2024年第7期1882-1886,共5页
Rare Metal Materials and Engineering
基金
State Key Laboratory of Mechanical Transmission for Advanced Equipment Project (SKLMT-MSKFKT-202219)
Natural Science Foundation of Jiangsu Province (BK20220548)
Open Research Fund from the State Key Lab of Advanced Metals and Materials,University of Science and Technology Beijing (2022-Z21)
National Natural Science Foundation of China (52005223)。
