摘要
目的研究紧固件用冷拔态GH4738合金棒材在不同工艺参数下的热变形行为,为紧固件热加工工艺参数优化提供理论指导。方法采用Gleeble-3500热模拟实验机对冷拔态GH4738合金棒材在变形温度1000~1080℃、应变速率1~10 s^(−1)条件下进行了热压缩实验,变形量为50%。计算了该合金的材料常数和变形激活能Q,建立了基于峰值应力的冷拔态GH4738合金的本构方程,根据动态材料模型理论绘制了冷拔态GH4738合金的能量耗散图和失稳图,获得了合金在不同应变下的热加工图,并讨论了显微组织演变情况。结果冷拔态GH4738合金的流变应力随着变形温度的增加或应变速率的减小而降低。线性回归的相关系数证实了描述该材料热变形行为的本构方程的准确性。基于冷拔态GH4738合金的热加工图及显微组织验证结果可得,冷拔态GH4738合金的主要失稳区工艺参数区间为1000~1035℃/0.12~3s^(−1),1030~1072℃/0.25~10 s^(−1)和1075~1080℃/2.72~10 s^(−1)。热加工较佳工艺条件为1000~1028℃/0.02~0.14 s^(−1)和1040~1080℃/0.06~0.74 s^(−1)。结论通过对冷拔态GH4738合金热变形本构方程和热加工图进行研究,获得了冷拔态GH4738合金优化的热变形工艺参数,可用于指导冷拔态GH4738合金的紧固件热加工成形。
The work aims to study the hot deformation behavior of cold-drawn GH4738 alloy bars for fastener under different process parameters,providing theoretical guidance for optimizing the hot processing parameters of fasteners.Hot compres-sion tests were performed by a Gleeble-3500 machine at deformation temperature of 1000-1080℃and strain rate of 1-10 s^(−1),with a deformation of 50%.The material constants and deformation activation energy Q of the alloy were calculated,and a con-stitutive equation based on peak stress for cold-drawn GH4738 alloy was established.Energy dissipation maps and instability maps of the cold-drawn GH4738 alloy were drawn based on the theory of dynamic material models.Hot processing maps of the alloy under different strains were obtained,and the evolution of the microstructure was discussed.The results showed that the flow stress of the cold-drawn GH4738 alloy decreased with increasing deformation temperature or decreasing strain rate.The accuracy of the constitutive equation describing the hot deformation behavior of the material was confirmed by the correlation coefficient of linear regression.Based on the hot processing maps and microstructure verification results of the cold-drawn GH4738 alloy,the main instability zone ranges were 1000-1035℃/0.12~3 s^(−1),1030-1072℃/0.25~10 s^(−1),and 1075-1080℃/2.72-10 s^(−1).The optimal process conditions for hot processing were 1000-1028℃/0.02-0.14 s^(−1)and 1040-1080℃/0.06-0.74 s^(−1).Through the study of the constitutive equation and hot processing maps of the cold-drawn GH4738 alloy,the optimal hot deformation process parameters have been obtained,which can be used to guide the hot forming processes of fasteners made from cold-drawn GH4738 alloy.
作者
田曾
金万军
王倩
张欢欢
吴大勇
马海坤
董会苁
苏孺
TIAN Zeng;JIN Wanjun;WANG Qian;ZHANG Huanhuan;WU Dayong;MA Haikun;DONG Huicong;SU Ru(Hebei Key Laboratory of Material Near-net Forming Technology,School of Material Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050018,China;China Aviation Industry standard Parts Manufacturing Co.,Ltd.,Guiyang 550000,China;AVIC Shangda Superalloy Materials Co.,Ltd.,Hebei Xingtai 054800,China)
出处
《精密成形工程》
北大核心
2024年第5期193-200,共8页
Journal of Netshape Forming Engineering
基金
河北省重点研发计划(22351008D)
河北省科技创新项目(SJMYF2022X04)
中国航发自主创新专项资金(CXPT-2021-010)。
关键词
GH4738合金
热变形
本构方程
热加工图
微观组织
GH4738 alloy
hot deformation
constitutive equation
hot processing map
microstructure
