近β钛合金Ti-55511热塑性变形的流变应力分析与Arrhenius本构方程研究  

Flow stress analysis and Arrhenius constitutive equation of nearβtitanium alloy Ti-55511 during thermoplastic deformation

作　　者：罗登[1] 胡斌 王振 周文浩 孔玢 张晓泳[2] LUO Deng;HU Bin;WANG Zhen;ZHOU Wenhao;KONG Bin;ZHANG Xiaoyong(Xiangtan Iron&Steel Group Co.,Ltd.,Xiangtan 411100,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Hunan Xiangtou Goldsky Titanium Metal Co.,Ltd.,Changsha 410205,China)

机构地区：[1]湘潭钢铁集团有限公司,湘潭411100 [2]中南大学粉末冶金国家重点实验室,长沙410083 [3]湖南湘投金天钛金股份有限公司,长沙410205

出　　处：《粉末冶金材料科学与工程》2023年第3期212-222,共11页Materials Science and Engineering of Powder Metallurgy

基　　金：湖南省技术攻关“揭榜挂帅”项目(2021GK1080)。

摘　　要：主要研究Ti-55511钛合金在变形温度为700~850℃、应变速率为0.01~10 s-1、真应变为0.6条件下的热压缩变形行为。结果表明,Ti-55511钛合金的流变应力受变形温度和应变速率的影响显著,峰值应力随变形温度降低和应变速率升高而升高。为消除热压缩过程中的温升效应,提高模型的准确性,本文采用新的温度修正方法,即通过Arrhenius方程推导,并利用数学外推法,对实验流变应力曲线进行温度修正,修正结果表明,变形温度越低、应变速率越高,温升和流变应力增量越大。在温度修正的基础上,建立基于应变补偿的Arrhenius本构方程,用该本构方程预测的流变应力与实测流变应力之间的相关系数(R2)和平均绝对相对误差(average absolute relative error,AARE)分别为0.991和6.65%,表明用本构方程能够精确地预测不同热变形条件下的流变应力。Hot deformation behavior of Ti-55511 titanium alloy was studied at deformation temperatures of 700−850℃,strain rates of 0.01−10 s−1 and true strain of 0.6.The results indicate that the flow behavior of Ti-55511 titanium alloy is significantly affected by deformation temperature and strain rate.With the decrease of temperature and the increase of strain rate,the peak stress increases.In order to eliminate the deformation temperature rise effect in the process of hot compression and improve the accuracy of the model,a new temperature correction method was adopted in this paper.The temperature correction of the experimental flow stress curve was carried out through the Arrhenius constitutive equation derivation and combined with the mathematical extrapolation method.The results show that with the decrease of deformation temperature and the increase of strain rate,temperature rise and flow stress increment increase.The Arrhenius constitutive equation of strain-compensated is established,and the value of correlation coefficient(R2)and average absolute relative error(AARE)between experimental and predicted stress are 0.991 and 6.65%,respectively.This indicates that the established constitutive equation can accurately predict the flow stress under different thermal deformation conditions.

关 键 词：Ti-55511钛合金 热变形 流变应力 曲线修正 Arrhenius本构方程 

分 类 号：TG146.2[一般工业技术—材料科学与工程]