Residual-stress relaxation mechanism and model description of 5052H32 Al alloy spun ellipsoidal heads during annealing treatment  

作　　者：Yong-Cheng Lin Jiang-Shan Zhu Jia-Yang Chen Jun-Quan Wang 

机构地区：[1]School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,People’s Republic of China

出　　处：《Advances in Manufacturing》2022年第1期87-100,共14页先进制造进展（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51775564);the Science and Technology Talent Promotion Project of Hunan Province(Grant No.2020TJ-Q05);the Fundamental Research Funds for the Central Universities of Central South University(Grant No.2020zzts495).

摘　　要：Marginal-restraint mandrel-free spinning is an advanced technology for manufacturing ellipsoidal heads with large diameter-thickness ratios.Nevertheless,the spinning-induced residual stress,which greatly influences the in-service performance of spun heads,should be removed.In this study,the effects of annealing on the residual-stress relaxation behavior of 5052H32 aluminum alloy spun heads were investigated.It is found that the residual stress first rapidly decreases and then remains steady with the increase in annealing time at the tested annealing temperatures.The relaxation of the residual stress becomes increasingly obvious with the increase in annealing temperature.When the annealing temperature is less than 220℃,there are no obvious changes in grain size.Moreover,the spinning-induced dislocations are consumed by the static recovery behavior,which decreases the residual stress during annealing.When the annealing temperature is approximately 300℃,the broken grains transform into equiaxed grains.In addition,static recrystallization and recovery behaviors occur simultaneously to promote the relaxation of the residual stress.Considering the different stress relaxation mechanisms,a model based on the Zener-Wert-Avrami equation was established to predict the residual-stress relaxation behavior.Finally,the optimized annealing temperature and time were approximately 300C and 30 min,respectively.

关 键 词：SPINNING Residual stress Annealing treatment Microstructure evolution Relaxation mechanism 

分 类 号：TG1[金属学及工艺—金属学]