Effect of Cyclic Annealing on Microstructure and Mechanical Properties of Medium Carbon Steel  

作　　者：Zhi-qing LÜ Hui-fang ZHANG Qing MENG Zhen-hua WANG Wan-tang FU 

机构地区：[1]College of Mechanical Engineering,Yanshan University,Qinhuangdao 066004,Hebei,China [2]State Key Laboratory of Metastable Material Science and Technology,Yanshan University,Qinhuangdao 066004,Hebei,China

出　　处：《Journal of Iron and Steel Research International》2016年第2期145-150,共6页

基　　金：Item Sponsored by National Natural Science Foundation of China(51101137,51171161)

摘　　要：The microstructure and mechanical properties of medium carbon steel after cyclic heat treatment were in- vestigated. The effects of cyclic numbers and long time annealing on the microstructure and mechanical properties of the experimental steel were compared. A short duration （5 min） holding at 1023 K （above A1 temperature） and a short-duration （3 min） holding at 893 K are adopted in each cyclic heat treatment. The spheroidization is accelerated during cyclic heat treatment, and the spheroidizing ratio grows with cyclic numbers. After 12-cycle heat treatments, there are few incompletely spheroidized regions in the specimens, and cementite lamellae mostly change into cement- ite particles. The morphological character of cementite for 12 cycles is similar to that undergoing annealing for 10 h at 973 K. The strength of the experimental steel after 5-cycle heat treatment is the lowest in the following cyclic heat treatment, but it is still higher than that of specimens with subcritical annealing over a long period （10 h）. After 12- cycle heat treatment, the strength of the experimental steel is close to that of the normalized steel, and the plasticity is the best in all heat treated specimens.The microstructure and mechanical properties of medium carbon steel after cyclic heat treatment were in- vestigated. The effects of cyclic numbers and long time annealing on the microstructure and mechanical properties of the experimental steel were compared. A short duration （5 min） holding at 1023 K （above A1 temperature） and a short-duration （3 min） holding at 893 K are adopted in each cyclic heat treatment. The spheroidization is accelerated during cyclic heat treatment, and the spheroidizing ratio grows with cyclic numbers. After 12-cycle heat treatments, there are few incompletely spheroidized regions in the specimens, and cementite lamellae mostly change into cement- ite particles. The morphological character of cementite for 12 cycles is similar to that undergoing annealing for 10 h at 973 K. The strength of the experimental steel after 5-cycle heat treatment is the lowest in the following cyclic heat treatment, but it is still higher than that of specimens with subcritical annealing over a long period （10 h）. After 12- cycle heat treatment, the strength of the experimental steel is close to that of the normalized steel, and the plasticity is the best in all heat treated specimens.

关 键 词：rapid spheroidizing mechanical property cyclic annealing CEMENTITE medium carbon steel 

分 类 号：TF0[冶金工程—冶金物理化学]