Effect of Continuous Annealing on Microstructure and Bake Hardening Behavior of Low Carbon Steel  

作　　者：Chun-fu KUANG Jian WANG Jun LI Shen-gen ZHANG Hua-fei LIU Hong-lin YANG 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing [2]Research Institute,Baoshan Iron & Steel Co.,Ltd.

出　　处：《Journal of Iron and Steel Research International》2015年第2期163-170,共8页

基　　金：Sponsored by National Natural Science Foundation of China(51174247)

摘　　要：The influences of the heating rate, annealing temperature and soaking time during continuous annealing on the microstructure evolution and bake hardening behavior of the low carbon steel were investigated. After 2% pres- training, bake treatment （180 ℃ × 20 min） was carried out to measure BH （bake hardening） values. The results showed that, with the increase of the annealing temperature, the grain size increased except for annealing in the in- tercritical region. Furthermore, the BH value increased and the mean grain size reduced with increasing the heating rate from 5 to 80 ℃/s. The BH value was very low before complete recrystallization. After a significant decrease from 630 to 720 ℃ , the BH value enhanced when the steel was annealed at 750 ℃. With the increase of the soaking time from 20 to 100 s, the BH value reduced linearly due to the segregation of solute C atoms.The influences of the heating rate, annealing temperature and soaking time during continuous annealing on the microstructure evolution and bake hardening behavior of the low carbon steel were investigated. After 2% pres- training, bake treatment （180 ℃ × 20 min） was carried out to measure BH （bake hardening） values. The results showed that, with the increase of the annealing temperature, the grain size increased except for annealing in the in- tercritical region. Furthermore, the BH value increased and the mean grain size reduced with increasing the heating rate from 5 to 80 ℃/s. The BH value was very low before complete recrystallization. After a significant decrease from 630 to 720 ℃ , the BH value enhanced when the steel was annealed at 750 ℃. With the increase of the soaking time from 20 to 100 s, the BH value reduced linearly due to the segregation of solute C atoms.

关 键 词：continuous annealing low carbon steel bake hardening MICROSTRUCTURE BH value 

分 类 号：TG161[金属学及工艺—热处理] TG142.31[金属学及工艺—金属学]