Effect of Niobium Addition on Hot Deformation Behaviors of Medium Carbon Ultra-high Strength Steels  

作　　者：杨秀芝 张李超 史玉升 YU Shengfu HUA Wenlin 

机构地区：[1]Hubei Polytechnic University,Huangshi 435003,China [2]State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials,Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2017年第1期162-172,共11页武汉理工大学学报（材料科学英文版）

基　　金：Supported by the National 863 Program of China(No.2015AA042505);Hubei Department of Education Youth Program(No.Q20123001);Hubei Province Natural Science Foundation(No.2014 cfb177);Wuhan Huaxia Fine Blanking Technology Co.,LTD Program(No.YYYY2014-015)

摘　　要：The hot deformation behaviors of two medium carbon ultra-high strength steels with different niobium contents were investigated by using Zener-Hollmom parameter and processing map,and the effect of niobium addition on the hot deformation behavior of medium carbon steel was determined.The hot compression tests were conducted on a Gleeble-3500 thermo-mechanical simulator deformed at temperatures from 850 to 1 200 ℃ and strain rates from 0.001 to 1 s^-1.The processing maps of two test steels were built at a true strain of 0.7 based on dynamic materials model（DMM）.There are two peak efficiency domains and two flow instability regions in both test steels.However,the peak efficiency domains of Nb-bearing steel move to higher temperature due to the inhibition of dynamic recrystaUization（DRX）,and the instability domains of Nb-bearing steel are enlarged due to the precipitation of Nb-containing particles during hot deformation.The optimum process parameters of Nb-bearing and Nb-free steels for industrial production were determined according to the processing map and the microstructural observation.The hot deformation behaviors of two medium carbon ultra-high strength steels with different niobium contents were investigated by using Zener-Hollmom parameter and processing map,and the effect of niobium addition on the hot deformation behavior of medium carbon steel was determined.The hot compression tests were conducted on a Gleeble-3500 thermo-mechanical simulator deformed at temperatures from 850 to 1 200 ℃ and strain rates from 0.001 to 1 s^-1.The processing maps of two test steels were built at a true strain of 0.7 based on dynamic materials model（DMM）.There are two peak efficiency domains and two flow instability regions in both test steels.However,the peak efficiency domains of Nb-bearing steel move to higher temperature due to the inhibition of dynamic recrystaUization（DRX）,and the instability domains of Nb-bearing steel are enlarged due to the precipitation of Nb-containing particles during hot deformation.The optimum process parameters of Nb-bearing and Nb-free steels for industrial production were determined according to the processing map and the microstructural observation.

关 键 词：Nb addition hot workability processing map rolling process 

分 类 号：TG142.1[一般工业技术—材料科学与工程]