Research on Microstructure and Property Control of High Strength Nb Bearing Hot-Rolled DP Steel
In the light of transformation rule of C-Si-Mn-Cr-MoNb tested steel,thermal mechanical simulation of twopass deformation and step cooling on Gleeble-1500 thermal simulator and rolling experiment in laboratory were carried out to analyze the effect of process data such as deformation temperature and reduction,step-cooling process data,coiling temperature on microstructure and mechanical properties of high strength Nb bearing hot-rolled DP steel. It is obtained that,along with the increasing of holding time at 700℃ ,percentage of ferrite increases obviously and ferrite grain size coarsens appreciably. When holding time is up to 20s,volume of ferrite is close to 80%. When coiling temperature is 600t,microstructure of tested steel is ferrite and martensite with mechanical property of YS =450 MPa,TS =730 MPa,EL= 23. 6% and YS/TS=0. 62; When coiling temperature reduces to 500t ,dual phase microstructure of ferrite and bainite is obtained,and YS increases by 55 MPa,TS decreases by 50 MPa,EL increases appreciably and YS/TS increases to 0. 74,compared to that coiled at 600℃.
hot-rolled DP steel step cooling microstructure evolution
Zhou Leyu Liu Yazheng Jia Song Fang Yuan Song Renbo
School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China
国际会议
2009 International Symposium on Automobile Steel(2009年汽车用钢生产及应用技术国际研讨会)
大连
英文
242-247
2009-09-06（万方平台首次上网日期，不代表论文的发表时间）