Nano-precipitates and its strengthening effect in high grade pipeline steels
Through the organic integration of microalloying,controlled rolling and cooling technology,large quantities of nano-precipitation particles were obtained in high grade pipeline steels.The morphology of these particles were observed and analyzed.Quantitative analysis was presented on the size distribution and the precipitation strengthening effect of nano-precipitation particles.Precipitation regularity of the Nb ( C,N) in Austenite was analyzed through dynamic calculation.The results showed that: there were mainly two types of precipitation phase in high grade pipeline steel,the smaller size of NbC precipitate ( 1 ~ 30 nm) and ( Ti,Nb) ( C,N) composite precipitate (50 ~ 300 nm),both of which were face-centered cubic structure;the contribution value of carbonitride second phase precipitation of X80/X100 steels on strength was about 50MPa;the dynamic calculations of Nb ( C,N) precipitated phase in high grade pipeline steels showed that when the high grade pipeline steels were produced on hot strip mill line the content of microalloy carbonitride precipitation was less than 10% in hot rolling process and the rest 90% were precipitated in the subsequent cooling process;in plate mill and Steckel mill production process of high grade pipeline steels,the precipitation of microalloy carbonitride was nearly 70% in hot rolling stage,the remaining 30% mainly precipitated in the subsequent cooling process.
high grade pipeline steels nano-particles precipitation strengthening
ZHANG Hesong KANG Yonglin
School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100 School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100
国内会议
上海
英文
1-7
2013-06-01（万方平台首次上网日期，不代表论文的发表时间）