To develop a methodology for evaluating fire resistance of high strength Q460 steel columns, the load bearing capacity of high strength Q460 steel columns is investigated. The current approach of evaluating load beari...To develop a methodology for evaluating fire resistance of high strength Q460 steel columns, the load bearing capacity of high strength Q460 steel columns is investigated. The current approach of evaluating load bearing capacity of mild steel columns at room temperature is extended to high strength Q460 steel columns with due consideration to high temperature properties of high strength Q460 steel. The critical temperature of high strength Q460 steel column is presented and compared with mild steel columns. The proposed approach was validated by comparing the predicted load capacity with that evaluated through finite element analysis and test results. In addition, parametric studies were carried out by employing the proposed approach to study the effect of residual stress and geometrical imperfections. Results from parametric studies show that, only for a long column （slenderness higher than 75）, the magnitude and distribution mode of residual stress have little influence on ultimate load bearing capacity of high strength Q460 steel columns, but the geometrical imperfections have significant influence on any columns. At a certain slenderness ratio, the stability factor first decreases and then increases with temperature rise.展开更多
The effects of TMCP parameters, consisting of finish cooling temperature and start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460 qNH steel were stud...The effects of TMCP parameters, consisting of finish cooling temperature and start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460 qNH steel were studied by tensile, Charpy impact tests and optical microscopy. The TMCP parameters for Q460 qNH steel were optimized by laboratory experiments. The results show that the yield strength and tensile strength increase with the finish cooling temperature, and the microstructure of Q460 qNH steel consists of ferrite and granular bainite.展开更多
基金The authors wish to acknowledge the support from the Funding Plan for Young Teachers in Universities of Chongqing, Natural Science Foundation of China （Grant No. 51008320）, China Postdoctoral Science Foundation （Grant No. 20110490811） and China Postdoctoral Science special Foundation （Grant No. 2012T50765）. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the sponsors.
文摘To develop a methodology for evaluating fire resistance of high strength Q460 steel columns, the load bearing capacity of high strength Q460 steel columns is investigated. The current approach of evaluating load bearing capacity of mild steel columns at room temperature is extended to high strength Q460 steel columns with due consideration to high temperature properties of high strength Q460 steel. The critical temperature of high strength Q460 steel column is presented and compared with mild steel columns. The proposed approach was validated by comparing the predicted load capacity with that evaluated through finite element analysis and test results. In addition, parametric studies were carried out by employing the proposed approach to study the effect of residual stress and geometrical imperfections. Results from parametric studies show that, only for a long column （slenderness higher than 75）, the magnitude and distribution mode of residual stress have little influence on ultimate load bearing capacity of high strength Q460 steel columns, but the geometrical imperfections have significant influence on any columns. At a certain slenderness ratio, the stability factor first decreases and then increases with temperature rise.
基金Funded by the Hi-Tech Research and Development Program of China(2003AA33G010)
文摘The effects of TMCP parameters, consisting of finish cooling temperature and start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460 qNH steel were studied by tensile, Charpy impact tests and optical microscopy. The TMCP parameters for Q460 qNH steel were optimized by laboratory experiments. The results show that the yield strength and tensile strength increase with the finish cooling temperature, and the microstructure of Q460 qNH steel consists of ferrite and granular bainite.
