Research And Development Of Q460E Micro Alloyed Steel

Based on problems of current production of plate steel， the tendency ofdeveloping new products, the process conditions and information of the production site,this paper introduced the simulation of temperature field of process in continuouscasting, roller conveying, heat preservation, stacks cooling and heating of Q460Emicro alloy steel. Further more, the changing of billet temperature was simulated andsystematic researched. The results showed the temperature fluctuation of billet couldbe effectively controlled by adjusting the casting speed, the secondary cooling system,the casting section and the superheat of liquid steel in casting process. The results alsoshowed that the greatest cooling rate of billets appear in the convey process; thetemperature of hot delivery has little impact on the cooling rate of billets in conveyprocess, and the cooling rate of the surface of billets was relatively greater than thecenter of billets.The impact of cooling rate and deformation on the formation of austenite ofQ460E steel was researched by dynamic continuous cooling transformation curve testof super-cooling austenite by using Gleeble3800thermal simulator in the test center.The results showed that super-cooling austenite transformation was significantlyinfluenced by deformation of non-recrystallization region in which ferrite nucleationrate was greatly increased, grain was refined and the volume percentage of ferrite wasincreased. Great deformation of Q460E steel in low temperature could lead to phasetransformation, promoting the nucleation of ferrite and prevent carbide from earlyformation. Smaller deformation of Q460E steel could lead to the formation of reticularferrite and coarse bainite microstructure. Greater rate of cooling could lead todecreasing in numbers of ferrite, smaller grain size, increasing in numbers of bainite and the layer of which was compact and fine. Lower final rolling temperature couldincrease the numbers of bainite.Micro-alloy Q460E steel was successfully developed in rational process ofsmelting, alloying, continuous casting and rolling after research of process conditionsand structure property as well as industrial experiment site adjustment of Q460E steelbillet and plate, which was improved the structure property and stability of Q460Esteel plate significantly.