The influence of chemical composition and annealing parameters on the behavior of FeTiP precipitation has been investigated. With increasing Ti content the yield strength and tensile strength were reduced, and the ten...The influence of chemical composition and annealing parameters on the behavior of FeTiP precipitation has been investigated. With increasing Ti content the yield strength and tensile strength were reduced, and the tendency of FeTiP precipitation became more remarkable. No FeTiP precipitate was observed and the best mechanical properties have been obtained in the steel sheet, of which the atom ratio of Ti to N is approximately equal to 1. In the temperature range of 700 to 800℃ the FeTiP precipitation could appear easily. The precipitation process was suppressed when the annealing temperature was below 600℃, and the FeTiP phase was dissolved above 900℃. The FeTiP precipitates would inhibit the migration of grain boundaries during the recrystallization in certain extent, and weaken the density of {111} fiber texture, which resulted in the reduction of r value. The relationship between composition and processing parameters, as well as their influence on the mechanical properties is discussed.展开更多
The precipitation behavior of FeTiP in interstitial free high strength（IFHS）steels has been studied by using a transmission electron microscope（TEM）.The results show that the TiC particles,appearing at earlier sta...The precipitation behavior of FeTiP in interstitial free high strength（IFHS）steels has been studied by using a transmission electron microscope（TEM）.The results show that the TiC particles,appearing at earlier stage,are more stable than the FeTiP ones during recrystallization annealing at the two given temperatures（810℃ and 840℃）.Therefore,the FeTiP particles can only be observed in the steels with sufficient amount of Ti.There is a critical forming time for the FeTiP,which is between 90-120 sat 810 ℃ and 60-90 sat 840 ℃.The precipitation of FeTiP involves two steps,i.e.the formation of FeTi precursors and the diffusion of P.The former step determines the reliance of Ti content for the precipitation of FeTiP,whereas the latter step leads to the difference in the critical annealing time.展开更多
文摘The influence of chemical composition and annealing parameters on the behavior of FeTiP precipitation has been investigated. With increasing Ti content the yield strength and tensile strength were reduced, and the tendency of FeTiP precipitation became more remarkable. No FeTiP precipitate was observed and the best mechanical properties have been obtained in the steel sheet, of which the atom ratio of Ti to N is approximately equal to 1. In the temperature range of 700 to 800℃ the FeTiP precipitation could appear easily. The precipitation process was suppressed when the annealing temperature was below 600℃, and the FeTiP phase was dissolved above 900℃. The FeTiP precipitates would inhibit the migration of grain boundaries during the recrystallization in certain extent, and weaken the density of {111} fiber texture, which resulted in the reduction of r value. The relationship between composition and processing parameters, as well as their influence on the mechanical properties is discussed.
基金Item Sponsored by National Natural Science Foundation of China(50901054,51101114)
文摘The precipitation behavior of FeTiP in interstitial free high strength（IFHS）steels has been studied by using a transmission electron microscope（TEM）.The results show that the TiC particles,appearing at earlier stage,are more stable than the FeTiP ones during recrystallization annealing at the two given temperatures（810℃ and 840℃）.Therefore,the FeTiP particles can only be observed in the steels with sufficient amount of Ti.There is a critical forming time for the FeTiP,which is between 90-120 sat 810 ℃ and 60-90 sat 840 ℃.The precipitation of FeTiP involves two steps,i.e.the formation of FeTi precursors and the diffusion of P.The former step determines the reliance of Ti content for the precipitation of FeTiP,whereas the latter step leads to the difference in the critical annealing time.
