退火温度对含磷高强IF钢FeTiP析出行为的影响

通过模拟罩式退火过程，研究了含磷高强IF钢中FeTiP粒子在退火过程中的析出行为，利用透射电镜选区衍射并结合能谱分析，确定了FeTiP的晶体结构.结果表明:650℃退火试样中只含有少量FeTiP，随着退火温度的升高，FeTiP数量明显增加，其大量分布于晶内及晶界处，且晶界处析出物尺寸明显大于晶内析出物.当退火温度升高到800℃时，FeTiP完全溶解，因此在整个基体无法检测到FeTiP.FeTiP的溶解消除了其对再结晶的阻碍作用，最终获得高强度{111}取向再结晶组织，从而提高高强IF钢成形的性能.FeTiP具有斜方晶体结构，且析出物中Nb元素的存在(含Nb原子可表达为Fe(Ti，Nb)P)不会引起晶体结构的改变.

Effect of Annealing Temperature on FeTiP Type Precipitate in P Added IF High Strength Steel

A systematic and detailed characterization of FeTiP type precipitate， as a function of annealing temperature， was studied for a batch annealed P added interstitial free high strength steel (IFHS). The results showed that a small number of FeTiP is observed at 650 ℃ and it increases dramatically with the increase of annealing temperature. FeTiP distributes within grains and at grain boundaries， but the size of intragranular FeTiP is found to be significantly smaller than that at grain boundary. FeTiP is totally dissolved and can not be detected at 800 ℃. The absence of FeTiP eliminates its inhibition effect on recrystallization and a high intensity {111} recrystallization texture is obtained， which improves the formability of IFHS. FeTiP is orthorhombic structure， and the enrichment of Nb in FeTiP precipitates does not alter the crystal structure of FeTiP.