Abstract: The structure,secondary phase precipitates and mechanical properties of 3 mm plates of 0.0045C-0.07Ti traditional Ti-IF steel contained 0.007P and 0.0052C-0.08Ti high strength Ti-IF steel contained 0.080P,which rolled by 4 pass in ferrite region between 800 ℃ and 680 ℃ from 24 mm plate slab, then annealed at 750℃ for 3 h,have been tested and studied. The results showed that the tensile strength of traditional Ti-IF steel was 270 MPa,the elongation 45% and the plastic strain ratio - r value 1.309,while the tensile strength of high strength Ti-IF steel was 315 MPa,the elongation 44% and the r value 1.098.The stucture of plates of both steels was recrystallized ferrite of which at center was coarser than that near surface,but there were secondary phase precipitates FeTiP in the high strength Ti-IF steel.

Key words: TI-IF Steel, Phosphorus, Rolling in Ferrite Region, Structure, Secondary Precipitate

摘要： 试验研究了含0.007%磷的普通Ti-IF(无间隙原子)钢(0.004 5%C-0.07%Ti)和含0.080%磷的高强度Ti-IF钢(0.005 2%C-0.08%Ti)24 mm板在800680℃铁素体区经4道次热轧成3 mm板,再经750℃3h退火后的组织、二相粒子和机械性能。试验结果表明,普通Ti-IF钢的拉伸强度为270 MPa,延伸率为45%,塑性应变比r值1.309,高强度Ti-IF钢的拉伸强度为315 MPa,延伸率44%,r值1.098。两钢板为再结晶铁素体组织,钢板中心组织较边部粗大,但在高强度Ti-IF钢中有FeTiP二相粒子析出。

关键词: Ti-IF钢, 磷, 铁素体区轧制, 组织, 二相粒子