Abstract: The effect of 4 group P-B content (/% : 0.076-0.110P, 0-0.0052B) on recrystallization textures, strength, elongation, work hardening exponent (n) and plastic strain ratio (r) of Ti-IF steel (/% : 0.001-0.003C, 0.06 -0.08Si, 0.32-0.38Mn, 0.002-0.008S, 0.036-0.076Ti, 0.0020-0.0040N) 0.75 mm cold rolled sheet after annealing at 810 ℃ for 120 s air cooling has been studied by using electron backscatter diffraction (EBSD) technique etc. Results show that all annealed Ti-IF steels with 4 group P-B content have fully recrystallized to get polygonal ferrite with main texture components {111} <112> and {111} <110>. As higher P content (0.110% ) and lower B content (0.0006% ) the strength of steel is higher (tensile strength 387.5 MPa, Yield strength 260 MPa) but the r value is lower (1.5)； as with suitable P and B content (0.089% P and 0.0052% B) , the strength and r value are all higher (tensile strength 367.3 MPa, yield strength 201.5 MPa and r value 1.95).

Key words: High Strength Ti-IF Steel, Phosphorus, Boron, Recrystallization Texture, Mechanical Properties

摘要： 利用电子背散射技术(EBSD)等研究了4种P-B成分(/%:0.076～0.110P和0～0.005 2B)对Ti-IF钢(/%:0.001～0.003C、0.06～0.08Si、0.32～0.38Mn、0.002～0.008S、0.036～0.076Ti、0.002 0～0.004 0N)0.75mm冷轧板810℃ 120 s空冷退火后再结晶织构、强度、伸长率、加工硬化指数(n)和塑性应变比(r)的影响。结果表明,4种P-B成分冷轧Ti-IF钢退火后均发生了完全再结晶,获得多边形铁素体晶粒,主要织构组分是{111}<112>和{111}<110>。当P含量较高(0.110%)、B含量较低(0.000 6%)时钢的强度较高(抗拉强度387.5MPa,屈服强度260 MPa),但r值较低(1.5);P、B含量适量(0.089%P、0.005 2%B),强度和r值均较高(抗拉强度367.3 MPa,屈服强度201.5 MPa,r值1.95)。

关键词: 高强度Ti-IF钢, 磷, 硼, 再结晶织构, 力学性能