Abstract: Test 0. 8 mm cold rolled sheet of 390 MPa IF steel (/%: 0. 005C, 0.04Si, 0. 35Mn, 0. 095P, 0. 005S, 0. 030Nb, 0. 016Ti, 0. 036Alt) is cold rolled by 4 mm hot rolled plate. The effect of continuous annealing temperature 780 ~ 820 °C on structure, texture and mechanical properties of the IF steel has been studied. Results show that as continuous annealing temperature increases from 780 ℃ to 820 ℃, the yield and tensile strength of the IF steel decrease respectively from 282 MPa and 432 MPa to 249 MPa and 405 MPa, and the elongation A₅₀ and plastic strain ratio r_m increase respectively from 37. 2% and 1.45 to 41. 7% and 1. 84, it has better deep drawing property while with increasing annealing temperature the plane anisotropic index △r   increases from 0. 44 to 0. 65, grain size of ferrite increases， and structure homogeneity becomes poor, and deformation texture {112} < 110 > is weaker, favorable texture {111} < 110 > is enhanced, texture {001}<110> weakens, comprehensively considering, the suitable annealing temperature is about 820 ℃.

摘要： 试验用390 MPa级IF钢(/%:0.005C,0.04Si,0.35Mn,0.095P,0.005S,0.030Nb,0.016Ti,0.036Alt)0.8 mm冷轧板由4 mm热轧板冷轧生产。研究了连续退火温度780~820℃对该IF钢组织、织构和力学性能的影响。结果表明,当连续退火温度由780℃提高至820℃时,IF钢的屈服和抗拉强度分别由282 MPa和432 MPa降至249 MPa和405 MPa,伸长率A₅₀和塑性应变比r_m分别从37.2%和1.45提高到41.7%和1.84,具有较好的深冲性能;但随退火温度升高,平面各向异性指数△r由0.44提高到0.65,铁素体晶粒尺寸增大,组织均匀变差,同时变形织构{112}<110>变弱,有利织构{111}<110>增强,{001}<110>变弱,综合考虑退火温度控制在820℃左右为宜。

关键词: IF钢, 连续退火温度, 力学性能, 组织, 织构