【摘要】 研究了退火工艺对含Nb高强冷轧无取向硅钢组织、磁性能与力学性能的影响。退火温度升高与退火时间延长均可导致Nb在晶界处的偏聚减弱、富Nb析出相粒子的固溶与粗化,因此阻止晶界迁移的钉扎力降低,晶粒长大;富Nb相粒子粗化与晶粒长大均可降低铁损,但也同时使得强度显著降低。因此,含Nb高强冷轧无取向硅钢的磁性能与力学性能无法同时得到优化。当采用940℃保温270 s退火工艺后,Nb偏聚于该钢晶界并同时有大量富Nb相粒子析出,有效抑制了晶粒长大与g织构的发展,可以在磁感和铁损尚未明显恶化的情况下,通过晶粒细化和析出强化有效提高该钢的屈服强度,达到该钢磁性能与力学性能的最佳匹配,此时磁感应强度B₅₀为1.690 T,铁损P_1.5/50为4.86 W/kg,P_1.0/400为30.47 W/kg,屈服强度为505 MPa,断后伸长率为17.55%。更多还原

【Abstract】 As the core material of transaction motor for electrical/hybrid vehicles, the non-oriented silicon steel（NOSS） sheets require not only the good magnetic properties, i.e. high permeability and low iron loss, but also high yield strength to resist the centrifugal force during the high speed rotation. In this work, Nb element was added into the conventional NOSS to improve the strength without sacrificing the good magnetic properties too much. The effects of annealing process on the microstructures, magnetic and mechanical properties of Nb-containing high-strength non-oriented cold-rolled silicon steel were studied. The increases of annealing temperature and time both lead to the reduced segreation of Nb at grain boundaries and the solution and ripening of precipitates, which means the decreased suppression on the migration of grain boundaries; thus, the recrystallized grains start to grow; particularly, the density of{111} <112> texture component may increase to deteriorate the magnetic flux density, B50. The best mechanical and magnetic properties cannot be achieved at the same time. The annealing process at 940 ℃for 270 s could lead to the best combination of mechanical and magnetic properties, which include B₅₀ of 1.69 T, the iron loss P_1.5/50 of 4.86 W/kg and P_1.0/400 of 30.47 W/kg, resulting from both the segregation of solute Nb at grain boundaries and the extensive precipitation which refrains the grain growth and development of harmful g texture. Therefore, the yield strength is increased due to both grain refinement and precipitation strengthening without greatly sacrificing the permeability and iron loss.更多还原