B含量对含磷高强IF钢再结晶及织构的影响

Influence of B content on recrystallization and texture of P-containing high strength IF steel

采用氮气炉加热模拟薄板坯连铸连轧生产线罩式退火工艺,研究了不含B与含适量B的含磷高强IF钢210P1冷轧板再结晶规律;采用X射线衍射仪对不同B含量的罩式退火成品板进行了织构分析;对成品板的显微组织进行了观察并对现场生产的不同B含量钢板的r90值进行了统计。结果表明：将B含量控制在0.0005%～0.0007%时,冷轧钢板罩式退火再结晶温度与不含B的冷轧钢板基本相同,甚至再结晶更充分些,而且加适量的B可解决含磷IF钢二次加工脆性问题,成品板具有较高强度的有利织构{111}〈110〉和{111}〈112〉、较高的{111}/{100}比值以及较高的成形性能指标r90值,成品板的饼形晶粒更大。当B含量超过0.0009%时,再结晶晶粒较小且不均匀,有利织构较弱,塑性应变比r（90）值较低。

Recrystallization laws of high strength IF steel plate 210 P1 without B and with appropriate B addition were studied by using nitrogen heating furnace; texture analysis of batch annealing finished plates with different B content was carried out by adopting X-ray diffraction; microstructure of finished plates was observed and the r90 values of steel plates with different B content were calculated.The results show that if B content in 210P1 steel plate is controlled in the range of 0.0005%-0.0007%,the recrystallization annealing temperature of cold rolled steel plate is basically the same as that of the steel plate without B,the recrystallization process is completed more fully,the finished plate has both the resistance of the secondary working embrittlement and favorable texture { 111} 110 and { 111 } 112 with higher intensity,higher { 111}/{ 100} ratio,higher forming performance index r（90） value,and larger pancake grain size.But if the B content in steel plate exceeds 0.0009%,the recrystallization grains are smaller and less uniform,favorable texture are weak and the plastic strain ratio r（90） value is lower.