镧对高强IF钢连续退火过程中再结晶行为的影响

Effect of Lanthanum on recrystallization behavior of high strength IF steel during continuous annealing

在实验室进行冷轧高强IF钢薄板的再结晶退火试验,模拟连续退火工艺,对在820℃退火温度下保温不同时间(5~125 s)的试样,用金相显微镜和维氏硬度计测试试样的显微组织和显微硬度,研究稀土La元素对高强IF钢连续退火过程中再结晶行为的影响。结果表明,在连续退火过程中,稀土元素镧强烈推迟高强IF钢的再结晶开始时间,降低再结晶反应速率,抑制IF钢的再结晶行为。

Recrystallization annealing of cold-rolled plate of high strength interstitial-free steel was completed in laboratory,and continuous annealing tests were simulated by means of salt bath annealing method. Microstructure and microhardness of the tested steel treated at 820 ℃by different annealing time（ 5-125 s） was measured by metallurgical microscope and Vickers hardness tester,the effect of rare earth elements on recrystallization behavior during continuous annealing process of high strength interstitial-free steel was studied. The results show that adding the Lanthanum of rare earth element delays the process of annealing recrystallization of high-strength interstitial-free steel,and reduces the rate of recrystallization reaction.