B对Nb微合金化高强IF钢组织及二次加工脆性的影响  

Effect of B on microstructure and brittleness in secondary processing ofNb microalloyed high strength IF steel

作　　者：赵丁藏 刘景佳 付志平 ZHAO Dingzang;LIU Jingjia;FU Zhiping(Hunan Valin Lianyuan Iron and Steel Co.,Ltd.,Loudi 417009,China)

机构地区：[1]湖南华菱涟源钢铁有限公司,湖南娄底417009

出　　处：《轧钢》2023年第2期52-55,共4页Steel Rolling

摘　　要：为了提高Nb微合金化高强IF钢的抗二次加工脆性,研究了B对Nb微合金化高强IF钢组织及二次加工脆性的影响规律。研究结果表明:Nb微合金化高强IF钢中B的存在形式与Ti微合金化高强IF钢有所不同;当B添加量不足时,其只能以BN析出物的形式存在,对二次加工脆性没有改善效果;实验钢中的B被N固定后剩余的B以固溶形式存在(即有效B),只有在B含量遵循有效B质量分数大于0时,二次加工脆性转变温度随有效B含量的提高而降低,从而提高实验钢的抗二次加工脆性;当有效B质量分数大于0.000 7%时,实验钢的二次加工脆性转变温度不大于45℃并趋于稳定,其抗二次加工脆性达到最优。In order to improve the brittleness resistance in secondary processing of Nb microalloyed high strength IF steel,the effect of B on microstructure and brittleness in secondary processing of Nb microalloyed high strength IF steel was studied.The results show that the existing form of B in Nb microalloyed high strength IF steel is different from Ti microalloyed high strength IF steel.When the amount of B is insufficient,it can only exist in the form of BN precipitates,which has no effect on the brittleness in secondary processing of steel.After the B in the experimental steel is fixed by N,the remaining B exists in the form of solid solution(i.e.effective B).Only when the content of B follows the effective B mass fraction is greater than 0,the brittleness transition temperature in secondary processing decreases with the increase of the effective B content,so as to improve the brittleness resistance in secondary processing of the experimental steel.When the effective B mass fraction is greater than 0.0007%,the brittleness transition temperature in secondary processing of the experimental steel is less than 45℃and tends to be stable,its brittleness resistance in secondary processing reaches the optimum.

关 键 词：高强IF钢 NB微合金化 有效B 析出物 二次加工脆性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]