Abstract: The surface scabs of 1028 cold heading steel wire rod are analyzed by metallurgy and scanning electron microscope. It is concluded that the main reason is the high nitrogen content (0. 0133% ) in the steel, the Ti in steel (0.033% ) is not enough to completely fix nitrogen, and the excess N with B formes BN precipitates to weaken the grain boundary and form microcracks led to the surface cracking of the billet and finally inherited to wire rod surface after rolling. By reducing the scrap ratio from 21% to 10% and the deoxidization intensity of tapping, adding ferroboron after feeding Ti- Fe wire for 5 min after white slag, controlling the soft blowing volume of LF, and aluminum loss ≤0.003% during casting process, N is stably controlled within 60 x 10 ^-6 to ensure Ti/≥4, the defective rate of surface scabbing is reduced from original 60% to less than 1. 0% .

Key words: 10B28 Steel, Cold Heading Steel Wire Rod, Surface Scab, Causes Analysis, Process Improvement ,

摘要： 采用金相显微镜和扫描电镜分析了10B28冷镦钢线材表面结疤,得出结疤缺陷形成的主要原因是钢中N含量偏高（0.013 3%）,钢中的Ti（0.033%）不足以完全固N,过剩N与B形成BN析出物,弱化晶界,形成微裂纹,导致铸坯表面开裂,最终经轧制后遗传到线材表面。通过将废钢比由21%降低为10%、降低出钢脱氧强度、造完白渣喂入钛铁线5 min后加入硼铁、控制LF软吹底吹气量和浇注过程铝损≤0.003%等措施,将N稳定控制在60×10^-6以下,保证Ti/N≥4,使表面结疤不良率由原来的60%降低至1.0%以下。

关键词: 10B28钢, 冷镦钢线材, 表面结疤, 成因分析, 改进工艺