弹簧钢60Si2Mn铸坯表面凹陷缺陷分析与工艺优化  

ANALYSIS AND PROCESS OPTIMIIZATION OF SURFACE DEPRESSION DEFECTS ON SPRING STEEL 60Si2Mn CASTINGS

作　　者：李春艳 刘海啸[1] 张冬冬 吕金峄 Li Chunyan;Liu Haixiao;Zhang Dongdong;LüJinyi(University of Seience and Technology Liaoning;Henan Jiyuan Iron and Steel(Group)Co,Ltd.)

机构地区：[1]辽宁科技大学,辽宁鞍山114051 [2]河南济源钢铁(集团)有限公司

出　　处：《河南冶金》2024年第6期25-28,50,共5页Henan Metallurgy

摘　　要：某炼钢厂在生产150 mm×150 mm弹簧钢60Si2Mn,磁粉探伤过程中观察到钢坯表面普遍分布着显著的渣沟缺陷,部分渣沟下存在裂纹,严重影响成品钢材质量。为解决这一问题,对结晶器振动参数、结晶器保护渣、结晶器铜管、整体浸入水口的状况进行排查。结果表明:振动参数和结晶器保护渣是造成该问题的主要因素。通过将振动频率由171 cpm降低至161 cpm,渣沟缺陷率由12.7%降低至7.5%;通过试验将结晶器保护渣的碱度优化到0.68,熔点优化到1 070℃,黏度优化到0.36 Pa.S,渣沟缺陷率由7.5%降低至3.8%;同时结晶器铜管保持镀层完整光滑,浸入式水口保持对中且浸入深度保持在95~115 mm,以保证结晶器内流场的均匀性和良好的润滑效果,确保结晶器弯月面处初生坯壳的均匀性,有效地减少了连铸坯表面渣沟缺陷的发生,连铸坯表面渣沟缺陷率降到1%左右。During the magnetic particle inspection of the 150 mm×150 mm spring steel 60Si2Mn produced by a certain steel plant,significant slag ditch defects were observed on the surface of the steel billet,and some cracks were found under part of the slag ditch,which seriously affected the quality of the finished steel.To solve this problem,the vibration parameters of the crystallizer,the protective slag of the crystallizer,the copper tube of the crystallizer and the condition of the submerged entry nozle were investigated.The results indicate that vibration parameters and crystallizer protective slag are the main factors causing this problem.By reducing the vibration frequency from 171 cpm to 161 cpm,the defect rate of slag ditch decreased from 12.7%to 7.5%;Through experiments,the alkalinity of the crystallizer protective slag was optimized to 0.68,the meling point was optimized to 1070℃,and theviscosity wasoptimized to 0.36Pa.S,thedefect rateoftheslag ditch was reduced from 7.5%to 3.8%;At the same time,the copper tube of the crystallizer maintains a complete and smooth coating,and the submerged entry nozzle is kept aligned and immersion depth is maintained at 195~115 mm to ensure the uniformity of the flow field and good lubrication effect inside the crystallizer,and to ensure the uniformity of the initial shell at the meniscus of the crystallizer.This effectively reduces the occurrence of slag ditch defects on the surface of the continuous casting billet,the defect rate is reduced to about 1%.

关 键 词：弹簧钢 渣沟缺陷 振动参数 保护渣 结晶器铜管 

分 类 号：TF777[冶金工程—钢铁冶金]