微合金化钢板断口分层开裂原因分析  

ANALYSIS OF THE CAUSES OF DELAMINATION CRACKING OF FRACTURES OF MICROALLOYED STEEL PLATES

作　　者：李洪波 高振伟 任志鑫 王金星 赵亚飞 孟凡超 Li Hongbo;Gao Zhenwei;Ren Zhixin;Wang Jinxing;Zhao Yafei;Meng Fanchao(Wu'an Yuhua Iron and Steel Co.,Ltd.,Handan 056300,Hebei;Jinan Iron and Steel Co.,Ltd.,Handan 056300,Hebei)

机构地区：[1]武安市裕华钢铁有限公司,河北邯郸056300 [2]冀南钢铁有限公司,河北邯郸056300

出　　处：《河北冶金》2023年第7期46-52,82,共8页Hebei Metallurgy

摘　　要：针对微合金化钢板断口分层的问题,以高强船板钢A36为研究对象,对炼钢-精炼-连铸-加热-轧制工艺进行了全面跟踪调查。使用金相显微镜、扫描电镜及能谱分析等设备研究了断口分层的原因。认为带状组织对船板钢的分层有较大影响,带状组织越严重,船板钢拉伸时分层越严重;夹杂物也是导致船板钢分层的原因之一,夹杂物仅为氧化物时断口正常,夹杂物为铝酸盐的复合夹杂物时,断口容易分层;带状组织的出现与化学成分偏析有关。通过降低Mn和S含量,提高合金含量,延长均热时间,控轧控冷等措施,船钢板的分层缺陷率由2020年的5.82%降低至2021年的0.56%,解决了船板钢分层缺陷问题。Aiming at the problem of fracture stratification of microalloyed steel plates,a comprehensive follow-up investigation of steelmaking-refining-continuous casting-heating-rolling process was carried out with high-strength ship steel A36 as the research object.The causes of fracture delamination were studied using metallographic microscopy,scanning electron microscopy,and spectroscopy.It is believed that the strip structure has a greater influence on the delamination of ship plate steel,and the more serious the band structure,the more serious the delamination when the ship plate steel is stretched.Inclusions are also one of the reasons for the delamination of ship plate steel,the fracture is normal when the inclusion is only oxide,and the fracture is easy to stratify when the inclusion is a composite inclusion of aluminate;the appearance of banded tissue is associated with chemical composition segregation.By reducing the Mn and S content,increasing the alloy content,extending the soaking time,controlling rolling and controlling cooling,etc.,the delamination defect rate of ship steel plate was reduced from 5.82%in 2020 to 0.56%in 2021,which solved the problem of delamination defect of ship steel plate.

关 键 词：船板钢 断口分层 中心疏松 元素偏析 带状组织 MNS 控轧控冷 

分 类 号：TG142.1[一般工业技术—材料科学与工程]