Q345B钢板卷制开裂原因分析  

Causes Analysis on Roll Bending Cracks of Q345B Steel Plate

作　　者：付振坡 付冬阳 刘丹 刘沼 袁平 师帅 赵晓辉 Fu Zhenpo;Fu Dongyang;Liu Dan;Liu Zhao;Yuan Ping;Shi Shuai;Zhao Xiaohui(HBIS Group Wusteel Company)

机构地区：[1]河钢集团舞钢公司

出　　处：《宽厚板》2020年第6期13-15,共3页Wide and Heavy Plate

摘　　要：某钢厂生产40 mm厚度Q345B钢板在卷制过程中开裂,导致无法使用。为了探究开裂的原因,防止其再次发生,利用低倍组织热酸浸检验装置、金相显微镜对卷制开裂钢板进行检测分析。结果表明:钢板中存在大量硫化物、严重的局部C、S偏析以及偏析带马氏体硬相组织、较高的氢含量,三者共同作用导致钢板出现原始裂纹,并在卷曲过程中扩展至表面,致使钢板开裂。通过实施冶炼工艺改进措施,将钢液中的硫化物夹杂由原来的2.0级降低至0.5级,同时消除了局部偏析,最终解决了钢板的卷制开裂问题。Cracking occurs on 40 mm thick Q345 B steel plate produced by a steel works during roll bending,resulting in rejection.In order to find out the causes of steel plate roll bending cracks and prevent their reoccurance,test and analysis on the steel plate are performed by means of macrostructure hot acid etching device and metallographic microscope.The results show that there exist a large number of sulfide,severe local C and S segregation and martensite hard phase structure at segregation band,higher hydrogen content,which jointly leads to original cracking in steel plate.The original cracks in steel plate propagate to the plate surface during roll bending and lead to plate cracking.By implementing improvement measures of melting process,the rating of sulfide inclusions in steel is reduced from previous 2.0 to current 0.5,local segregation is eliminated as well,thus the cracking problem during plate roll bending is resolved.

关 键 词：Q345B钢板 卷制开裂 工艺改进 

分 类 号：TG335[金属学及工艺—金属压力加工]