Q345B钢板冷弯开裂原因分析及改进措施  

Cause Analysis and Improvement Measures of Cold Bending Cracking of Q345B Steel Plate

作　　者：李惠娟[1] LI Hui-juan(Tianjin Iron and Steel Group Co.,Ltd.Tianjin 300301,China)

机构地区：[1]天津钢铁集团有限公司产品质量部,天津300301

出　　处：《天津冶金》2018年第A01期42-45,共4页Tianjin Metallurgy

摘　　要：通过采用宏观检验、化学成分分析、力学性能检测以及金相检测等方法对Q345B钢板冷弯开裂样品进行分析。结果表明,冷弯开裂的主要原因是硫化物夹杂过多。硫化物夹杂在冷弯过程中易碎裂或与基体组织分离产生孔隙并成为裂纹源,且硫化物夹杂易导致轧钢过程中出现带状组织,而严重的带状组织也加剧了宏观裂纹的形成。提出了采用铁水预处理脱硫、增加吹氩强度、保证吹氩时间、增大轧制冷却速度等方法改善Q345B钢板的塑性和韧性,降低冷弯开裂的几率的建议。The cold bending cracking samples of Q345B steel plate were analyzed by macroscopical examination, chemical composition analysis, mechanical property test and metallographic examination. The results show that the main reason of cold bending cracking is too many sulphide inclusions are prone to break or separate from the matrix to form pores and become the source of cracks during cold bending, and the inclusion of sulfides can lead to the appearance of banded structures during rolling, and the formation of macroscopic cracks is aggravated by the serious banded structure. Some suggestions are put forward to improve the ductility and toughness of Q345B steel plate and reduce the probability of cold bending cracking by means of desulphurizing pretreatment of molten iron, increasing argon blowing strength, ensuring argon blowing time and increasing rolling cooling rate.

关 键 词：冷弯裂纹 硫化物夹杂 带状组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG335[金属学及工艺—金属材料]