摘要
某钢厂在生产Q355B带钢时存在冲击性能不合格的现象,为了研究热轧过程中对Q355B冲击性能的影响因素。本文结合现场生产状况,利用光学显微镜、冲击试验机等检测手段,分析了各阶段轧制工艺对组织和性能的影响。结果表明,Q355B带钢冲击不合格是由于粗轧末道次温度高和轧制压下率小,导致组织产生晶粒粗大、异常贝氏体组织和混晶现象,并且冬季外部环境温度低、冷速快,也易使带钢表面和偏析处形成贝氏体组织。通过采取降低粗轧末道次温度、增加精轧压下率、降低终轧温度等措施后,Q355B的带钢组织明显改善,冲击性能合格率达到98.5%。
A steel mill has the phenomenon of unqualified impact properties during the production of Q355B strip.In order to study the factors affecting the impact properties of Q355B during hot rolling.In this paper,combined with the on-site production conditions,the influence of the rolling process at each stage on the microstructure and properties is analyzed by means of optical microscopes,impact testing machines and other detection methods.The results show that the unqualified impact of Q355B strip steel is due to the high final pass temperature of rough rolling and low rolling reduction rate,resulting in coarse grains,abnormal bainite structure and mixed crystal phenomenon.The cooling rate is fast,and it is easy to form bainite structure on the surface and segregation of the strip.After formulating corresponding process optimization measures,the strip structure of Q355B is significantly improved,and the qualified rate of impact performance reaches 98.5%.
作者
周靓
赵忠云
粟劲超
周波
杨进
ZHOU Liang;ZHAO Zhongyun;SU Jinchao;ZHOU Bo;YANG Jin(Hot Rolled Plate and Strip Plant,Guangxi Liuzhou Iron and Steel Group Co.,Ltd.,Liuzhou 545000,Guangxi,China)
出处
《四川冶金》
CAS
2023年第1期61-65,共5页
Sichuan Metallurgy
关键词
Q355B
冲击性能
金相组织
轧制压下率
粗轧末道次温度
Q355B
impact properties
metallographic structure
rolling reduction rate
final pass temperature of rough rolling
