Q355qD钢材中厚板冲击性能不合格原因分析与改进措施  

Cause analysis and improvement measures for unqualified impact performance of Q355qD medium-thick plate

作　　者：潘建设 金海兵 杨治争 宋欢 PAN Jianshe;JIN Haibing;YANG Zhizheng;SONG Huan(Steelmaking Plant of Baowu Group Echeng Iron and Steel Co.,Ltd.,Ezhou 436000,China;Baowu Central Research Institute Wuhan Branch,Wuhan 430080,China)

机构地区：[1]宝武集团鄂城钢铁有限公司炼钢厂,鄂州436000 [2]宝武中央研究院武汉分院,武汉430080

出　　处：《江西冶金》2025年第1期55-60,共6页Jiangxi Metallurgy

摘　　要：通过对Q355qD钢材中厚板冲击性能不合格试样进行冲击功分布、夹杂物特征和微观组织分析,确定了冲击性能不合格的主要原因是钢板内部出现严重的带状组织,同时冶炼纯净度和轧制稳定性对冲击性能也有一定的影响。本研究提出并实施了系列改进措施,具体包括限制转炉点吹次数,缩短钢包精炼炉(LF)精炼时间至8~12 min,提高底吹流量至500~600 L/min,控制连铸过热度低于25℃,提高轧制温度至1220~1230℃,终轧温度设定为810~850℃。工艺优化后,Q355qD钢材中厚板在-20℃的冲击韧性合格率由85.0%提高到99.2%,平均冲击功提高了50 J。By analyzing the impact energy distribution,inclusion characteristics and microstructure of Q355qD medium-thick plate samples with unqualified impact performance,it is determined that the main reason for the unqualified impact performance is the serious banded structure inside the steel plate.At the same time,the smelting purity and rolling stability also have a certain influence on the impact performance.In this study,a series of improvement measures were proposed and implemented,including limiting the converter point blowing,shortening the LF refining time to 8‒12 min,increasing the bottom blowing flow to 500-600 L/min,controlling the superheat of continuous casting below 25℃,increasing the rolling temperature to 1220-1230℃,and setting the finishing rolling temperature to 810-850℃.After process optimization,the qualified rate of impact toughness of Q355qD medium-thick plate at‒20℃is increased from 85%to 100%,and the average impact energy is increased by 50 J.

关 键 词：Q355qD中厚板 冲击性能 带状组织 纯净度 轧制稳定性 

分 类 号：TF703.8[冶金工程—钢铁冶金]