ISSN:1003-8620

CN:42-1243/TF

主管:中信泰富特钢集团股份有限公司

主办:大冶特殊钢有限公司

特殊钢 ›› 2015, Vol. 36 ›› Issue (6): 30-32.

• 工艺技术 • 上一篇    下一篇

Q235B和Q345B钢中厚板表面纵裂纹的成因分析和工艺优化

陈振业1,张阔斌2,王云阁3,尹绍江3,李建新1,刘铁力2   

  1. 1河北钢铁技术研究总院,石家庄052165 ;
    2唐山中厚板材有限公司,唐山063000;
    3河北钢铁集团唐山钢铁有限责任公司技术中心,唐山063000
  • 收稿日期:2015-06-15 出版日期:2015-12-01 发布日期:2022-08-12
  • 作者简介:陈振业(1983-),男,硕士(2009年武汉科技大学),工程师, 2006年武汉科技大学(本科)毕业,中厚板质量控制、新产品和工艺开发。

Analysis on Formation of Surface Longitudinal Crack of Steel Q235B and Q345B Medium-Heavy Plate and Process Optimization

Chen Zhenye1, Zhang Kuobin2, Wang Yunge3, Yin Shaojiang3, Li Jianxin1,Liu Tieli2   

  1. 1 Centre Iron and Steel Technology Research Institute , HBIS, Shijiazhuang 052165;
    2 Tangshan Medium-Heavy Plate Co Ltd, Tangshan 063000;
    3 Technical Center, Tangshan Iron and Steel Co Ltd, Hebei Iron and Steel Group, Tangshan 063000
  • Received:2015-06-15 Published:2015-12-01 Online:2022-08-12

摘要: Q235B钢(/%:0.14~0.17C,0.30~0.60Mn,0.010~0.040Als)和Q345B钢(/%:0.15~0.18C,1.30~1.60Mn,0.010~0.040Als)100 mm厚板的生产流程为铁水预处理-120 t转炉-LF-200 mm板坯连铸-轧制工艺。通过分析得出中厚板表面纵裂纹源于铸坯裂纹。通过保护渣碱度由1.16提高至1.26,1300℃黏度由0.80Pa·s提高至0.97 Pa·s,软搅拌时间不低于10 min,拉速控制在1.0 m/min左右,液面上下波动≤5 mm,保持结晶器锥度9.0 mm,钢水过热度20~25℃,二冷水为0.662 L/kg等工艺措施,使Q235B和Q345B钢中厚板纵裂率由2.17%下降至1.08%,板材综合合格率由原94.78%提高到98.16%。

关键词: 中厚板, Q235B和Q345B钢, 纵裂纹, 铸坯, 工艺优化

Abstract: The flowsheet of 100 mm heavy plate of steel 235B (/% : 0.14 ~0.17C, 0. 30 ~ 0.60Mn, 0.010 ~ 0. 040Als) and steel Q345B (/% : 0. 15 ~0.18C, 1. 30 ~1. 60Mn, 0. 010 ~ 0. 040Als) is hot metal pretreatment-120 t converter-LF-220 mm slab casting- rolling process. By analysis it is obtained that the surface cracks of medium-heavy plate originate from cracks of casting slab. With using the process measures including increasing basicity of mold shielding slag from 1.16 to 1. 26, increasing its viscosity at 1 300 °C from 0. 80 Pa·s to 0. 97 Pa·s, soft stirring time no-less than 10 min, controlling casting speed about 1. 0 m/min; liquid surface up and down ≤5 mm; maintaining mold cone 9. 0 mm; liquid superheat extent 20 ~25 °C and secondary water rate 0. 662 L/kg, the ratio of longitudinal cracks of steel Q235B and Q345B medium-heavy plate decreases from original 2.17% to 1. 08% , and the comprehensive qualified ratio of plate products increases to 98. 16% from original 94. 78%.