Q345E钢0800 mm铸坯表面网状裂纹的分析及控制措施

特殊钢 ›› 2018, Vol. 39 ›› Issue (3): 43-46.

Q345E钢0800 mm铸坯表面网状裂纹的分析及控制措施

陈远清^1,2, 仇圣桃¹, 李刚², 陈树军², 汪德伟²

1钢铁研究总院连铸技术国家工程研究中心，北京100081 ；
2张家港联峰钢铁研究所有限公司,张家港215628

收稿日期:2018-01-03 出版日期:2018-06-01 发布日期:2022-06-02
作者简介:陈远清(1981-)，男，博士研究生，高级工程师,2004年重庆大学(本科)毕业，炼钢及连铸工艺技术研究和特殊钢产品开发°

Analysis on Surface Net Cracks of C>800 mm Casting Bloom of Steel Q345E and Control Measures

Chen Yuanqing^1,2 , Qiu Shengtao¹, Li Gang², Chen Shujun² , Wang Dewei²

1 National Engineering Research Center for Continuous Casting Technology, Central Iron and Steel Research Institute,Beijing 100081;
2 Zhangjiagang Lianfeng Iron and Steel Research Institute Co Ltd, Zhangjiagang 215628

Received:2018-01-03 Published:2018-06-01 Online:2022-06-02

摘要/Abstract

摘要： 采用金相显微镜和扫描电镜分析了Q345E钢Φ800 mm铸坯（/%:0.15C,0.27Si,1.37Mn,0.009P,0.001S,0.03Nb,0.04V,0.030A1,0.008 ON）表面网状裂纹,得出结晶器壁和凝固坯壳之间保护渣膜厚度不均匀,使坯壳局部受挤压,产生凹坑,冷却速度降低,产生热应力裂纹。通过将保护渣碱度（CaO）/（SiO₂）从1.03提高到1.15,熔点从1 235℃降至1 210℃,1 300℃粘度从0.87 Pa·s提高到1.10 Pa·s,使Φ800 mm连铸坯表面凹坑和网状裂纹的发生率从原60.5%降至0.5%以下。

Abstract: The surface net cracks of Φ 800 mm casting bloom of steel Q345E (/% : 0.15C, 0.27Si, 1. 37Mn, 0. 009P, 0. 001S, 0. 03Nb, 0. 04V, 0. 030Al, 0.008 ON) have been analyzed by metallurgy and scanning electron microscope. It is obtained that the uneven thickness of flux film in between mold wall and solid shell leads to extruding local shell, forming depression, decreasing cooling rate and forming thermal stress cracks. With increasing basicity of mold powder (CaO)/(SiO₂) from 1. 03 to 1.15, decreasing melting point form 1 235 °C to 1 210 °C , and increasing viscosity at 1 300 °C from 0. 87 Pa · s to 1. 10 Pa· s, the occurring rate of surface depression and net cracks of 0800 mm casting bloom decreases from original 60. 5% to less than 0. 5%.

Key words: Steel Q345E, , Φ 800 mm Casting Bloom, Net Cracks, Depression, Mold Powder

陈远清, 仇圣桃, 李刚, 陈树军, 汪德伟. Q345E钢0800 mm铸坯表面网状裂纹的分析及控制措施[J]. 特殊钢, 2018, 39(3): 43-46.

Chen Yuanqing, , Qiu Shengtao, Li Gang, Chen Shujun , Wang Dewei. Analysis on Surface Net Cracks of C>800 mm Casting Bloom of Steel Q345E and Control Measures[J]. Special Steel, 2018, 39(3): 43-46.