高端塑料模具钢铸坯表面裂纹缺陷分析与保护渣优化  

Analysis of surface cracks and optimization of mold flux for advanced plastic mold steel slab

作　　者：刘志远[1] 王重君 栾文林[1] 贾永杏 吴东阳 杨全海 LIU Zhiyuan;WANG Chongjun;LUAN Wenlin;JIA Yongxing;WU Dongyang;YANG Quanhai(Tangshan Heavy Plate Co.,Ltd,Hebei iron and Steel Group,Tangshan 063000,Hebei,China)

机构地区：[1]唐山中厚板材有限公司炼钢部,河北唐山063000

出　　处：《连铸》2024年第2期91-96,110,共7页Continuous Casting

摘　　要：针对高端塑料模具钢在连铸过程中出现的铸坯表面裂纹缺陷,对铸坯表面裂纹进行分析,判断为保护渣性能引起。采用正交试验设计不同基料配方保护渣方案,通过检测保护渣的成分、熔点、熔速、黏度和结晶特性进行保护渣分析,设计方案中保护渣半球温度范围为1 030~1 179℃、黏度0.085~0.127 Pa·s;优化后的保护渣碱度略有降低、结晶温度和凝固温度降低、润滑性提高。对保护渣进行矿相分析,由结晶图可以看出,优化后的保护渣的结晶晶体尺寸均匀,主要以长石类晶体为主、且有少量玻璃体存在,可以改善保护渣的传热和润滑效果。通过对保护渣性能进行优化,铸坯表面裂纹缺陷得到有效控制,由10%降低到0.2%以下。Aiming at the surface crack defects of advanced plastic mold steel during the continuous casting process,sampling analysis was conducted on the surface cracks of the casting slab,and it was determined that they were caused by the performance of the mold flux.Orthogonal experiments were used to design different base material formulas to design a mold flux plan.The composition,melting point,melting rate,viscosity,and crystallization characteristics of the mold flux were analyzed.The hemispherical temperature range of the mold flux in the design plan was 1030-1179 ℃,and the viscosity was 0.085-0.127 Pa·s.After optimization,the alkalinity of the mold flux is slightly reduced,the crystallization temperature and solidification temperature are reduced,and lubrication is increased.The melting point and viscosity of the mold flux are reduced,and the melting effect is improved through mineral phase analysis of the mold flux,it can be seen from the crystal diagram that the optimized mold flux uniform crystal size,mainly composed of feldspar like crystals,and a small amount of glass body exists,which can improve the heat transfer and lubrication effect of the mold flux.By optimizing the performance of the mold flux,the surface crack defects of the casting slab were effectively controlled,reducing from 10%to below 0.2%.

关 键 词：中厚板 塑料模具钢 铸坯 表面裂纹 保护渣 析晶矿相 

分 类 号：TF777[冶金工程—钢铁冶金]