包晶钢Q235D连铸大方坯角裂研究及工艺优化
Research of Ttransverse Corner Crack and Process Optimization of Continue Casting for Peritectic Steel Q235D Bloom
姚成功1， 袁守谦1， 陈 列2， 王治钧1
点击：3644次 下载：0次
作者单位：（1. 西安建筑科技大学 冶金工程学院，陕西 西安 710055；2. 西宁特殊钢股份有限公司 技术质量中心，青海 西宁，810005）
中文关键字：包晶钢； Q235D； 连铸； 角部横裂； 三角口
英文关键字： peritectic steel; Q235D; continuous casting; transverse corner crack; triangular gaps
中文摘要：Q235D属于包晶钢范畴，因此在连铸生产过程中不可避免的会遇到包晶钢连铸的普遍性缺陷。西宁特钢采用60 t consteel EBT-LF（VD）-CC的工艺生产Q235D连铸大方坯（250 mm × 280 mm），在生产中存在的主要问题是角部横裂，最终反映到轧材上为棒材（?准130 mm）表面的顺裂和三角口缺陷。为消除由于连铸坯角部横裂而产生的缺陷，通过对连铸包晶钢裂纹形貌、组织和裂纹形成机理的研究。对连铸过程的以下参数：钢水成分、钢水过热度、各种渣料的选择、各段冷却水量、拉坯速度和电磁搅拌参数进行优化，最终达到消除铸坯角部横裂、优化成材性能的目标。
英文摘要：Q235D is one kind of peritectic steel, so the casting production inevitably encounters the universality defects of peritectic steel casting. Cast bloom(250 mm × 280 mm) of Q235D is produced by 60 t consteel EBT-LF(VD)-CC flow sheet at Xining Special Steel. The main problems in the production are transverse corner crack, the cracks and "triangular gaps" at surface of 130 mm round bar occur after rolling. In order to eliminate the defects caused by transverse corner crack of bloom, the morphology and microstructure and principle of crack formation was researched. The following parameters in the continuous casting process were optimized: the composition and superheat of liquid steel, the choice of various slags, the different of cooling water amount, the casting speed and electromagnetic stirring parameters. Finally the cracking defects of the bloom is eliminated, and the quality of the bar is optimized.