摘要
建立二维非稳态传热模型对380 mm×490 mm大方坯凝固过程进行了模拟计算,并采用射钉试验结果验证了该模型的准确性。计算结果表明,拉速对凝固终点影响最大,过热度和比水量影响较小。拉速每增加0.01 m/min,凝固终点后移约0.5 m;过热度每增加10℃,凝固终点后移约0.3 m;比水量每减少0.02 L/kg,凝固终点后移约0.15 m。在固相率较低时进行大压下,铸坯中心质量并未改善,同时会产生2.0级的中间裂纹。通过调整拉速,在较高固相率时进行大压下,铸坯中心偏析由2.0级改善到0.5级,中心疏松和缩孔降到0.5级,并且消除了内部裂纹。
A two-dimensional non-steady-state heat transfer model was established for the working conditions of bloom GCr15 with the section size of 380 mm × 490 mm,and the verification was made on the basis of the pin penetration tests.The calculation results have shown that the solidification end significantly influenced by casting speed,while the effects of superheat and specific water are much lower than casting speed.The solidification end will fluctuate about 0.5 m if casting speed varies 0.01 m/min.However,the distance of solidification endpoint from meniscus will increase 0.3 m if superheat increases 10℃.By comparison,the distance increases only 0.15 m if specific water decreases 0.02 L/kg.The internal quality of bloom was not improved when heavy reduction was applied at lower solid fraction,and resulting serious internal cracks with the grade 2.0.By adjusting the casting speed,heavy reduction was applied at higher solid fraction.Center segregation grade was remarkably reduced from 2.0 to 1.0,center porosity grade and shrinkage cavity grade were significantly decreased to 0.5,and the internal cracks was eliminated.
出处
《钢铁》
CAS
CSCD
北大核心
2018年第1期41-45,71,共6页
Iron and Steel
基金
国家科技支撑计划资助项目(2012BAE03B01)
关键词
传热
凝固终点
大压下
连铸
大方坯
heat transfer
solidification end
heavy reduction
continuous casting
bloom
