摘要
建立了考虑δ/γ相变的GCr15轴承钢大方坯连铸凝固两相区溶质微观偏析模型,并应用于220 mm×260 mm铸坯的凝固传热。结果表明:通过模型可以获得高碳钢精确的固液相线温度,以及温度与固相率的关系;GCr15轴承钢大方坯凝固过程仅析出γ相,凝固末期S、P和C元素的偏析严重;固相率越大,冷却速率对偏析度的影响更明显;S和P元素含量以及冷却速率对零塑性温度(ZDT)影响较大;采用基于凝固传热模型优化的连铸工艺后,铸坯中心碳偏析指数控制在0.96~1.05,且铸坯未产生内裂纹。
A micro segregation model of solute elements in the mushy zone in continuously cast bloom of bearing steel GCr15 is established in consideration ofδ/γphase transformation,which is applied in the solidification heat transfer of220 mm×260 mm continuous casting bloom.The results show that accurate solidus and liquidus temperature and relationship between temperature and solid fraction during the solidification process of high carbon steel can been acquired by the model;onlyγphase precipitates out from liquid steel directly during the solidification process of bearing steel GCr15;the segregation ratio of S,P and C is bigger at the final solidification stage;as solid fraction increases,the effect of cooling rate on segregation is more remarkable;the content of S,P and cooling rate have a bigger effect on ZDT.After the continuous casting process parameters optimized based on the solidification heat transfer model,the center carbon segregation ratio is0.96 to 1.05 and the internal cracks don’t appear.
作者
安航航
张国锋
武佳毅
张龙
An Hanghang;Zhang Guofeng;Wu Jiayi;Zhang Long(Collaborative Innovation Center for Common Technology of Iron and Steel,Beijing University of Science and Technology,Beijing 100083;Lingyuan Iron and Steel Co Ltd,Lingyuan 122500;Inner Mongolia University of Science and Technology,Baotou 014010)
出处
《特殊钢》
2021年第3期16-20,共5页
Special Steel
基金
中央高校基本科研业务费专项资金项目(FRF-TP-20-029A1)。
关键词
GCr15轴承钢大方坯
微观偏析模型
溶质元素分配
高温力学性能
中心碳偏析
GCr15 Bearing Steel Casting Bloom
Micro Segregation Model
Solute Redistribution
High-Temperature Mechanical Properties
Center Carbon Segregation
