厚大断面球墨铸铁铁液石墨畸变倾向预测研究

Study on Prediction of Graphite Degeneration Tendency of Heavy Section Ductile Iron Melt

通过考察不同厚大断面球墨铸铁铁液热分析曲线凝固段及其对应6h凝固组织间的关系,运用模式识别原理和数据库技术,提出了浇注前预测其石墨畸变倾向的方法。结果表明,热分析曲线凝固段综合偏差判据W值与6h凝固组织的石墨形态差异间存在明显收敛关系,当W趋于0时,6h凝固组织石墨形态的差别向0趋于收敛;当W足够小时,两条热分析曲线的差别也足够小,其对应的两种球墨铸铁铁液6h凝固组织中石墨形态的差别也足够小;待评估厚大断面球墨铸铁铁液的石墨畸变倾向可用与其热分析曲线形状最相近的另一铁液的6h凝固组织的石墨形态进行预测。

A method to predict graphite degeneration tendency of heavy section ductile iron melt is put forward based on the pattern recognition of the thermal analysis cooling curves and database technique. Research results show that the difference of every feature of graphite morphology in the samples solidified in 6 hours converges to zero when the comprehensive difference parameter W which presents the difference between thermal analysis cooling curves, approaches zero. And when W of two thermal analysis curves is small enough, the graphite morphologies of the samples that solidify in 6 hours are similar. Therefore, the graphite degeneration tendency of an unknown melt can be showed by the graphite morphology of samples solidified in 6 hours of the melt in the database whose thermal analysis cooling curve freezing zone shape is very close to that of the former.