球墨铸铁原铁液过热温度和保温时间热分析优化控制方法  

Optimal Control Method of the Overheating Temperature and Holding Time for the Base Iron melt of Ductile Iron by Thermal Analysis

作　　者：徐振宇[1] 李大勇[1] 王利华[1] 马旭梁[1] XU Zhen-yu LI Da-yong WANG Li-hua MA Xu-liang(School of Materials Science ＆ Engineering, Harbin University of Science and Technology, Harbin 150040, Heilongjiang, China)

机构地区：[1]哈尔滨理工大学材料科学与工程学院,黑龙江哈尔滨150040

出　　处：《铸造》2017年第2期165-169,共5页Foundry

基　　金：国家自然科学基金(51474082)

摘　　要：优异的原铁液冶金质量是获得良好球化孕育处理效果的基础。本文以铁液中SiO_2-CO脱氧冶金反应分析为主线,利用热分析研究了原铁液最佳过热温度和保温时间控制方法。其步骤包括:(1)按照原铁液化学成分控制范围的中值计算SiO_2-CO脱氧冶金平衡温度T_(eq)和"沸腾"温度T_B,过热温度应选择在尽量接近但不超过T_B;(2)确定过热保温温度后,利用热分析灰口冷却曲线上的共晶凝固特征参量确定最佳保温时间,同时防止碳的过度烧损;(3)对于保温过度的原铁液实施预处理,调节铁液化学成分和石墨形核状态后可恢复到较佳状态;(4)通过最终铁液球化孕育效果检测反推原铁液的冶金质量状态,检验原铁液过热保温优化控制的有益效果。试验结果表明,在球化孕育处理之前,应全面提高原铁液的冶金质量。The excellent metallurgy quality of the base iron melt is the foundation to obtain a good nodularization and inoculation treatment effect. In this paper, the optimal control method of the overheating temperature and holding time for the base iron melt has been studied by thermal analysis based on the SiO2-CO deoxidization metallurgy reaction analysis in the iron melt. The steps included： （1） calculation of the deoxidization balance temperature T^q and ＂boiling＂ temperature TB of the SiO2-CO metallurgical reaction according to the middle value of the basic chemical composition control scopes for the base iron melt, the overheating temperature should be selected in close to but not more than TB as far as possible; （2） after the overheating temperature＇ s selection, some key eutectic solidification characteristic parameters in gray cooling curve were used to determine the optimal holding time, and simultaneously the excessive burning loss of carbon should be prevented; （3） for the base iron melt of over-holding at a chosen heating temperature, a better metallurgical status could be restored by the chemical composition and graphite nucleation condition adjustment through pre-treatment; （4） the metallurgical quality status of base iron melt could be backward deduced through the final nodularization and inoculation effects detection, thereby, the beneficial effect of the optimal control for the base iron melt quality status was checked. The experimental results show that before nodularization and inoculation, the metallurgical quality of the base iron melt for ductile iron preparation should be improved effectively as much as possible.

关 键 词：球墨铸铁 原铁液 过热和保温 热分析 优化控制方法 

分 类 号：TG255[金属学及工艺—铸造]