钡、钙在大断面球铁中抗衰退作用研究

Study of Anti failling Role of Ba and Ca in Heavy Section Ductile Iron

试验以武钢生铁为原料，研究了含Ｂａ稀土镁球化剂及含Ｂａ、Ｃａ、Ａｌ硅铁孕育剂和瞬时孕育方法在大断面铸态铁素体球铁中的抗球化衰退作用．实验表明，采取上述措施完全消除了大断面球铁的碎块状石墨，使壁厚为２５０ｍｍ～５００ｍｍ试块心部球化率达到８５％以上，机械性能σｂ＞３００ＭＰａ，δ＞９％，并用Ｂａ、Ｃａ形成硫化物及氧化物的热力学稳定性及Ｂａ、Ｃａ对包围石墨球的奥氏体壳的稳定性对抗衰退作用进行了分析和讨论．

By using Wugang pig iron as raw matrial, anti failling role of spheriodizing agent containing Ba, inoculater containing Ba, Ca and Al and instantaneous method in heavy section as cast ferritic ductile iron are studied in this paper. Experiments show that the chunky graphite has been completely removed by taking above steps. Spherical rate in heavy section ductile iron′s core is over 85%. As for mechanical properties. σ b is more than 300 MPa, δ more than 9%. Thermodynamics stability of sulphide and oxide of Ba and Ca and effect of Ba and Ca on astenite stability are used to discuss and analyze the anti failling role.