稀土镍铜奥氏体球铁的研究

Study on Ni-Cu Austenitic Ductile Iron Treated with Rare-earth

研究中发现，与国外有关铈对奥氏体铸铁球化有害的论断不同，单用铈混合稀土也能制取球铁，但白口倾向大、石墨球形差。还发现，用稀土处理奥氏体铸铁，不导致游离铜相出现。在此基础上，通过研制复合球化剂、调整铁水成分、净化铁水、加强孕育等措施，改善了稀土球铁的石墨形态、克服了白口倾向，研制出稀土镍铜奥氏体球铁。该球铁力学性能与ＩＳＯＳ－ＮｉＣｒ２０２相同，耐海水腐蚀性更好，且生产成本较低。

Contrary to opinion reported abroad on the detriment of cerium to nodularization of austenitic cast iron, the spheroidal graphite cast iron can be obtained with treating molten iron by mixed Ce rare-earth, while it caused high chilling tendency and increased irregularity of graphite shape. It was found that no dissociated. Cu-phase occured in NiCu austenitic ductile iron treated using rare-earth. Based on the investigation, through developing composite spheroiditic agent, adjusting chemical compostition of iron melt, purifying melted iron and improving inoculation, the better regularity of graphite shape was obtained the chilling tendency was overcome, thus manufacturing Ni-Cu austenitic ductile iron treated using rare-earth, the mechanical prpperties of which is the same as that of ISO S-NiCr202,its seawater corrosion resistance is higher than that of S-NiCr202 and has low production cost.