低温铸态无Ni球墨铸铁的试验研究

摘要

Under the process of scrap steel recarburizing, the effects of chemical composition, the process of spheroidizing and inoculation on mechanical properties, low temperature property and metallurgical structures of low temperature as-cast ductile iron were investigated in this paper. The results show that under scrap steel recarburizing process and 3.4%-4.0% C, 1.7%-2.2% Si, the low temperature impact energy ≥ 12 J and ≥ 10 J at -20 ℃ and -40 ℃ respectively, the compound inoculation process such as ladle bottom compound spheroidizing, bottom inoculation, tapping and pouring metal-stream inoculation made spheroidizing grade reach grade 2, F> 90%, graphite dimension 90% VI6+10% V5.%研究了在废钢增碳工艺条件下,化学成分、球化及孕育对低温球墨铸铁铸态力学性能、低温性能及金相组织的影响.结果表明:废钢增碳条件下,成分为3.4％～4.0％C,1.7％～2.2％ Si时,-20℃低温冲击吸收功≥12 J,-40℃时≥10J;采用包底复合球化、包底孕育、出铁随流孕育、浇注随流孕育的复合孕育工艺使材质金相组织球化达到2级,石墨大小6级90％、5级10％,铁素体＞90％.