低温铁素体球墨铸铁的生产与研究

Production and Research on Low-Temperature Ferrite Nodular Iron

介绍了低温铁素体球铁的发展概况,阐述了生产-40℃、-50℃低温球铁的生产要点,并对低温铁素体球铁的力学性能进行试验研究,研究表明:(1)温度降至-20℃时,韧-脆性转变速度不变或变化很小,但温度降至-40℃、-50℃、-60℃时,韧-脆性转变对应于温度的应变速率都会出现大幅度的提高;(2)FATT50与技术标准最低要求的冲击功12 J之间并不存在直接的关系;(3)将-40℃QT400-18AL、-50℃QT400-18AL低温铁素体球墨铸铁技术标准的冲击功定为12J,能使低温球铁的冲击性能可靠地控制在韧性断裂区域;(4)试验表明,-60℃QT400-18AL也能稳定生产。

The development situation of low temperature ferrite nodular iron was introduced. The key points to produce-40 ℃and-50 ℃ low temperature nodular iron were described and an investigation on the mechanical properties of low temperature ferrite nodular iron was conducted. The result of investigation showed:(1)When temperature decreased to-20 ℃,the transition rate from toughness to brittleness was constant or very small;however when temperature deceased to-40 ℃、-50 ℃、-60 ℃,the transition rate from toughness to brittleness corresponding to the temperature was increased in large scale.(2)There was no direct relationship existing between the FATT50 and the technical standard-required minimum impact energy of 12 J.(3)By prescribing12 J as the required impact energy in the technical standard of-40 ℃ QT400-18 AL,-50 ℃ QT400-18 AL grades low temperature ferrite nodular iron,it's possible to control reliably the impact property of low temperature nodular iron in the tough fracturing range.(4)Experiment showed that even-60 ℃ QT400-18 AL grade low temperature nodular iron could be produced stably.