论文部分内容阅读
为使球铁获得铁素体-珠光体组织以及不同比例的铁素体和珠光体数量,从而获得不同的物理机械性能,退火的规范可以灵活运用,以保证分解不同程度共析渗碳体。因为在A_(cl)以下加热共析渗碳体发生分解和石墨化二个过程,在500℃以下加热组织几乎不变,升至600℃左右时有少量珠光体发生球化和墨化,这一转变首先在铁素体与珠光体交界处,当温度继续升高牛眼铁素体蚕食周围珠光体而扩大,超过650℃石墨化速度大大增加使铁素体失去牛眼形态,但交界处的珠光体由于锰、磷析集仍很稳定,如温度稍超过A_(cl)珠光体将开始转变为奥氏体,所以加热湿度不能超过723℃,随着保温时间
In order to obtain ductile-pearlite ferrite and different proportion of ferrite and pearlite in ductile iron to obtain different physical and mechanical properties, the annealing specification can be flexibly used to ensure the decomposition of eutectoid cementites with different degrees of decomposition. Because below the A_ (cl) heating eutectoid cementite decomposition and graphitization of the two processes below 500 ℃ heated tissue is almost constant, rose to about 600 ℃ when a small amount of pearlite spheroidization and ink, which A change first in the ferrite and pearlite junction, when the temperature continues to increase bovine enamel eroded around the pearlite and expand, more than 650 ℃ graphitization greatly increased the loss of ferrite bovine form, but at the junction Of pearlite due to manganese, phosphorus is still very stable, such as the temperature slightly over the A_ (cl) pearlite will begin to change into austenite, so the heating humidity can not exceed 723 ℃, with the holding time