亚温奥氏体化等温淬火球墨铸铁的研究

Study on Austempered Ductile Iron Treated by Intercritical Quenching Process

研究了亚温奥氏体化等温淬火工艺对等温淬火球墨铸铁组织和力学性能的影响。在等温淬火工艺(等温淬火温度370℃,等温淬火时间120 min)一致前提下,当奥氏体化温度在820~880℃区间变化时,随着奥氏体化温度的升高,热处理后组织中针状铁素体的数量愈来愈少;当奥氏体化温度为880℃时,组织已经全部奥氏体化。此外,随着亚温奥氏体化温度的提高,ADI球铁的抗拉强度和硬度呈现逐渐增大的趋势,而伸长率和冲击韧性则逐渐减小。

The effect of intercritical quenching process on the microstructure and mechanical properties of austempered ductile iron was studied.The results show that under the condition of isothermal quenching process(isothermal quenching temperature 370℃,isothermal quenching time 120 min),the increase of austenitizing temperature in the range of 820-880℃will decrease the amount of acicular ferrite in the microstructure;when the austenitizing temperature is 880℃,the microstructure has been austenitized completely.Furthermore,with increasing the austenitizing temperature,the tensile strength and hardness have a ascending trend gradually,while the elongation and impact absorbing energy have a descending trend gradually.