The phenomenon of hardness lag of the alloyed Bainite ductile cast iron has been discussed.This phenomenon showed that after the step austempering, the hardness increased with the time.

• 研究了硼、铜、锰对贝氏体球墨铸铁组织和性能的影响，并讨论了球墨铸铁的性能滞后现象，即等温淬火后随时问延长硬度增加的现象。