Drop hardening: the process of dropping small cups and cones and all rollers directly from the drop hardening furnace into an oil bath which quenches them.
是指将小尺寸的外圈，内圈和所有滚动体直接从熔炉里抛到冷却油中进行淬火的工艺过程。
2
By measuring the cooling curve and quench severity of quenching oil at various flow rates, the relationship among the hardening capacity, quench severity and flow rate was established.