我厂长期以来一直采用以煤油作渗碳剂的气体渗碳工艺,产品质量稳定可靠。可是,有一段时间发现齿轮渗碳直接淬火后,挂具上面一层齿轮硬度往往偏低。经仔细查找原因,发现是由于碳黑附庄零件表面,且出炉后表面温度迅速降低,所以淬火后硬度 Our factory has long been using carburizing carburizing gas carburizing process, product quality is stable and reliable. However, for a period of time, it was found that the gear hardness of the gear above the hanger tends to be low after direct quenching of the gear carburizing. After careful examination of the cause, it was found that due to the carbon black attached to the surface of the part, and the surface temperature was rapidly reduced after being baked, the hardness after quenching