There are two misunderstandings in the analysis of carburization phenomenon of vacuum heat treatment workpiece: first, it is believed that the workpiece is carburized in quenching oil; second, it is believed that the graphite parts in the heating chamber cause carburization. In fact, in many cases, it is not these two reasons, but the cleanliness of the heating chamber is not high. There is a large amount of quenching oil in and out of the furnace, in and out of the material basket, in and out of the feeding trolley into the hot chamber, which remains on the cold wall of the hot chamber. When heating, a volatile reduction atmosphere is formed to increase the carbon of the workpiece.
In addition to 1050 ℃ high temperature above the temperature directly into the oil. When the heated workpiece oil below 1050 ℃ is quenched, a little precooling will not cause obvious carburization.
The carburization of the graphite parts in the heating chamber can not be eliminated, but there is no serious residual quenching atmosphere.
The carburization phenomenon of vacuum heating quenching is more serious because the quenching oil pollutes the furnace, not because of the oil quenching or graphite parts!
On 2018-08-08 11:45:46
