Patent ID: 9464346
Filing Date: 2016-10-11
CPC Classification: C23C

Claim Text:
1. A method of cooling metal parts that have been subjected to a molten salt bath nitriding/nitrocarburizing treatment in a treatment station, comprising: arranging a cooling chamber in direct overlying relation with the treatment station, before an end of said treatment, filling the cooling chamber, With refrigerant in liquid form, volume expansion as the refrigerant evaporates discharging oxygen from the cooling chamber to create an inert atmosphere within the cooling chamber, transferring vertically all the treated parts from the treatment station directly into the inert atmosphere within the cooling chamber, closing the chamber, leaving the parts in the chamber for a preset length of time to reach a temperature at which salt congeals and forms a protective barrier, and removing the parts from the chamber and then subjecting the parts to a rinsing operation, whereby the cooling method results in parts exhibiting no trace of surface oxidation.