Steel foil carbon determination protection valve of carburizing furnace

The utility model discloses a steel foil carbon determination protection valve of a carburizing furnace. The steel foil carbon determination protection valve of the carburizing furnace comprises a ball valve switch, a water cooling nitrogen protection chamber and a carbon determination bar, one end of the water cooling nitrogen protection chamber is connected with the ball valve switch through a connecting piece, the end of the carbon determination bar provided with a piece of carbon determination steel foil enters the end of the water cooling nitrogen protection chamber opposite to the ball valve switch, the carbon determination bar is hermetically connected with the end of the water cooling nitrogen protection chamber through a hermetical connecting assembly, and the inner diameter of the ball valve switch is larger than the maximum outer diameter of the carbon determination bar. The protection valve uses cooling medium to quickly cool the carburized high-temperature steel foil, nitrogen protects the high-carbon content steel foil in the cooling process and seals the cooling chamber in the cooling process so as to realize the quick and non-oxidation cooling in the steel foil carbon determination of the carburizing furnace, the weighing precision is guaranteed after the steel foil is carburized, and accordingly the atmosphere of carbon potential in a high-temperature atmosphere furnace is precisely and actually reflected, and the batch quality problem of the carburized workpieces is reduced.