On 2018-08-08 14:48:54
vacuum heat treatment knowledge you need to know
Knowledge you need to know in the vacuum heat treatment process of vacuum heat treatment furnace:
First, when the workpiece is quenched in vacuum, the vacuum quenching oil should be used, which has low saturated vapor pressure.
Second, the movable part of the vacuum heat treatment furnace is all sealed with O-ring, which is cooled by water.
Third, the vacuum heating is mainly radiation, and the distance between the workpieces in the furnace should be kept.
Fourth, nitrogen should not be used as cooling gas when titanium alloy is treated in vacuum heat treatment furnace, because titanium and nitrogen react at high temperature to form golden titanium nitride.
Fifth, the heating temperature of vacuum tempering, vacuum annealing, vacuum solution treatment and vacuum aging is generally the same as that of conventional treatment.
Sixth, in the process of heating up, the workpiece and the material in the furnace will be deflated to reduce the vacuum degree.
Seventh, the vacuum tempering furnace should have quick cooling device. The pressure of cooling water shall be greater than 0.2MPa, and the flow shall be adjustable.
Eighth, cooling gas: generally, 99.995% pure nitrogen is used for steel, 99.999% nitrogen or argon is used for superalloy and 99.995% argon is used for titanium alloy.