Heat-treated materials used alloying elements on the protection of high-temperature alloys heat treatment furnaces for heat treatment. Because whether it is modern superalloy matrix elements which are complex alloy system , they use solid solution strengthening , the second phase strengthening and grain boundary strengthening alloy intensive three means . Therefore, a thermal treatment furnace in the atmosphere of air can be used to protect the atmosphere , an inert gas and nitrogen gas and a vacuum furnace . Protective atmosphere heat treatment furnace protective atmosphere should be used diluted exothermic , endothermic protective atmosphere should not be used because the endothermic atmosphere has the effect of carburizing .

When using an inert gas as the atmosphere heat treatment furnace , the heat treatment atmosphere at the inlet of the device should be lower than the dew point -50 ℃. While the use of nitrogen as a protective atmosphere heat treatment furnace , high purity nitrogen should be used (≥ 99.99%). Due to the high temperature nitrogen with increasing nitrogen effect , when used as a protective atmosphere of nitrogen , allowing only used at temperatures no higher than 770 ℃ .

Vacuum furnace heating time, to fully consider the alloy alloying elements vapor pressure, vacuum pressure should take into account when choosing neither consider oxidation and decarbonization , without generating depleted of alloying elements .