In the process of cold working, the structure of austenitic stainless steel will transform to martensite, so the stainless steel will have magnetism. In order to completely eliminate the magnetism, high temperature solid solution treatment can be used to restore the stable austenite structure, so as to eliminate the magnetism.

The demagnetization furnace can heat the stainless steel to 1050 ℃ and then quench it with water to eliminate magnetism. The equipment is mainly composed of heating furnace body, stainless steel muffle tank, transmission steel belt and transmission mechanism, etc.; the protective gas adopts liquid ammonia for hydrogen production and purification device. With liquid ammonia as raw material, under the action of catalyst, the mixed gas of hydrogen and nitrogen containing 75% hydrogen and 25% nitrogen can be obtained by heating and decomposition. Gas purifier, used together with ammonia decomposition furnace, can remove residual ammonia and water in mixed gas.