PURPOSE: To provide an active nitrogen adsorbing catalyst which consists of a porous metallic body of three-dimensional irregular aggregate of metallic fibers made of FE type alloys, is highly productive, does not require excess heat energy and is used at heat treatment of metallic materials.
CONSTITUTION: In the case of subjecting metallic materials to bright heat treatment in a reducing ammonia decomposing gas atmosphere, alloys of Fe, Al, Ti, B, Si, etc. of high affinity to nitrogen are filled in a heat treatment furnace, and a gas is flowed therein. Atomic nitrogen is bound with the alloys and the stable gaseous atmosphere without containing nitrogen of high activity is supplied. At this time, in order to decrease the pressure drop of the catalyst bed filled with the alloys owing to the passage of the gas and to increase contact area, the three-dimensional irregular aggregate A of metallic fibers 1 made of Fe type alloys contg. 1≥ kinds of the above-described alloys is used.
NISHIMOTO TATSUYA
SATOUNE TOSHIHIKO
