PLANT FOR CATALYTIC NITRIDING OF STEELS AND ALLOYS IN GAS ATMOSPHERE Russian patent published in 2007 - IPC F27B5/04 C23C8/24 

FIELD: apparatuses for thermo-chemical treatment of steels and alloys in gas media with use of automatic control system.

SUBSTANCE: plant includes heating furnace with muffle or without muffle; unit for catalytic action arranged in furnace in line for feeding technological gases; units for feeding, mixing, proportioning and discharging of technological gases; device for indirect monitoring and controlling nitrogen potential of furnace atmosphere having oxygen sensor, secondary transducer with indication of nitrogen potential in weight units of nitrogen content in iron and actuating organ. Oxygen sensor is in the form solid electrolyte voltage pickup or in the form of semiconductor resistance pickup and it has autonomous thermo-stabilizing system. Unit for catalytic action is in the form of reservoir with catalyst made as tablets of foamed ceramics. Heating furnace is provided with electric heaters or gas burners. Secondary transducer may generate standard outlet signal proportional to predicted concentration of nitrogen in iron. Secondary transducer includes circuit for interpreting outlet signal of oxygen sensor according to binary diagram "iron-nitrogen". Secondary transducer is made with possibility of computer displaying of diffusion processes for graphic indication of phase content, nitrogen concentration and distribution of micro-hardness of diffusion layer in real time.

EFFECT: improved reliability and stability of technological processes, possibility of complex automating of processes.

10 cl, 1 dwg, 1 tbl, 1 ex