Chromium-manganese stainless steels with nitrogen content up to 2.10 wt%

This paper presents the possibilities of existent in the Institute of metal science (Sofia) plants for nitrogen alloying of corrosion resistant steels type CrMnMo21 18 3 with nitrogen content up to 2.10 wt%. The method of producing is with only one melting of the charge without an additional electroslag remelting under pressure (ESRP). It is used the combination method for nitrogen alloying of the melt by solid nitrogen carrier and nitrogen gaseous blowing under high pressure up to 8 MPa. It has been obtained the compact and homogeneous ingots (10 kg of each). It is proved the possibilities for producing of industrial 0.5 and 1.8 t ingots of these grades steels with nitrogen content up to 1.20 wt percentage. All ingots of both nitrogen content levels were plastic deformed by forging and rolling. The industrial ingots were forged on radial forging machine CFM-SH 500 and laboratory ingots were deformed on laboratory rolling mill quarto in IMS. After high temperature quenching (1473-1523 K; water) the high nitrogen steels have shown a very good complex of mechanical properties: yield strength (R0.2): 750-1000 MPa, tensile strength (Rm):1250-1500 MPa, relative reduction of area (Z):60-50%, Rockwell hardness : 30-50. (orig.)