METHOD OF PRODUCING HIGH-NITROGENOUS AUSTENITE STEEL POWDER OF NANOCRYSTALLINE STRUCTURE Russian patent published in 2013 - IPC C22C33/02 B22F3/18 B22F1/00 

FIELD: metallurgy.

SUBSTANCE: mix of chromium, nickel, manganese and iron is prepared and placed into metallic flow reactor of high-duty vibrating mill equipped with gas flow system. Grinding balls are added to fill 30-50% of reactor volume. Said reactor is sealed to blow said mix by nitrogen-bearing gas at the rate of 2-16 l/h for 10-20 minutes. Then, gas flow rate is reduced to 0.2-0.3 l/h to subject said mix to mechanical alloying with power dose of 15o-720 kJ/g. Reactor is completely sealed and subjected to fast cooling. Polymethyl methacrylate in amount of 1-3% of powder weight is added thereto, reactor is closed to perform extra mechanical alloying for 10-15 minutes. Now, powder is withdrawn and placed into stainless steel tube to catty out hot rolling with reduction to 80-90% and annealing with fast cooling.

EFFECT: higher mechanical properties.

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