“Izhmetmash” JSC (Izhevsk, Russia):

Muradyan O. S., Cand. Eng., Chief Metallurgist, ovanes.muradyan@mail.ru

Scientific and Industrial Enterprise “Gorizont” (Izhevsk, Russia):

Galikeev I. A., Executive Officer

Peculiarities of the process of alloying steel by nitrogen at plasma arc remelting in large-sized furnace are considered. It is shown that nitrogen content in remelted metal increases at the decreasing of total gas pressure inside the furnace. Compositions and mechanical properties of stainless austenite high-nitrogen steels produced using plasma arc remelting furnace, induction furnace in complex with centrifugal casting machine and ladle furnace with preliminary vacuumoxygen decarburisation are presented. As soon as plasma arc remelting furnaces have not been widely used worldwide, while expenses for ingot production via this method are essentially higher than via single-stage production, it is expedient to use such furnaces onle for manufacturing of the components of responsible usage, where high purity of non-metallic unclusions, isotropy of properties and homogeneity of chemical composition. In this connection, the process including melting od semiproduct in an arc furnace, vacuum-oxygen decarburization in a ladle and lafle furnace finishing has been tested for production of non-magnetic heavy drilling tubes. Alloying by nitrogen has been conducted by transfer of nitrogenized manganese in a ladle furnace at the atmospheric pressure. As soon as this process can be hold at relatively low temperature and nitrogen bubbles forming is accompanied with obstacles, nitrogen content in the alloy exceeded substantially its standard solubility. Produced steels after hot deformation satisfied all requirements of petroleum standards. strength properties of centrifugal casted tubes were slightly lower.

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