METHOD OF CRYOGENIC-DEFORMATION PROCESSING OF STEEL Russian patent published in 2009 - IPC C21D8/00 C21D6/04 C21D6/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, namely to the methods of processing noncorrosive austenitic steel grades and can be used, for instance for manufacturing heavy duty parts for the machine building industry. The method involves making austenitic steel containing components in the following ratio, wt %: carbon 0.01-0.25; chromium 13.0-18.0; nickel 8.0-18.0; aluminium 0.1-3.0; titanium 0.1-3.0; manganese up to 0.3; silicon up to 0.3; molybdenum up to 0.2; copper up to 0.2; sulphur up to 0.03; phosphorus up to 0.03; iron and unavoidable impurities are the rest, if the following conditions are met: the total amount of aluminium and titanium is 0.5-3.2; quenching, plastic deformation at cryogenic temperatures by several steps with the total degree of deformation being 60-97%, backing after each step and high-temperature tempering on the final stage of the processing of the billets. Moreover, the method involves backing at a temperature of 150-200°C, high-temperature tempering at 480-550°C, plastic deformation by means of rolling with the total degree of deformation being 60-90%, plastic deformation by means of drawing with the total degree of deformation being 60-97%.

EFFECT: nanocrystalline structure of the austenitic steel ensuring high strength properties, a low level of internal microstresses and a high maintainability of the parts.

4 cl, 2 ex, 3 tbl