NANOCOMPOSITE MARTENSITE STEELS Russian patent published in 2007 - IPC C21D8/00 C22C38/40 C22C38/58 

FIELD: metallurgy industry; production of the high-performance carbon steels.

SUBSTANCE: the invention is pertaining to the field of metallurgy industry, in particular, to production of the high-performance carbon steels. The invention presents the carbon steel and the method of its production. The carbon steel contains the martensite-austenitic grains, the temperature of the beginning of the martensite transformation at least at about 300 °С and the diameter of the martensite-austenitic grains of 10 microns or less, at that each grain has the microstructure containing the martensite laminas alternating with the thin austenitic films with the similar orientation within the limits of the indicated grain limited by then austenitic shell. The method includes: formation of the steel composition with temperature of the beginning of the martensite transformation at least about nearby 300 °С; heating of the indicated steel to the temperature sufficient for its transform into the uniform austenitic phase and transfer of all the alloying components into the soluble state; treatment of the uniform austenitic phase; at that the temperature of the austenitic phase is higher than the temperature of recrystallization of the austenite for production of the size of the grain approximately of 10 micron or less; refrigeration of the uniform austenitic phase in the field of the phase of the martensite transformation for production of the martensite-austenitic grains of approximately 10 microns or less; refrigeration of the austenitic phase in the field of the phase transformation of the martensite for transition into the fusion-spliced martensite-austenitic grains with the diameter approximately of 10 or less with the microstructure containing the laminas of martensite alternating with the thin films of the austenite with the similar orientation within the limits of the indicated grin. The technical result of the invention is production the high-strength corrosion- resistant carbon steel with the heightened stability of austenite.

EFFECT: the invention ensures production the high-strength corrosion- resistant carbon steel with the heightened stability of austenite.

10 cl, 2 dwg