METHOD FOR PRODUCTION OF HIGH-ALLOY COLD-ROLLED ELECTRICAL ISOTROPIC STEEL Russian patent published in 2022 - IPC C21D8/12 C22C38/14 H01F1/147 H01F1/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of ferrous metallurgy, namely to the production of high-alloy cold-rolled electrical isotropic steel used for the manufacture of magnetic circuits of electric machines with high energy efficiency. The method includes the smelting of steel containing, wt. %: less than 0.010 carbon, from 2.5 to 3.5 silicon, from 0.10 to 1.00 manganese, from 0.001 to 0.010 nitrogen, less than 0.015 sulfur, from 0.1 to 2.0 aluminum, less than 0.01 titanium, tin, the content of which depends on the carbon content by the ratio Sn=(8÷12)⋅C, the rest is iron and unavoidable impurities. Continuous casting into slabs, hot rolling of slabs to obtain hot-rolled strips, normalization annealing of hot-rolled strips, their etching, cold rolling to obtain cold-rolled strips, which are subjected to final recrystallization annealing with the application of an insulating coating are carried out. Cold rolling is carried out in two stages with intermediate annealing in a dry protective hydronitric atmosphere, and the final recrystallization annealing of the strip is carried out in a moistened protective hydronitric atmosphere with an oxidative potential value of P(H₂O)/P(H₂)=0.05÷0.20, where P(H₂O) is the partial pressure of water vapor, Pa, P(H₂) is the partial pressure of hydrogen, Pa.

EFFECT: guaranteed low level of specific magnetic losses and high adhesion of the insulating coating is achieved.

1 cl, 1 tbl, 1 ex