METHOD OF PRODUCING HOT-ROLLED COLD-RESISTANT ROLLED STOCK RESISTANT TO ATMOSPHERIC CORROSION Russian patent published in 2024 - IPC C21D8/02 C22C38/50 C22C38/42 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to production of hot-rolled products from low-alloy steel, intended for construction industry, bridge building, landscape structures, transport machine building, road and mining equipment, which are also used in Arctic regions. Steel is continuously cast into slabs, wherein steel has chemical composition containing, wt. %: C 0.09–0.12; Si 0.40–0.60; Mn 0.70–1.20; Cr 0.60–0.80; Ni 0.30–0.60; Cu 0.20–0.40; Al 0.020–0.060; Ti 0.010–0.030; P 0.060–0.080; S not more than 0.003; N not more than 0.007; Fe is the rest. Chemical composition of steel is selected depending on the minimum corrosion resistance index (I), the value of which corresponds to the condition: I=26.01(%Cu)+3.88(%Ni)+1.20(%Cr)+1.49(%Si)+17.28(%P)-7.29(%Cu)(%Ni)-9.10(%Ni)(%P)-33.39(%Cu)²≥6. Slabs are heated, subjected to controlled rolling and accelerated cooling to coiling temperature, coiled into rolls followed by slow cooling in air. Finish rolling end temperature is set not less than 870 °C, and the coiling temperature is selected in range of 480–540 °C.

EFFECT: obtaining rolled products with high level of mechanical characteristics, resistant to atmospheric corrosion and having cold resistance to minus 40 °C.

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