METHOD OF MANUFACTURE OF LOW-ALLOY STEEL STRIPS Russian patent published in 2018 - IPC C21D8/02 C22C38/38 

FIELD: technological processes.

SUBSTANCE: invention relates to the production of sheet steel from strip steels. Method comprises heating slabs, their rough rolling to intermediate thickness and temperature, finishing rolling with a regulated rolled strip, the number of finishing passes and regulated temperature at the beginning and end of finishing rolling. Thickness of tackle NP for finishing rolling satisfies the condition: -0.7857×Ng²+19.414×Ng-73.2≥(Np)≥-Ng²+24×Ng-95.4, where Ng is the thickness of the finished strip, the start temperature of the finish rolling Tn=(1.4286×Ng²-40.571×Ng+1208)±10 °C, the end of the finish rolling Tk=(0.7143×Ng²-17.286×Ng+944)±10 °C, rolling is carried out in no less than 5 finishing passes with a minimum compression of at least 10 % per pass, with the exception of a smoothing pass, providing a ferrite-bainite structure with a grain size of ferrite of no more than 11 and 12 points at the surface and in the middle part of the sheet, respectively, while using slabs of low-alloyed steel of a regulated chemical composition.

EFFECT: improvement of the complex of mechanical properties and cold resistance of steel without additional heat treatment to produce hot rolled steel with a ratio of yield strength to temporary resistance of not more than 0,90.

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