STEEL ARTICLE WITH HIGH TEMPERATURE OF AUSTENITIC GRAIN ENLARGEMENT AND METHOD OF ITS PRODUCTION Russian patent published in 2011 - IPC B22D11/06 

FIELD: process engineering.

SUBSTANCE: proposed article comprises less than 0.4 wt % of carbon, less than 0.06 wt % of aluminium, less than 0.01 wt % of titanium, less than 0.01 wt % of niobium, less 0.02 wt % of vanadium, and includes particles of silicon and iron oxides distributed in steel microstructure. Mean size of oxide particles makes less than 50 nm, for example, its varies from 5 to 30 nm. Fine oxide particles distributed in microstructure may constrain ferrite recrystallisation at deformation to, at least, 10.0% and temperatures approximating to 750°C in holding for up to 20 minutes. Steep article may be produced by continuous casting of steel tape between casting rolls from molten carbon steel wherein total oxygen content makes, at least, 70 ppm and that of free oxygen makes 20 to 60 ppm. Preferably, content of total oxygen makes less than 250 ppm while that of free oxygen varies from 20 to 60 ppm. With casting rolls revolving, molten steel gets hardened to form crusts on roll surfaces with the content of oxide inclusions that reflects the content of total oxygen in molten steel.

EFFECT: higher strength and impact viscosity of steels.

53 cl, 23 dwg, 1 ex, 3 tbl