METHOD OF PRODUCING BORON-CONTAINING STEEL Russian patent published in 2013 - IPC C21C7/00 

FIELD: metallurgy.

SUBSTANCE: for casting boron-containing steel including sulfur in amount of 0.01-0.03 wt %, chromium in amount of 0.15-0.25 wt %, titanium in amount of 0.02-0.045 wt %, after averaging blowing of steel produced in steelmaking unit, steel chemical composition is defined. In case sulfur content exceeds 0.012% slag and line additive are deoxidized at the following ratio: 10³ • (% S-0.012) • 90…110 kg CaO, where S is sulfur content after aforesaid blowing, %; 0.012 is boundary content of sulfur in steel, %; 90…110 CaO is lime consumption per every hundredth of sulfur exceeding 0.012%, kg. Then, slag is removed in steel out-of-furnace treatment in furnace-ladle assy, added are sand manganese-, silicon-, chromium- and molybdenum-bearing ferroalloys, carbon-bearing materials, ferrocalcium,ferrotitanium and ferroboron. After electric heating of steel to 10-15°C above preset temperature, aluminium rods is introduced to steel to produce aluminium content in finished steel approximating to lower limit of grade range, ferrocalcium and sulfur to carry out averaging blowing.

EFFECT: higher yield.

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