METHOD OF PRODUCING CONTINUOUSLY-CAST STEEL BILLETS Russian patent published in 2012 - IPC B22D11/00 

FIELD: process engineering.

SUBSTANCE: invention relates to iron and steel metallurgy, particularly, to continuous casting of billets from low-carbon low-alloy steel and may be used in continuous casting of large-diameter gas-and-oil pipes at continuous casting machines with curved process line and vertical section. Proposed method comprises feeding tube-grade steel into crystalliser from intermediate ladle with overheating to above liquidus temperature, drawing billet from crystalliser at variable speed and cooling down the billet in zone of secondary cooling. Drawing speed is defined from design formula that allows for billet standard size, continuous casting machine type, steel composition, and steel overheating temperature. Biller cooling after crystalliser is performed on straight vertical section and on curved section of secondary cooling by jets of water-air jets. Steel overheat temperature in intermediate ladle is set 5…45°C higher than liquidus temperature.

EFFECT: ruling out inner and outer cracks on billet, higher yield of accepted articles and efficiency.

1 tbl, 1 ex