BAR ROLLING METHOD Russian patent published in 2007 - IPC C21D8/06 C22C38/14 

FIELD: rolled stock production, possibly hot rolling of round bars of low alloy steel for cold die forging of fastening members.

SUBSTANCE: method comprises steps of heating blank up to 1100 - 1280°C; multi-pass hot rolling at reducing in grooved rolls at temperature of rolling process termination in range 950 - 1100°C; water cooling of rolled piece till 850 - 950°C. For rolled blank multi-pass rolling is realized at total elongation degree no less than 16. For cast billet multi-pass rolling is realized at total elongation degree no less than 36. Rolled bars are of alloy steel containing, mass %: carbon, 0.20 - 0.33; silicon, 0.17 - 035; manganese, 0.9 - 1.3; boron, 0.001 - 0.005; aluminum, 0.01 - 0.05; titanium, 0.01 or more; phosphorus, 0.035 of less; sulfur, 0.035 or less; chrome, 0.25 or less; nickel, 0.30 or less; copper, 0.30 or less; nitrogen, 0.012 or less; iron, the balance.

EFFECT: less loss of yield, improved quality of rolled bars.

2 cl, 3 tbl, 2 ex