METHOD OF ROLLED THICK SHEETS FROM FABRICATED CHROME-MANGANESE STEEL Russian patent published in 2012 - IPC B22D11/00 

FIELD: process engineering.

SUBSTANCE: invention relates to ferrous metallurgy, particularly, to production of high-strength low-alloy steel for structures to be operated in high north. Proposed method comprises teeming steel into slabs, heating the latter, multipass rolling into sheets at preset controlled temperature range, water hardening and tempering. Steel features the following chemical composition, in wt %: 0.13-0.18 C; 0.4-0.7 Si; 1.2-1.8 Mn; 0.4-0.8 Cr; 0.20-0.45 Cu; 0.04-0.08 V; 0.02-0.05 Al; 0.02-0.05 Ti; 0.002-0.030 Ca; Nb≤0.06; Ce≤0.05; S≤0.008; P≤0.015; Fe making the rest. Continuous teeming is performed at the rate of 0.7-2.0 m/min. In teeming, crystalliser is oscillated along teeming axis at the rate of 30-270 min^-1 and amplitude of 2.5-10.0 mm. Continuous billet is cut. Produced slabs are heated and rolled with relative reduction of, at least, 50%. Last pass rolling is performed at 830-950°C to harden the sheets. Sheets are tempered at 600-690°C.

EFFECT: higher mechanical properties and antirust resistance.

3 tbl, 1 ex