HIGH-STRENGTH WELDED REBAR Russian patent published in 2013 - IPC C22C38/12 C21D8/08 

FIELD: metallurgy.

SUBSTANCE: rebar is produced from steel containing the following components at the following ratio in wt %: carbon 0.03-0.50, manganese 0.95-2.25, silicon 0.15-0.70, vanadium not over 0.08, niobium not over 0.08, iron and unavoidable impurities making the rest. It has microstructure consisting of tempered martensite, lower and upper bainite, magnitude δ₅ ≥ 12%, relationship σ_B/σ_T≥ 1.08, and total content of vanadium and niobium making at least 0.035%. Additionally, steel may contain, at least, 0.08 wt % of molybdenum and 0.08 wt % of titanium. Impurities comprise: sulfur not over 0.25, phosphorus not over 0.025, chromium not over 0.3, nickel not over 0.3, copper not over 0.45. Diameter of rebar (d) is related with carbon equivalent (C_e) by the following relationship: 0.36 ≤ Ce ≤ 0.60 at 10 ≤ d ≤ 18 mm, 0.40 ≤ Ce ≤ 0.60 at 20 ≤ d ≤ 28 mm, 0.45 ≤ Ce ≤ 0.60 at 32 ≤ d ≤ 40 mm, 0.48 ≤ Ce ≤ 0.60 at 42 ≤ d ≤ 70 mm.

EFFECT: high plasticity and resistance to high sign-variable loads, high operating properties.

4 cl, 2 tbl, 1 ex