IL42672A - Concrete-reinforcement steel - Google Patents

Claims (4)

1. Claims 42672/3 1. A weldable hot rolled steel, , for use as concrete reinforcement, which consists, apart from impurities conventional in such steels, of:- σ 0.15 - 0.24 b weight Si 0.30 - 0.60 tl II II Mn 1.0 1.5 II II II N 0.005 - 0.02 1» •1 H P up to 0.05 II II It S up to 0.05 it ' II It Cr up to 0»50 It It II Al up to 0.005 II II II Va 0.03 to 0.10 It It H balance iron, copper and nickel wherein the sum of the percentages of Mn and Cr does- not exceed p figure of about 1.5 and the sum of the percentages of Cu, Cr and Ni do not fall below a figure of 0.40%, the said steel after rolling is cooled down in still air without any additional treatment.

2. A steel according to claim 1, which contains 0.16 to 0,35$ copper.

3. A steel according to claim 1 or 2, which contains 0.10 to 0.17# nickel. r 4a A steel according to claim 1., 2 or 3 » which contains 0.17 to 0,22# carbon. f 5· Δ steel according to any preceding claim, which contains 0.40 to 0.60 silicon. 11. 42672/3 6. A steel according to any preceding claim, which contains 1,20 to 1<>40% manganese. ' 7. A steel according to any preceding claim, which contains 0.04 to 0.06 vanadiume 8. A method .of producing a weldable hot rolled concrete reinforcement steel member having a minimum yield poin of 50 kp/mm?_and-aii- elongatio on fracture of at. least 10%, which method comprises shaping said steel member by hot rolling and allowing the hot-rolled steel member to cool in substantially still air, the steel of said member containing iron, dopper, nickel, 0.15 to 0.24 carbon, 0.30 to 0.60% silicon, 1.0 to 1.5% manganese, 0.005 to 0.02% nitrogen, up to 0.05% phosphorus, up to 0.05% sulphur, up to 0.5% chromium, up to 0.005% aluminium and 0.03 to 0.1% vanadium, the sum of the- percentages of manganese and chromium not exceeding about 1.5% and "the sum of the percentages of copper, chromium and nickel not being less than 0.40% 9. A method according to claim 8, wherein the steel contains 0«16 to 0.35% copper. 10. A method according to claim 8 or 9» wherein the steel contains 0.10 to 0.17% nickel. 11. A method according to claim 8, 9 or 10, wherein the steel contains 0.17 to 0.22 carbon. 12. 42672/2 12. A method according to any one of claims 8 to 11 wherein the steel contains 0.40 to 0.60% silicon. 13* A method according to any one of claims 8 to 12, wherein the steel contains 1.20 to 1.40 manganese. 1

4. A method according to any one o claims 8 to 13, wherein the steel contains 0.04 to 0.065¾ vanadium. 15· A method according to any one of claim 8 to 14» wherein, prior to the hot-rolling step, a billet is formed by continuous casting, is cooled, is heated in a furnace, and is supplied to rollers for carrying out the hot rolling step while the billet from the furnace is still at a temperature in excess of 1000° C. 16. A method according to any one of claims 8 to 15, wherein ribs are formed on the member during the rolling step. 17. A method according to claim 8 and substantially as herein described; 18. A weldable concrete reinforcement steel member produced by the method of any one of claims 8 to 17. For the Applicants i R ARTNERS By :