A kind of manufacturing method of low-cost corrosion-resistant threaded steel bar

Abstract

The invention discloses a manufacturing method for low-cost corrosion-resistant twisted steel. Low-alloy steel waste or return scraps containing certain Cr, Ni, Cu, V and Mo are adopted as raw smelting materials of an electric arc furnace for being smelted, so that the alloy addition is reduced, and the corresponding alloying cost is lowered; and meanwhile, by adopting the electric arc furnace for smelting, the energy consumption of the electric arc furnace is obviously lower than the smelting energy consumption of a blast furnace and a converter. In addition, a heating furnace is omitted in the rolling process, and the rolling is completed by utilizing the heat of a continuous casting billet, so that the production cost is greatly reduced. According to the twisted steel manufactured through the process, the yield strength is greater than 500 MPa, the tensile strength is greater than 600 MPa, the percentage elongation after fracture is greater than 23%, and the corrosion resistance is higher than that of common HRB400 steel by 30-50% according to a detection method of YB / T 4367-2014.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a method for manufacturing low-cost corrosion-resistant threaded steel bars. Background technique [0002] Rebar is an important building material, which is widely used in the construction of houses, bridges, roads and other civil engineering, and is one of the core materials of modern buildings. The existing rebars mainly include HRB335 (20MnSi), HRB400 (20MnSiV, 20MnSiNb, 20MnTi), HRB500 and other three grades, the design idea is to add Nb, V, Ti and other alloying elements to the steel to improve the strength of the steel. On the other hand, the problem of reduced durability of rebar due to corrosion is becoming more and more serious, especially in coastal areas, marine engineering, marsh engineering and other specific environments, ordinary thread cannot meet the requirements of its service life, especially at present most of the building materials are made of sea san...

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Problems solved by technology

On the other hand, the problem of reduced durability of rebar due to corrosion is becoming more and more serious, especially in coastal areas, marine engineering, marsh engineering and other specific environments, ordinary thread cannot meet the requirements of its service life, especially at present most of the building materials are made of sea sand. , which is rich in a large amount of chloride ions. In the position of microscopic defects and inclusions, chloride ions can quickly penetrate the corrosion matrix to erode the steel and reduce the service life of the steel. Although stainless steel reinforcement can solve these problems, due to its high cost, It cannot be used in a large area in buildings, so it has become a research focus to improve the corrosion resistance of steel bars while reducing their cost

[0003] From the public information, the current research generally improves the corrosion resistance of rebar by adding alloy elements such as Cr, Ni, Cu, P, Mo, Sn, Ti, Nb, Re to the steel, and the process route adopted is mainly converter - Refining - Billet Continuous Casting - Heating - Controlled Rolling - Controlled Cooling. This process adopts the smelting mode of adding alloys after molten iron is smelted into molten steel. At the same time, a heating furnace is used to heat the billet. Although the product quality is relatively stable, relatively high cost

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