Annealing-free low-carbon steel coil rod and production method thereof

Abstract

The invention provides an annealing-free low-carbon steel coil rod and a production method thereof. The annealing-free low-carbon steel coil rod comprises the following chemical components: 0.04-0.10% of C, 0.01-0.10% of Si, 0.20-0.35% of Mn, at most 0.015% of P, at most 0.010% of S, at most 0.0060% of N, 0.0030-0.0060% of total oxygen, 0.0020-0.0080% of total aluminum, at most 0.1% of inevitable impurity and the balance of iron. The manufacturing method comprises the steps of converter smelting, LF (ladle furnace) refining, continuous casting and rolling, wherein incomplete deoxidation occurs at the tapping side of a converter, the aluminum content of molten steel is reduced by using the high oxygen activity of the molten steel, the carbonization of the molten steel in the refining process is inhibited, bloom protection casting is performed, the temperature for double module input is controlled at 900-920 DEG C, the loop laying temperature is 870-900 DEG C, the speed of a roller way is 0.2-0.4 m/s, and a blower is closed. Thus, the vacuum treatment procedure is omitted, the technical process is shortened, the production cost is lowered, and the requirement of users for canceling the annealing technique in the drawing process is satisfied. For the annealing-free low-carbon steel coil rod produced according to the components and the production method provided by the invention, the grain size is controlled at 20-30 um, the tensile strength is no more than 350 MPa, and the reduction of area is no less than 75%.

Description

technical field [0001] The invention belongs to the field of low-carbon steel manufacturing, and in particular relates to an annealing-free low-carbon steel wire rod and a manufacturing method thereof. Background technique [0002] With the rapid development of the national economy and the further strengthening of social environmental protection awareness, there are extensive requirements for low-carbon and ultra-low-carbon steel. In addition to traditional low-carbon wire drawing materials, high-performance galvanized steel wire and low-carbon steel fiber wire And the market of low carbon conductive steel wire is also developing rapidly. The drawing production process of low-carbon steel wire requires that the wire rod has low strength and high plasticity. The low tensile strength and high plasticity can cancel the annealing heat treatment process in the drawing process, thereby reducing environmental pollution and carbon emissions. [0003] Patent No. CN200710159224.7 dis...

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Problems solved by technology

Niobium and boron alloy elements are added to the steel, which increases the cost of the alloy

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