Hot rolled wire rod used for welding wire and production method of hot rolled wire rod

Abstract

The invention discloses a hot rolled wire rod used for a welding wire and a production method of the hot rolled wire rod. The wire rod comprises, by weight percent, 0.060%-0.075% of C, 0.80%-0.88% ofSi, 1.40%-1.48% of Mn, smaller than or equal to 0.013% of P, smaller than or equal to 0.010% of S, 0.005%-0.020% of Ti and the balance Fe and inevitable impurities. The hot rolled wire rod is preparedthrough a molten steel smelting process, a refining process, a casting process, a heating process, a temperature-controlled rolling process and a Stelmor slow cooling process which are conducted in sequence. According to the temperature-controlled rolling process, a steel blank is manufactured into the wire rod in a rolling manner after high-pressure water scale removing, the temperature of an inlet of a finishing mill is smaller than or equal to 880 DEG C, the wire rod moves forwards on a production line for at least 50 cm after final rolling and then is subjected to water cooling, spinningis conducted after cooling, and the spinning temperature ranges from 880 DEG C to 910 DEG C. According to the Stelmor slow cooling process, heat insulation slow cooling is conducted on the wire rod ona Stelmor slow cooling line, a heat insulation cover and a draught fan air opening are completely closed, and the cooling speed of the wire rod in a phase change temperature section is smaller than or equal to 0.8 DEG C / s. The structure, strength and plasticity of the wire rod are uniform, the strength difference of the whole rod is smaller than or equal to 25 MPa, and the hot rolled wire rod ismore suitable for high-speed drawing.

Description

technical field [0001] The invention belongs to the field of iron and steel material production, and in particular relates to a hot-rolled wire rod for welding wire and a production method thereof. Background technique [0002] ER70S-6 welding wire is currently the most widely used carbon steel series gas shielded welding wire, usually drawn from a hot-rolled wire rod with a diameter of 5.5mm. [0003] Due to the increasingly fierce competition in the industry and the pressure of production costs, welding wire manufacturers urgently need to increase the drawing speed in the process of welding wire processing in order to improve production efficiency. Correspondingly, this affects the performance of welding wire wire rods, especially the The performance related to the above-mentioned drawing speed puts forward higher standards and requirements. [0004] After research, the peelability of the oxide scale on the surface of the wire rod, the structure of the wire rod, and the u...

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Problems solved by technology

[0006] For another example, the hard phase structure such as abnormal bainite or martensite in the part of the wire rod seriously affects the continuity of high plasticity in other parts of the wire rod, making the overall deformation of the wire rod uneven and resulting in wire breakage during drawing

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