Ultrafine bainite bridge cable steel and preparing method thereof

Abstract

The invention discloses ultrafine bainite bridge cable steel and a preparing method thereof, and belongs to wires for bridge cables and production thereof. The thermo-mechanical treatment + isothermalquenching technology is adopted for obtaining the cable steel; pre-deformation and low-temperature bainite isothermality are combined, refining technologies of microalloy refinement, controlled rolling and cooling refining, pre-deformation and low-temperature bainite isothermality are comprehensively used, an ultrafine bainite structure composed of non-carbonization bainite and retained austeniteis obtained, the tensile strength of the structure ranges from 1800 to 2100 MPa, and the ductility of the structure ranges from 12 to 20%; the preparing process of the ultrafine bainite bridge cablesteel comprises the steps of smelting, continuous casting, hot rolling, cutting, austenitizing, pre-deforming and low-temperature bainite isothermality. During pre-deforming, firstly, a cut hot-rolledwire rod is heated again to Ac3+50 DEG C to be subjected to austenitizing, heat preservation is carried out for 0.5 to 1 h, rapid cooling (the cooling speed is larger than 10 DEG C / s) to 220 to 280 DEG C is carried out, further warm rolling is carried out, the rolling reduction is 20 to 30%, then, the wire rod is put into a salt bath furnace at the temperature of 220 to 280 DEG C to be subjectedto isothermality treatment for 3 to 5 h, and isothermality bainite conversion is carried out; and the wire rod is taken out and subjected to air cooling to the room temperature.

Description

technical field [0001] The invention belongs to the field of wire rods for bridge cables and the production thereof, and relates to a bridge cable steel, in particular to a 2000MPa bridge cable steel and a production method thereof. Background technique [0002] With the rapid development of bridge construction technology, the design span of bridge construction continues to increase, and correspondingly higher requirements are put forward for the strength of the steel wire used as the main load-bearing component of the bridge, in order to reduce the weight of the bridge, improve safety, and reduce construction costs. maintenance costs. In order to meet the high-strength requirements of steel wires for bridge cables, the development of a new generation of high-strength and high-tenacity steel wires for bridge cables will be an inevitable trend in future development, which is of great significance for improving the core competitiveness of China's bridge industry and promoting ...

AI Technical Summary

Problems solved by technology

[0005] Although ultra-fine bainitic steel has excellent high strength and high toughness and plasticity, its preparation time is long, sometimes it takes several days or even dozens of days

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