Reinforcing method for high-strength tire bead steel wire material and preparation method for tire bead steel wires

Abstract

The invention provides a reinforcing method for high-strength tire bead steel wire material. According to the reinforcing method, on the condition of not changing the tensile strength and the carbon equivalent (Ceq) of the material, the content of carbon atoms is lowered to 0.74-0.78 wt% from 0.80-0.84 wt%, and the content of chromium atoms is increased to 0.20-0.30 wt% from 0.008 wt%. Thus, by lowering the content of carbon in raw material and adding chromium capable of refining pearlite lamellas, on the condition of the same carbon equivalent, the work hardening rate is increased, cementite dissolution in the cold-drawing process is restrained, and the twisting and layering problem of tire bead steel wires with the dependent variable epsilon being greater than or equal to 2.3 but smaller than or equal to 3.0 is solved; the mechanical property and the torsion property of the tire bead steel wires made of the material are improved, the cold-drawing limit is improved, the intermediate heat treatment process can be eliminated for partial thin-size and high-strength tire bead steel wires, and the production cost of the steel wires is greatly lowered.

Description

technical field [0001] The invention relates to the technical field of metal materials, in particular to a method for strengthening materials for producing high-strength bead steel wires and a preparation method for high-strength bead steel wires. Background technique [0002] At present, the diameter of high-strength bead steel wire for automobile tires is generally Φ5.5mm, and the chemical composition is generally implemented in accordance with the provisions of YB / T170.2, YB / T170.4 and GB / T14450-2004. With the development of the tire industry, high-strength (HT) bead wires have been widely used. In order to improve the tensile strength of bead wires, most of the high-strength bead wires currently produced are produced by materials with a carbon content of 0.82wt%. Too high a carbon content in the material makes cold drawing difficult and at the same time poses a risk of torsional delamination. [0003] With the improvement of cold drawing production level, ordinary Φ5.5m...

AI Technical Summary

Problems solved by technology

With the development of the tire industry, high-strength (HT) bead wires have been widely used. In order to improve the tensile strength of bead wires, most of the high-strength bead wires currently produced are produced by materials with a carbon content of 0.82wt%. Excessively high carbon content in the material makes cold drawing difficult and presents a risk of torsional delamination

[0003] With the improvement of cold drawing production level, ordinary Φ5.5mm materials are used to produce high-strength bead wire. At present, the maximum strain ε of cold drawing can reach about 2.7. To produce thinner high-strength bead wire, an intermediate wire must be added. Heat treatment process; In addition, ordinary Φ5.5mm raw materials are used to directly cold-draw high-strength bead wires. When the strain ε≥2.3, the torsional performance of the obtained high-strength bead wires is unstable, with low torsion values ​​and torsional delamination. Increased chance

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